SC 14D9

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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 14D-9

SOLICITATION/RECOMMENDATION STATEMENT
PURSUANT TO SECTION 14(d)(4) OF THE
SECURITIES EXCHANGE ACT OF 1934

GENZYME CORPORATION
(Name of Subject Company)

GENZYME CORPORATION
(Name of Person(s) Filing Statement)

Common Stock, par value $0.01 per share
(Title of Class of Securities)

372917104
(CUSIP Number of Common Stock)

Peter Wirth
Executive Vice President
Genzyme Corporation
500 Kendall Street
Cambridge, Massachusetts 02142
(617) 252-7500
(Name, Address and Telephone Number of Person Authorized
to Receive Notices and Communications on Behalf of the Person(s) Filing Statement)

With copies to:
Paul M. Kinsella Ropes & Gray LLP Prudential Tower 800 Boylston Street Boston, Massachusetts 02199 (617) 951-7000	Andrew R. Brownstein Wachtell, Lipton, Rosen & Katz 51 West 52nd St New York, New York 10019 (212) 403-1000

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Check the box if the filing relates solely to preliminary communications made before the commencement of a tender offer.

Item 1.    Subject Company Information.

(a)   Name and Address.

        The name of the subject company is Genzyme Corporation, a Massachusetts corporation (the "Company" or "Genzyme"), and the address of the principal executive offices of the Company is 500 Kendall Street, Cambridge, MA 02142. The telephone number of the principal executive offices of the Company is (617) 252-7500.

(b)   Securities.

        The title of the class of equity securities to which this Solicitation/Recommendation Statement on Schedule 14D-9 (this "Schedule 14D-9") relates is the Company's common stock, par value $.01 per share (the "Shares"). As of September 30, 2010, there were 257,339,881 Shares issued and outstanding.

Item 2.    Identity and Background of Filing Person.

(a)   Name and Address.

        The name, business address and business telephone number of the Company, which is the person filing this Schedule 14D-9 and the subject company, are set forth in Item 1(a) above.

(b)   Tender Offer.

        This Schedule 14D-9 relates to the unsolicited tender offer by GC Merger Corp., a Massachusetts corporation ("Offeror") and wholly-owned subsidiary of Sanofi-Aventis, a French société anonyme ("Sanofi"), to purchase all of the outstanding Shares at a purchase price of $69.00 per Share (the "Offer Price"), net to the selling shareholders in cash, without interest thereon and less any required withholding taxes, upon the terms and subject to the conditions set forth in the Offer to Purchase, dated October 4, 2010 (the "Offer to Purchase"), and in the related Letter of Transmittal (which, together with the Offer to Purchase, constitutes the "Offer"), included as Exhibits (a)(1)(A) and (a)(1)(B) to the Tender Offer Statement on Schedule TO (as amended or supplemented from time to time, the "Schedule TO") filed by Sanofi and Offeror with the Securities and Exchange Commission (the "SEC") on October 4, 2010. The Schedule TO states that the Offer will expire at 11:59 p.m., New York City time, on Friday, December 10, 2010, unless Sanofi and Offeror extend the Offer. The Offer is also described in the Schedule TO.

        The Schedule TO provides that the Offer is subject to the following 14 conditions:

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the Company's shareholders having validly tendered and not withdrawn prior to the expiration of the Offer, a number of Shares, which, together with the Shares owned by Sanofi and its subsidiaries (including Offeror), represents at least a majority of the total number of Shares then outstanding on a fully diluted basis;

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the Company's board of directors (the "Company Board") having approved the Offer and the second-step merger proposed to be undertaken by Sanofi and Offeror upon consummation of the Offer (the "Proposed Merger") such that, or Sanofi and Offeror being otherwise satisfied in their sole discretion that, the restrictions on business combinations with interested shareholders set forth in Chapter 110F of the Massachusetts General Laws and any other applicable anti-takeover laws are inapplicable to the Offer and the Proposed Merger;

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the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended (the "HSR Act"), applicable to the purchase of Shares under this Offer having expired or been terminated, and any other approvals or notifications under applicable foreign antitrust, competition or merger control laws applicable to the purchase of Shares in the Offer having been obtained or made;

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the Company not having entered into or effectuated any agreement or transaction with any person or entity having the effect of impairing Offeror's or Sanofi's ability to acquire the

Company or otherwise diminishing the expected value to Sanofi of the acquisition of the Company;

•

there shall not be threatened, instituted or pending any action or proceeding by any government, governmental authority or agency or any other person, domestic, foreign or supranational, before any court or governmental authority or agency, domestic, foreign or supranational, (i) challenging or seeking to, or which is reasonably likely to, make illegal, delay or otherwise, directly or indirectly, restrain or prohibit the making of the Offer or the Proposed Merger, the acceptance for payment of or payment for some or all of the Shares by Offeror or any of its subsidiaries or affiliates or the consummation by Offeror or any of its subsidiaries or affiliates of a merger or other similar business combination involving the Company, (ii) seeking to obtain material damages in connection with, or otherwise directly or indirectly relating to, the transactions contemplated by the Offer or any such merger or other similar business combination, (iii) seeking to restrain or prohibit the exercise of full rights of ownership or operation by Offeror or any of its subsidiaries or affiliates of all or any portion of its business or assets or those of the Company or any of its or the Company's respective subsidiaries or affiliates or to compel Offeror or any of its subsidiaries or affiliates to dispose of or hold separate all or any portion of its business or assets or those of the Company or any of its or the Company's respective subsidiaries or affiliates or seeking to impose any limitation on Offeror or any of its subsidiaries' or affiliates' ability to conduct such businesses or own such assets, (iv) seeking to impose or confirm limitations on Offeror's ability or that of any of its subsidiaries or affiliates effectively to exercise full rights of ownership of the Shares, including the right to vote any Shares acquired or owned by Offeror or any of its subsidiaries or affiliates on all matters properly presented to the Company's shareholders, (v) seeking to require divestiture by Offeror or any of its subsidiaries or affiliates of any Shares, (vi) seeking any material diminution in the benefits expected to be derived by Offeror or any of its subsidiaries or affiliates as a result of the transactions contemplated by the Offer or any merger or other business combination involving the Company, (vii) adversely affecting Offeror's financing of the Offer or any merger or other business combination involving the Company or (viii) that otherwise, in Offeror's reasonable judgment, has or may have material adverse significance with respect to either the value of the Company or any of our subsidiaries or affiliates or the value of the Shares to Offeror or any of its subsidiaries or affiliates;

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there shall not have been any action taken, or any statute, rule, regulation, interpretation, judgment, injunction, order or decree proposed, enacted, enforced, promulgated, amended, issued or deemed applicable to Sanofi, Offeror or any of their subsidiaries or affiliates, the Offer, the acceptance for payment of or payment for Shares by Offeror, or any merger or other business combination involving the Company, by any court, government or governmental authority or agency, domestic, foreign or supranational (other than the application of the waiting period provisions of the HSR Act to the Offer or to any such merger or other business combination), that, in Offeror's reasonable judgment, does or may, directly or indirectly, result in any of the consequences referred to in clauses (i) through (viii) of the paragraph above;

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there shall not have occurred or been threatened any change (or any development involving a prospective change) in the business, assets, liabilities, financial condition, capitalization, operations, results of operations or prospects of the Company or any of its affiliates that, in Offeror's reasonable judgment, is or may be materially adverse to the Company or any of our affiliates, and Offeror shall not have become aware of any facts that, in Offeror's reasonable judgment, would have material adverse significance with respect to either the value of the Company or any of our affiliates or the value of the Shares to Offeror or any of its affiliates;

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there shall not have occurred (i) any general suspension of trading in, or limitation on prices for, securities on any national securities exchange or in the over-the-counter market, (ii) any decline

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in either the Dow Jones Industrial Average, the Standard and Poor's Index of 500 Industrial Companies or the NASDAQ-100 Index by an amount in excess of 15%, measured from the close of business on October 1, 2010, (iii) any change in the general political, market, economic or financial conditions in the United States that, in Offeror's reasonable judgment, could have a material adverse effect on the business, assets, liabilities, financial condition, capitalization, operations, results of operations or prospects of the Company and our subsidiaries, taken as a whole, (iv) the declaration of a banking moratorium or any suspension of payments in respect of banks in the United States, (v) any material adverse change (or development or threatened development involving a prospective material adverse change) in United States dollars or any other currency exchange rates or a suspension of, or a limitation on, the markets therefor, (vi) the commencement of a war, armed hostilities or other international or national calamity directly or indirectly involving the United States or any attack on, outbreak or act of terrorism involving the United States, (vii) any limitation (whether or not mandatory) by any governmental authority or agency on, or any other event that, in Offeror's reasonable judgment, may adversely affect, the extension of credit by banks or other financial institutions or (viii) in the case of any of the foregoing existing as of the close of business on October 1, 2010, a material acceleration or worsening thereof;

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(i) there shall not have been a tender or exchange offer for some or all of the Shares publicly proposed to be made or made by another person (including the Company or any of our subsidiaries or affiliates), or publicly disclosed, and Offeror shall not have otherwise learned that any person or "group" (as defined in Section 13(d)(3) of the Securities Exchange Act of 1934, as amended (the "Exchange Act")) has acquired or proposes to acquire beneficial ownership of more than 5% of any class or series of capital stock of the Company (including the Shares), through the acquisition of stock, the formation of a group or otherwise, or has been granted any option, right or warrant, conditional or otherwise, to acquire beneficial ownership of more than 5% of any class or series of capital stock of the Company (including the Shares) other than acquisitions for bona fide arbitrage purposes only and other than as disclosed in a Schedule 13D or 13G on file with the SEC on October 1, 2010, (ii) any such person or group which, prior to October 1, 2010, had filed such a Schedule with the SEC shall not have acquired or proposed to acquire beneficial ownership of additional shares of any class or series of capital stock of the Company, through the acquisition of stock, the formation of a group or otherwise, constituting 1% or more of any such class or series, or granted any option, right or warrant, conditional or otherwise, to acquire beneficial ownership of additional shares of any class or series of capital stock of the Company constituting 1% or more of any such class or series, (iii) no person or group shall have entered into a definitive agreement or an agreement in principle or made a proposal with respect to a tender or exchange offer or a merger, consolidation or other business combination with or involving the Company or (iv) no person shall have filed a Notification and Report Form under the HSR Act or made a public announcement reflecting an intent to acquire the Company or any assets or securities of the Company;

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the Company or any of its subsidiaries shall not have (i) split, combined or otherwise changed, or authorized or proposed the split, combination or other change of, the Shares or its capitalization, (ii) acquired or otherwise caused a reduction in the number of, or authorized or proposed the acquisition or other reduction in the number of, outstanding Shares or other securities, (iii) issued or sold, or authorized or proposed the issuance or sale of, any additional Shares, shares of any other class or series of capital stock, other voting securities or any securities convertible into, or options, rights or warrants, conditional or otherwise, to acquire, any of the foregoing (other than the issuance of Shares pursuant to and in accordance with the terms in effect on December 31, 2009, of employee stock options outstanding prior to such date), or any other securities or rights in respect of, in lieu of, or in substitution or exchange for any shares of our capital stock, (iv) permitted the issuance or sale of any shares of any class of

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capital stock or other securities of any subsidiary of the Company, (v) declared, paid or proposed to declare or pay any dividend or other distribution on any shares of capital stock of the Company, (vi) altered or proposed to alter any material term of any outstanding security, issued or sold, or authorized or proposed the issuance or sale of, any debt securities or otherwise incurred or authorized or proposed the incurrence of any debt other than in the ordinary course of business, (vii) authorized, recommended, proposed or announced our intent to enter into or entered into an agreement with respect to or effected any merger, consolidation, liquidation, dissolution, business combination, acquisition of assets, disposition of assets or relinquishment of any material contract or other right of the Company or any of our subsidiaries or any comparable event not in the ordinary course of business, (viii) authorized, recommended, proposed or announced our intent to enter into or entered into any agreement or arrangement with any person or group that, in Offeror's reasonable judgment, has or may have material adverse significance with respect to either the value of the Company or any of our subsidiaries or affiliates or the value of the Shares to Offeror or any of its subsidiaries or affiliates, (ix) adopted, entered into or amended any employment, severance, change of control, retention or other similar agreement, arrangement or plan with or for the benefit of any of our officers, directors, employees or consultants or made grants or awards thereunder, in each case other than in the ordinary course of business or adopted, entered into or amended any such agreements, arrangements or plans so as to provide for increased benefits to officers, directors, employees or consultants as a result of or in connection with the making of the Offer, the acceptance for payment of or payment for some of or all the Shares by Offeror or Offeror's consummation of any merger or other similar business combination involving the Company (including, in each case, in combination with any other event such as termination of employment or service), (x) except as may be required by law, taken any action to terminate or amend or materially increase liability under any employee benefit plan (as defined in Section 3(2) of the Employee Retirement Income Security Act of 1974) of the Company or any of our subsidiaries, or Offeror shall not have become aware of any such action which was not previously announced, (xi) transferred into escrow (or other similar arrangement) any amounts required to fund any existing benefit, employment, severance, change of control or other similar agreement, in each case other than in the ordinary course of business, or (xii) amended, or authorized or proposed any amendment to, our articles of organization or by-laws (or other similar constituent documents) and Offeror shall not have become aware that the Company or any of our subsidiaries shall have amended, or authorized or proposed any amendment to, their respective articles of organization or bylaws (or other similar constituent documents) which has not been previously disclosed;

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Offeror shall not have become aware (i) that any material contractual right of the Company or any of our subsidiaries has been impaired or otherwise adversely affected or that any material amount of indebtedness of the Company or any of our subsidiaries has been accelerated or has otherwise become due or become subject to acceleration prior to its stated due date, in each case with or without notice or the lapse of time or both, as a result of or in connection with the Offer or the consummation by Offeror or any of its subsidiaries or affiliates of a merger or other similar business combination involving the Company or (ii) of any covenant, term or condition in any instrument or agreement of the Company or any of our subsidiaries that, in Offeror's reasonable judgment, has or may have material adverse significance with respect to either the value of the Company or any of our affiliates or the value of the Shares to Offeror or any of its affiliates (including any event of default that may ensue as a result of or in connection with the Offer, the acceptance for payment of or payment for some or all of the Shares by Offeror or Offeror's consummation of a merger or other similar business combination involving the Company);

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Offeror or any of its affiliates shall not have entered into a definitive agreement or announced an agreement in principle with the Company providing for a merger or other similar business combination with the Company or any of our subsidiaries or the purchase of securities or assets of the Company or any of our subsidiaries, and Offeror and the Company shall not have reached any other agreement or understanding pursuant to which it is agreed that the Offer will be terminated;

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the Company or any of our subsidiaries shall not have (i) granted to any person proposing a merger or other business combination with or involving the Company or any of our subsidiaries or the purchase of securities or assets of the Company or any of our subsidiaries any type of option, warrant or right which, in Offeror's reasonable judgment, constitutes a "lock-up" device (including a right to acquire or receive any Shares or other securities, assets or business of the Company or any of our subsidiaries) or (ii) paid or agreed to pay any cash or other consideration to any party in connection with or in any way related to any such business combination or purchase; and

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each required approval, permit, authorization, extension, action or non-action, waiver or consent of any governmental authority or agency shall have been obtained on terms satisfactory to Sanofi and Offeror and any waiting period or extension thereof imposed by any government or governmental authority or agency with respect to the Offer shall have expired.

        The Schedule TO states that Sanofi has formed Offeror in connection with the Offer. The Schedule TO states that the registered office of Sanofi is located at 174, avenue de France, 75013, Paris, France and its telephone number at that address is + 33 1 53 77 40 00. The Schedule TO states that the principal executive offices of Offeror are located at 55 Corporate Drive, Bridgewater, New Jersey 08807 and its telephone number at that address is +1 (908) 981-5000.

Item 3.    Past Contacts, Transactions, Negotiations and Agreements.

Conflicts of Interest

        Except as set forth in this Schedule 14D-9 or in the excepts from the Company's 2010 Definitive Proxy Statement, dated April 26, 2010, as amended (the "2010 Proxy Statement") filed as Exhibit (e)(1) to this Schedule 14D-9 (and incorporated by reference into this Item 3), as of the date of this Schedule 14D-9, to the knowledge of the Company, there are no material agreements, arrangements or understandings and no actual or potential conflicts of interest between the Company or its affiliates and (i) its executive officers, directors or affiliates, or (ii) Sanofi, Offeror or their respective executive officers, directors or affiliates. For further information with respect to these matters, see the 2010 Proxy Statement under the headings: "Security Ownership"; "Director Compensation"; "Compensation Discussion and Analysis"; "Summary Compensation Table"; "Grant of Plan-Based Awards"; "Executive Employment Arrangements"; "Outstanding Equity Awards at Fiscal Year-End" and "Potential Payments Upon Termination or Change in Control."

(a)   Arrangements with Current Executive Officers, Directors and Affiliates of the Company.

        The following is a discussion of material agreements, arrangements, understandings and actual or potential conflicts of interest of the Company and its affiliates that relate to the Offer and the Proposed Merger. Additional material agreements, arrangements, understandings and actual or potential conflicts of interest of the Company and its affiliates that are unrelated to the Offer and the Proposed Merger are discussed in Exhibit (e)(1).

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Interests of Certain Persons

        Certain members of management and the Company Board may be deemed to have certain interests in the Offer and Proposed Merger that are different from or in addition to the interests of the Company's shareholders generally. The Company Board was aware of these interests and considered that such interests may be different from or in addition to the interests of the Company's shareholders generally, among other matters, in determining not to approve the Offer and Proposed Merger.

Treatment of Shares, Stock Options and Restricted Stock Units In Connection with the Offer and Proposed Merger

Treatment of Shares

        If the directors and executive officers of the Company who own Shares were to tender their Shares for purchase pursuant to the Offer, they would receive the same cash consideration for their Shares on the same terms and conditions as the other shareholders of the Company. As discussed below in Item 4 "The Solicitation or Recommendation," to the Company's knowledge, after making reasonable inquiry, none of the Company's executive officers, directors, affiliates or subsidiaries currently intends to tender into the Offer or sell any Shares held of record or beneficially owned by such person. If the Proposed Merger were to be consummated, any Shares held of record or beneficially owned by a director or executive officer that are not tendered into the Offer, would be converted into the right to receive the Offer Price at the effective time of the Proposed Merger (the "Effective Time").

        The approximate value of the cash payments that each director and executive officer of the Company would receive in exchange for his or her Shares in the Offer if they were to tender their Shares is set forth in the table below. This information is based on the number of Shares held by the Company's directors and executive officers as of September 30, 2010.

Name of Executive Officer or Director	Number of Shares		Cash Consideration for Shares
Scott Canute		0	$	0
Zoltan Csimma		12,663		873,747
Thomas DesRosier		11,754		811,026
James Geraghty		4,631		319,539
David P. Meeker(1)		11,371		784,599
Richard Moscicki		21,048		1,452,312
Alan Smith		37,534		2,589,846
Sandford D. Smith		20,671		1,426,299
Henri A. Termeer(2)		708,878		48,912,582
Peter Wirth(3)		15,386		1,061,634
Michael S. Wyzga		27,599		1,904,331
Douglas Berthiaume(4)		75,206		5,189,214
Robert Bertolini		2,375		163,875
Gail Boudreaux		5,000		345,000
Steven Burakoff		0		0
Robert Carpenter		31,825		2,195,925
Charles L. Cooney(5)		12,011		828,759
Victor Dzau(6)		7,550		520,950
Eric Ende		0		0
Dennis Fenton(7)		355		24,495

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Name of Executive Officer or Director	Number of Shares		Cash Consideration for Shares
Connie Mack III		5,000		345,000
Richard F. Syron		5,011		345,759
Ralph Whitworth(8)		10,608,623		731,994,987

(1)

The stock beneficially owned by Dr. Meeker includes 621 shares held by his wife and 495 shares held by his children. Dr. Meeker disclaims beneficial ownership of all shares held by his wife and children.

(2)

The stock beneficially owned by Mr. Termeer includes 2,371 shares held by his wife and 1,256 shares held in trusts for the benefit of Mr. Termeer's children. Mr. Termeer disclaims beneficial ownership of all shares held by his wife and the trusts.

(3)

The stock beneficially owned by Mr. Wirth includes 148 shares held in an IRA account.

(4)

The stock beneficially owned by Mr. Berthiaume includes 4,048 shares held by his wife. Mr. Berthiaume disclaims beneficial ownership of all shares held by his wife.

(5)

The stock beneficially owned by Dr. Cooney includes 7,164 shares held jointly with his wife, 240 shares held individually by his wife, 1,882 shares held by his son and 600 shares held by his grandchildren. Dr. Cooney disclaims beneficial ownership of all shares held individually by his wife, son and grandchildren.

(6)

The stock beneficially owned by Dr. Dzau includes 2,550 shares held by his wife's trust.

(7)

The stock beneficially owned by Dr. Fenton is held jointly with his wife in a living trust account.

(8)

Mr. Whitworth is one of the principals of Relational Investors, LLC, or "RILLC." RILLC is the record owner of 100 shares and sole general partner, or the sole managing member of the general partner, of Relational Investors, L.P. , Relational Fund Partners, L.P., Relational Coast Partners, L.P., RH Fund 1, L.P., RH Fund 6, L.P. Relational Investors III, L.P., Relational Investors VIII, L.P., Relational Investors IX, L.P., Relational Investors X, L.P., Relational Investors XV, L.P., Relational Investors XVI, L.P., Relational Investors XX, L.P., Relational Investors XXII, L.P., Relational Investors XXIII, L.P., and Relational Investors Alpha Fund I, L.P. These limited partnerships own a total of 7,693,166 shares. An additional 2,234,482 shares are held in accounts managed by RILLC and an additional 408,500 shares are held through co-investment arrangements with Relational Investors VIII, L.P. Mr. Whitworth disclaims beneficial ownership of these securities except to the extent of his pecuniary interest therein. The business address for the entities listed above is c/o Relational Investors LLC, 12400 High Bluff Drive, Suite 600, San Diego, CA 92130.

Treatment of Stock Options

        Upon a change in control of the Company, all unvested outstanding stock options held by directors and executive officers of the Company become fully exercisable, whether or not vested. In connection with the Proposed Merger, the Compensation Committee of the Company Board could provide, upon written prior notice, that outstanding stock options held by directors and executive officers of the Company would terminate not less than 20 days after the date of such notice. Assuming all outstanding stock options become vested following consummation of the Offer and are exercised immediately prior to the consummation of the Proposed Merger, the approximate value of the net cash payments that each director and executive officer of the Company could receive for the Shares from option exercises (i.e. the excess, if any, of the Offer Price over the per Share exercise price of the respective options

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multiplied by the total number of Shares subject to such options) is set forth in the table below. This information is based on the number of options with a per Share exercise price less than the Offer Price held by the Company's directors and executive officers as of September 30, 2010, assuming the Proposed Merger had been completed on September 30, 2010.

Name of Executive Officer or Director	Number of Shares Subject to Vested Stock Options		Cash Consideration for Vested Stock Options		Number of Shares Subject to Unvested Stock Options		Cash Consideration for Unvested Stock Options		Total Cash Consideration Stock Options in Proposed Merger
Scott Canute		8,550	$	149,454		84,200	$	1,186,816	$	1,336,270
Zoltan Csimma		264,178		5,287,257		33,775		363,206		5,650,463
Thomas DesRosier		150,532		2,032,622		38,905		452,878		2,485,500
James Geraghty		183,549		2,711,939		28,950		311,319		3,023,258
David P. Meeker		311,210		5,120,865		96,500		1,146,795		6,267,660
Richard Moscicki		392,204		7,903,306		46,802		503,294		8,406,600
Alan Smith		367,129		7,033,520		46,802		503,294		7,536,814
Sandford D. Smith		220,850		1,831,309		86,850		933,957		2,765,266
Henri A. Termeer		3,261,017		61,568,348		386,000		4,150,920		65,719,268
Peter Wirth		647,195		13,592,270		86,850		933,957		14,526,227
Michael S. Wyzga		397,650		5,807,928		86,850		933,957		6,741,885
Douglas Berthiaume		93,000		1,087,890		7,125		124,545		1,212,435
Robert Bertolini		7,125		139,508		7,125		124,545		264,053
Gail Boudreaux		75,000		808,350		7,125		124,545		932,895
Steven Burakoff		0		0		7,125		124,545		124,545
Robert Carpenter		90,010		1,373,225		7,125		124,545		1,497,770
Charles L. Cooney		63,010		490,685		7,125		124,545		615,230
Victor Dzau		75,900		1,057,041		7,125		124,545		1,181,586
Eric Ende		0		0		7,125		124,545		124,545
Dennis Fenton		0		0		7,125		124,545		124,545
Connie Mack III		82,000		752,990		7,125		124,545		877,535
Richard F. Syron		45,000		341,550		7,125		124,545		466,095
Ralph Whitworth		7,125		116,423		7,125		124,545		240,968

Treatment of Restricted Stock Units

        Upon a change in control of the Company, all unvested non-performance based restricted stock units ("RSUs") held by directors and executive officers of the Company become fully vested, and a pro rated amount of unvested performance based RSUs held by directors and executive officers of the Company become fully vested, based on a ratio of the number of months competed in performance period through the date of a change in control and the total number of months in such performance period. Assuming all unvested non-performance based RSUs and the pro rated portion of unvested performance based RSUs become vested upon consummation of the Offer, the Shares issued thereunder would be cancelled and converted in the Proposed Merger into a right to receive the Offer Price (subject to any applicable withholding of taxes required by applicable law). The approximate value of the cash payments that each director and executive officer of the Company would receive in exchange for cancellation of the Shares underlying such RSUs is set forth in the table below. This information is based on Offer Price and the number of RSUs held by the Company's directors and

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executive officers as of September 30, 2010, assuming the Proposed Merger had been completed on September 30, 2010.

Name of Executive Officer or Director	Number of RSUs		Cash Consideration for RSUs
Scott Canute		28,564	$	1,970,916
Zoltan Csimma		7,026		484,794
Thomas DesRosier		13,297		917,493
James Geraghty		10,938		754,722
David P. Meeker		34,252		2,363,388
Richard Moscicki		17,682		1,220,058
Alan Smith		9,735		671,715
Sandford D. Smith		18,064		1,246,416
Henri A. Termeer		80,682		5,567,058
Peter Wirth		32,814		2,264,166
Michael S. Wyzga		32,814		2,264,166
Douglas Berthiaume		2,375		163,875
Robert Bertolini		2,375		163,875
Gail Boudreaux		2,375		163,875
Steven Burakoff		2,375		163,875
Robert Carpenter		2,375		163,875
Charles L. Cooney		2,375		163,875
Victor Dzau		2,375		163,875
Eric Ende		2,375		163,875
Dennis Fenton		2,375		163,875
Connie Mack III		2,375		163,875
Richard F. Syron		2,375		163,875
Ralph Whitworth		2,375		163,875

        The following table sets forth the approximate amount of consideration that each director and executive officer of the Company would be entitled to receive in connection with the consummation of the Offer and Proposed Merger as a result of the Company equity interests held by each director or executive officer as of September 30, 2010, assuming the Proposed Merger had been completed on September 30, 2010. The table does not include "change in control" payments to the executive officers upon completion of the Offer and payments if the executive officers were to be terminated in

9

connection with the Offer. Such payments are detailed below in the section entitled "Other Payments upon a Change in Control or Termination."

Name of Executive Officer or Director	Cash Consideration for Shares			Cash Consideration for RSUs		Cash Consideration for Stock Options		Total Cash Consideration in connection with Offer and Proposed Merger
Scott Canute	$	0		$	1,970,916	$	1,336,270	$	3,307,186
Zoltan Csimma		873,747			484,794		5,650,463		7,009,004
Thomas DesRosier		811,026			917,493		2,485,500		4,214,019
James Geraghty		319,539			754,722		3,023,258		4,097,519
David P. Meeker		784,599			2,363,388		6,267,660		9,415,647
Richard Moscicki		1,452,312			1,220,058		8,406,600		11,078,970
Alan Smith		2,589,846			671,715		7,536,814		10,798,375
Sandford D. Smith		1,426,299			1,246,416		2,765,266		5,437,981
Henri A. Termeer		48,912,582			5,567,058		65,719,268		120,198,908
Peter Wirth		1,061,634			2,264,166		14,526,227		17,852,027
Michael S. Wyzga		1,904,331			2,264,166		6,741,885		10,910,382
Douglas Berthiaume		5,189,214			163,875		1,212,435		6,565,524
Robert Bertolini		163,875			163,875		264,053		591,803
Gail Boudreaux		345,000			163,875		932,895		1,441,770
Steven Burakoff		0			163,875		124,545		288,420
Robert Carpenter		2,195,925			163,875		1,497,770		3,857,570
Charles L. Cooney		828,759			163,875		615,230		1,607,864
Victor Dzau		520,950			163,875		1,181,586		1,866,411
Eric Ende		0			163,875		124,545		288,420
Dennis Fenton		24,495			163,875		124,545		312,915
Connie Mack III		345,000			163,875		877,535		1,386,410
Richard F. Syron		345,759			163,875		466,095		975,729
Ralph Whitworth		731,994,987	(1)		163,875		240,968		732,399,830

(1)

This amount represents the consideration that would be payable in relation to shares held by RILLC and its affiliated entities as of September 30, 2010, assuming the Proposed Merger had been completed on September 30, 2010. RILLC is the investment firm which Mr. Whitworth founded and of which he serves as a principal. Mr. Whitworth disclaims beneficial ownership of these securities except to the extent of his pecuniary interest therein.

Employment and Severance Agreements

        Under the employment agreements with Henri Termeer and Peter Wirth, upon termination by the Company following a change in control of the Company, other than for cause or disability or by Mr. Termeer or Mr. Wirth for good reason, the Company must:

•

make a lump sum severance payment of three times the sum of his annual salary and annual cash incentive;

•

continue life, disability, accident and health insurance coverage for three years, except to the extent comparable benefits are provided by a new employer; and

•

in certain circumstances, pay legal costs and relocation expenses associated with the termination.

        Under the severance agreements with Scott Canute, Zoltan Csimma, Thomas DesRosier, James Geraghty, David P. Meeker, Richard Moscicki, Alan Smith, Sanford D. Smith and Michael S. Wyzga,

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upon termination of employment following a change in control of the Company, by the Company without cause or by the executive officer for good reason, the Company must:

•

make a lump sum severance payment of two times the sum of his annual salary and annual cash incentive;

•

continue life, disability, accident and health insurance coverage for two years following the date of termination, except to the extent comparable benefits are provided by a new employer;

•

provide outplacement services; and

•

in certain circumstances, pay legal costs and relocation expenses associated with such termination.

        In addition, under the terms and conditions of the executive officers' equity awards, upon a change in control, they would receive full vesting of their outstanding stock options and all non-performance based RSUs and a pro-rated amount of their performance based RSUs.

        Under the executive officer's employment or severance agreements, as applicable, the amounts payable upon a change in control may be reduced under certain circumstances to the extent necessary to prevent payments to each executive officer from exceeding the limit of Section 4999 of the Internal Revenue Code of 1986, as amended (the "Code") applicable to "excess parachute payments" as defined in Section 280G of the Code. Using the Offer Price, and assuming the employment of the Company's executive officers had been terminated following a change in control of the Company by the Company without cause or by the executive officer for good reason on September 30, 2010, with no such reduction, they would have been entitled to the following payments:

Executive	Lump Sum Base+Bonus ($)		Benefits ($)		Value of Accelerated Equity Awards ($)		Total(1)
Scott Canute	$	970,000	$	288,718	$	3,157,732	$	4,416,450
Zoltan Csimma		1,299,250		289,809		848,000		2,437,059
Thomas DesRosier		1,413,250		307,166		1,370,371		3,090,787
James Geraghty		1,350,875		301,317		1,066,041		2,718,233
David P. Meeker		1,747,683		318,536		3,510,183		5,576,402
Richard Moscicki		1,510,125		272,367		1,723,352		3,505,844
Alan Smith		1,487,125		293,492		1,175,009		2,955,626
Sandford D. Smith		1,611,500		311,508		2,180,373		4,103,381
Henri A. Termeer		7,874,468		474,928		9,717,978		18,067,374
Peter Wirth		3,171,750		267,325		3,198,123		6,637,198
Michael S. Wyzga		1,653,500		310,116		3,198,123		5,161,739

(1)

The calculation of the total payment is based on the following:

•

base pay using salary as of September 30, 2010 times the applicable multiplier;

•

annual cash incentive, calculated by taking the higher of (a) the last cash incentive paid, or (b) the average of the last two cash incentives paid, times the applicable multiplier;

•

health benefits, based on 2010 COBRA rates;

•

life, accident and disability insurance premiums, based on current formula calculations;

•

outplacement services, using the maximum provided for in the agreements;

•

relocation services of $200,000, based on most recent costs paid by the Company for executive relocation; and

•

$69.00 in cash for each RSU held and for each outstanding stock option, less the applicable exercise price of such stock option.

The calculation does not include an estimate of potential legal costs associated with termination.

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        Under the employment agreements with Messrs. Termeer and Wirth, a "change in control" would be deemed to have occurred if there is a change in control of the Company of a nature that would be required to be reported in response to Item 6(e) of Schedule l4A of Regulation 14A promulgated under the Exchange Act, whether or not the Company is in fact required to comply therewith.

        Under the employment agreements with Messrs. Termeer and Wirth, and the severance agreements with Messrs. Canute, Csimma, DesRosier, Geraghty, Meeker, Moscicki, A. Smith, S. Smith and Wyzga, a "change in control" would be deemed to have occurred if:

        (A)  any person, other than the Company or its affiliate, becomes the beneficial owner, directly or indirectly, of the Company's securities representing 50% or more of the combined voting power of our then outstanding securities;

        (B)  during any period of 24 consecutive months, the individuals who at the beginning of such period constituted the Company Board or any individuals who would be continuing directors cease for any reason to constitute a majority of the Company Board;

        (C)  there is consummated a merger, share exchange or consolidation with any other company or the sale of all or substantially all of the Company's assets (each, a business combination), other than (i) a business combination that would result in the Company shareholders prior to the business combination continuing to hold a majority of the voting power of the surviving entity or (ii) a business combination effected to implement a recapitalization of the Company where no person becomes the beneficial owner of 50% or more of the voting power of the Company's then outstanding securities; or

        (D)  the Company's shareholders approve a plan of complete liquidation of the Company.

        The Offer, if consummated according to its terms, would constitute a change in control.

Director Compensation

        Only the Company's non-employee directors receive compensation for their service as directors. The non-employee directors receive the following cash compensation for their service on the Company Board and its committees: (a) an annual retainer of $40,000; (b) $2,500 for each Company Board meeting they attend; (c) $1,500 for each committee meeting they attend; (d) an annual retainer of $50,000 for service as lead director; (e) an annual retainer of $20,000 for service as audit committee chair; (f) an annual retainer of $20,000 for service as compensation committee chair; and (g) an annual retainer of $10,000 for service as the chair of the nominating and corporate governance committee, risk oversight committee and strategic planning and capital allocation committee (the "Strategic Planning Committee").

        Non-employee directors also receive equity awards for each year (or partial year) that they serve on the Company Board. Stock options and RSUs are granted automatically under the Company's 2007 Director Equity Plan on the date of each annual meeting of shareholders or, in the case of directors elected other than at an annual meeting, upon election to the Company Board. Stock options and RSUs become fully vested on the date of the next annual shareholders meeting following the date of grant, provided the director is an active member of the Company Board at the opening of business on that date. Each stock option grant has an exercise price equal to the closing price of a Share on the date of grant and a term of ten years. RSUs are valued on the date of grant based on the closing price of a Share. The plan provides for acceleration of all unvested awards in the event of a change in control of the Company. The plan provides for an annual grant to each non-employee director of (1) stock options to purchase 7,125 Shares, and (2) RSUs for 2,375 Shares.

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Indemnification of Executive Officers and Directors

        Section 2.02(b)(4) of the Massachusetts Business Corporation Act (the "MBCA") provides that a corporation may, in its articles of organization, eliminate or limit a director's personal liability to the corporation for monetary damages for breaches of fiduciary duty as a director, except in circumstances involving (1) a breach of the director's duty of loyalty to the corporation or its shareholders, (2) acts or omissions not in good faith or which involve intentional misconduct or a knowing violation of law, (3) improper distributions, and (4) transactions from which the director derived an improper personal benefit. Section VI.C.3. of the Company's Articles of Organization provides that no director shall be liable to the Company or its shareholders for monetary damages for any breach of fiduciary duty as a director, except to the extent that the elimination or limitation of liability is not permitted under Massachusetts corporation law, as in effect when such liability is determined, and that no amendment or repeal of that provision shall deprive a director of the benefits thereof with respect to any act or omission occurring prior to such amendment or repeal.

        Section 8.51 of the MBCA permits the Company to indemnify a director if the individual (1) acted in good faith, (2) reasonably believed that his or her conduct was (a) in the best interests of the Company or (b) at least not opposed to the best interest of the Company, and (3) in the case of a criminal proceeding, had no reasonable cause to believe his or her conduct was unlawful. Section 8.51 also permits the Company to indemnify a director for conduct for which such individual is or would be exculpated under the provision in the articles of organization referred to above, whether or not the director satisfied a particular standard of conduct. Section 8.56 of the MBCA permits the Company to indemnify an officer (1) under those circumstances in which the Company would be allowed to indemnify a director and (2) to such further extent as the Company chooses, provided that the liability does not arise out of acts or omissions not in good faith or which involve intentional misconduct or a knowing violation of law. This broader permissible indemnification for officers also is available for a director who is an officer if the individual becomes party to a proceeding on the basis of an act or omission solely as an officer. Section 8.55 of the MBCA mandates that the determination that an award of indemnification is appropriate in a particular circumstance be made by (1) a majority vote of all disinterested directors or a majority of a committee of disinterested directors (in each case, if there are at least two disinterested directors), (2) special legal counsel, or (3) the shareholders.

        Prior to the final disposition of a proceeding involving a director or officer, Sections 8.53 and 8.56 of the MBCA allow the Company to pay for or reimburse reasonable expenses. As a condition, the director or officer must deliver a written undertaking to repay the funds if the individual is determined not to have met the relevant standard of conduct, which determination is made in the same manner as the determination of whether an individual is entitled to indemnification. This undertaking may be accepted without security and without regard to the individual's financial ability to make repayment. Another condition to advancement of expenses is that the individual submit a written affirmation of his or her good faith that he or she has met the standard of conduct necessary for indemnification (or that the matter involved conduct for which liability has been eliminated pursuant to the charter exculpation provision referred to above).

        The MBCA allows a corporation to obligate itself (1) to indemnify a director or officer and (2) to provide advancement of expenses to such an individual. Such a commitment may be made in the corporation's articles of organization or by-laws or in a resolution adopted, or a contract approved, by the board of directors or the shareholders. Article VI of the Company's by-laws provides that the Company shall indemnify its directors and officers to the fullest extent permitted by law, and may indemnify such other employees as identified by the Company Board. In addition, the Company has in place agreements with directors and officers that affirm this obligation to indemnify such individuals to the fullest extent permitted by law and also contractually commit the Company to provide advancement of expenses to the fullest extent permitted by law. These indemnification agreements also contain procedural provisions as well as protections in the event of a change of control.

13

        Sections 8.52 and 8.56(c) of the MBCA mandate indemnification for reasonable expenses, regardless of whether an individual has met a particular standard of conduct, in connection with proceedings in which a director or officer is wholly successful, on the merits or otherwise. Furthermore, Section 8.54 of the MBCA provides that a court may direct a corporation to indemnify a director or officer if the court determines that (1) the director or officer is entitled to mandatory indemnification under the MBCA, (2) the director or officer is entitled to indemnification pursuant to a provision in the corporation's articles of organization or by-laws or in a contract or a board or shareholder resolution, or (3) it is fair and reasonable to indemnify the director or officer, regardless of whether he or she met the relevant standard of conduct.

        In addition to covering directors and officers of the Company if they become parties to legal proceedings when acting in such capacities, the Company's by-laws and indemnification agreements, as permitted by the MBCA, also cover such individuals when serving at the Company's request for another entity, specifically, as a director, officer, partner, trustee, employee, or agent of another domestic or foreign corporation, partnership, joint venture, trust, employee benefit plan, or other entity. A director or officer is considered to be serving an employee benefit plan at the request of the Company if the individual's duties to the Company also impose duties on, or otherwise involve services by, the director or officer to the plan or to the participants in or beneficiaries of the plan.

        The Company maintains directors' and officers' liability insurance which may protect the Company's directors and officers against costs and liabilities imposed upon them in their roles with the Company, including in circumstances under which indemnification would not be permitted under the MBCA.

Shareholder Derivative Actions

        In December 2009, two actions were filed by shareholders derivatively for Genzyme's benefit in the U.S. District Court for the District of Massachusetts against certain executive officers and the following members of the Company Board: Douglas A. Berthiaume, Robert J. Bertolini, Gail K. Boudreaux, Robert J. Carpenter, Charles L. Cooney, Victor J. Dzau, Senator Connie Mack III, Richard F. Syron, and Henri A. Termeer. These actions were filed after a ninety day period following their respective demand letters had elapsed (the "District Court Actions"). In January 2010, a derivative action was filed in Massachusetts Superior Court (Middlesex County) by a shareholder who has not issued a demand letter, and in February and March 2010, two additional derivative actions were filed in Massachusetts Superior Court (Suffolk County and Middlesex County, respectively) by two separate shareholders after the lapse of a ninety day period following the shareholders' respective demand letters (collectively, the "State Court Actions").

        The derivative actions in general are based on allegations that the Company Board and certain executive officers breached their fiduciary duties by causing the Company to make purportedly false and misleading or inadequate disclosures of information regarding manufacturing issues, compliance with Good Manufacturing Practices, ability to meet product demand, expected revenue growth, and approval of Lumizyme. The actions also allege that certain of the Company's directors and executive officers took advantage of their knowledge of material non-public information about the Company to illegally sell Shares they personally held. The plaintiffs generally seek, among other things, judgment in favor of the Company for the amount of damages sustained by the Company as a result of the alleged breaches of fiduciary duty, disgorgement to the Company of proceeds that certain of our directors and executive officers received from sales of Shares and all proceeds derived from their service as directors or executives of the Company, and reimbursement of plaintiffs' costs, including attorneys' and experts' fees. The District Court Actions have been consolidated in In Re Genzyme Derivative Litigation, and the plaintiffs have agreed to a joint stipulation staying these cases until the Company Board has had sufficient time to exercise its duties and complete an appropriate investigation, which is ongoing. On July 9, 2010, one of the State Court Actions was dismissed without prejudice for plaintiffs' failure to serve process on the defendants. The Massachusetts Superior Court (Middlesex County) also ordered

14

transfer and consolidation of the remaining two State Court Actions in the Suffolk Superior Court Business Litigation Session. The court has indicated that discovery in that action also will be stayed for some period pending the Company Board's completion of its ongoing investigation in response to the shareholders demand.

        Under Massachusetts law, only a shareholder may maintain a derivative action. Accordingly, shareholders who sell shares in the Offer would cease to have standing as plaintiffs in the derivative cases. In addition, if the Proposed Merger were to close, the derivative claims would be extinguished, as Offeror was not a shareholder at the time of the actions and omissions alleged in the derivative actions.

Recent Additions to the Company Board

        On December 8, 2009, the Company Board appointed Robert J. Bertolini as director. Mr. Bertolini served as executive vice president and chief financial officer at Schering-Plough from late 2003 until its merger with Merck in late 2009.

        On April 14, 2010, the Company entered into an amended and restated agreement (the "Amended Relational Agreement") with Relational Investors LLC ("Relational"), Ralph V. Whitworth, and certain other Relational affiliates (the "Relational Group"), replacing and superseding the letter agreement dated January 6, 2010 between the parties. Mr. Whitworth is a principal and co-founder of Relational. Under the Amended Relational Agreement, the Company agreed, effective as of the date of the Amended Relational Agreement, to appoint Mr. Whitworth to the Company Board, to appoint Mr. Whitworth to the Compensation Committee and Nominating and Corporate Governance Committee of the Company Board, and to establish the Strategic Planning Committee of the Company Board that Mr. Whitworth chairs. The Company also committed to nominate and recommend that the Company's shareholders vote for the election of Mr. Whitworth at the Company's 2011 annual meeting of shareholders. The Amended Relational Agreement also provided that the Company would appoint to the Company Board an additional independent director with expertise in pharmaceutical or biologics manufacturing or quality control operations upon recommendation of the Relational Group. The foregoing description of the Amended Relational Agreement does not purport to be complete and is qualified in its entirety by reference to the Amended Relational Agreement, a copy of which is filed as Exhibit (e)(2) to this Schedule 14D-9 and is incorporated herein by reference.

        On June 7, 2010, the Company announced that Dennis M. Fenton had been nominated for election to the Company Board. Mr. Fenton was elected to serve as a director at the Company's 2010 annual meeting of shareholders held on June 16, 2010. The addition of Mr. Fenton, who had served as executive vice president of operations at Amgen Inc. and established much of the biologics operating protocol that is standard practice in the biotechnology industry, fulfilled a commitment the Company had made as part of the Amended Relational Agreement.

        On June 9, 2010, the Company entered into an agreement (the "Icahn Agreement") with Icahn Partners LP, Icahn Partners Master Fund LP, Icahn Partners Master Fund II L.P., Icahn Partners Master Fund III L.P. and High River Limited Partnership (collectively, the "Icahn Group") to settle a proxy contest relating to the Company's 2010 annual meeting of shareholders. The Icahn Group had previously engaged in a proxy contest relating to the Company's 2010 annual meeting of shareholders, nominating their own slate of four nominees for election to the Company Board. Under the Icahn Agreement, the Icahn Group irrevocably withdrew their notice of intention to nominate certain individuals for election as directors at the Company's 2010 annual meeting of shareholders, and the Company agreed that, within one business day after the 2010 annual meeting of shareholders, the number of seats on the Company Board would be increased by two, and two individuals associated with the Icahn Group, Dr. Steven Burakoff, who was on the originally proposed Icahn Group slate, and Dr. Eric Ende, would be appointed to serve as directors until the Company's 2011 annual meeting of shareholders. The foregoing description of the Icahn Agreement does not purport to be complete and

15

is qualified in its entirety by reference to the Icahn Agreement, a copy of which is filed as Exhibit (e)(3) to this Schedule 14D-9 and is incorporated herein by reference.

(b)   Arrangements with Offeror and Sanofi.

        In connection with its acquisition of oncology products from Bayer Schering Pharma AG ("Bayer"), the Company assumed a License, Development and Commercialization Agreement, dated as of September 7, 2006 (the "License Agreement"), between Bayer and Xanthus Pharmaceuticals, Inc. ("Xanthus"), and a Commercial Supply Agreement, dated as of January 20, 2009 (the "Supply Agreement"), between Bayer and Xanthus. The License Agreement includes a license to commercialize oral fludarabine in the U.S. and the Supply Agreement includes an obligation for the Company to supply oral fludarabine for sale in the U.S. In 2008, Xanthus was acquired by Antisoma plc, who subsequently sold and assigned the U.S. rights to oral fludarabine to Sanofi in 2009. As a result, the Company and Sanofi have a contractual relationship pursuant to the License Agreement and the Supply Agreement. Sanofi markets and sells oral fludarabine in the U.S. under the trade name Oforta. The Company retains the rights to oral fludarabine outside of the U.S. and all other forms of fludarabine worldwide.

        In connection with the License Agreement, Sanofi has incurred obligations to make estimated royalty payments to the Company of approximately $170,868 on sales of oral fludarabine in the U.S., beginning in January 2010 through September 30, 2010. In connection with the Supply Agreement, Sanofi has incurred obligations to make estimated payments of approximately $638,034 to the Company for supplies of oral fludarabine, beginning in the fourth quarter of 2009 through September 30, 2010.

        The Company and Sanofi have disputed certain rights and obligations of the parties at times or from time to time during the relationship. However, the License Agreement and the Supply Agreement remain in full force and effect.

        Also in connection with its acquisition of oncology products from Bayer in 2009, the Company assumed the responsibilities and obligations from Bayer for a Scientific Collaboration and License Agreement and related agreements. Under these agreements, in exchange for a license to commercialize Leukine, the Company was obligated to pay royalties to Sanofi in an amount equal to between 5.0% and 7.5% of net sales of Leukine. Since May 2009, the Company has paid Sanofi approximately $4.1 million under the agreements. The Company believes that its royalty payment obligations under these agreements expired in July 2010 and has notified Sanofi of its position.

        In connection with the Company's acquisition of Sangstat Medical Corporation in 2003, the Company assumed a Manufacturing Services Agreement, two Building Lease Agreements and a Site Services Agreement, all relating to the Company's manufacture of Thymoglobulin and Lymphoglobuline. Under the Manufacturing Services Agreement, Sanofi provides the Company quality control laboratory services and supplies certain manufacturing materials. During the past two years, the Company has paid Sanofi approximately $1.7 million under the Manufacturing Services Agreement. Under the Building Lease Agreements, the Company leases from Sanofi two buildings used for manufacturing, testing and administrative activities. During the past two years, the Company has paid Sanofi approximately $1.8 million under the Building Lease Agreements. Under the Site Services Agreement, Sanofi provides the Company with utility, maintenance and administrative services for the leased buildings. During the past two years, the Company has paid Sanofi approximately $2.2 million under the Site Services Agreement.

        According to the Schedule TO, Sanofi beneficially owns 100 Shares, acquired in a brokerage transaction on September 1, 2010, at a price per Share of $70.52. According to the Schedule TO, Offeror does not own any Shares.

16

Item 4.    The Solicitation or Recommendation.

(a)   Recommendation of the Company Board of Directors.

        After consideration, including review of the terms and conditions of the Offer in consultation with the Company's management, as well as the Company's financial and legal advisors, the full Company Board, by unanimous vote, at a meeting held on October 7, 2010, determined that the Offer is inadequate and that the Offer is not in the best interests of the Company.

Accordingly, for the reasons described in more detail below, the Company Board unanimously recommends that the Company's shareholders reject the Offer and NOT tender their Shares to Offeror pursuant to the Offer.

        If you have tendered your Shares, you can withdraw them. For assistance in withdrawing your Shares, you can contact your broker or the Company's information agent, Innisfree M&A Incorporated ("Innisfree"), at the contact information below.

Innisfree M&A Incorporated
501 Madison Avenue, 20th Floor
New York, NY 10022
Shareholders May Call Toll-Free: (888) 750-5835
Banks & Brokers May Call Collect: (212) 750-5833

        In reaching the conclusions and in making the recommendation described above, the Company Board took into account a number of reasons, described under "Reasons for the Recommendation of the Company Board" below.

        Copies of the Company's press release and a letter to the Company's shareholders relating to the recommendation of the Company Board to reject the Offer are filed as Exhibit (a)(1) and Exhibit (a)(2) hereto respectively and are incorporated herein by reference.

(b)   Background and Reasons for the Recommendation of the Company Board.

Background of the Offer

        Prior to the Company's 2010 annual meeting of shareholders, while the Company was involved in a proxy contest with certain funds affiliated with the Icahn Group, the Company's Chief Executive, Henri Termeer, received a call from Christopher Viehbacher, Chief Executive Officer of Sanofi. Mr. Viehbacher expressed to Mr. Termeer his support for the Company during the proxy contest, offered assistance and indicated some interest in some type of strategic transaction between the Company and Sanofi. Mr. Termeer responded that the Company could potentially be open to a strategic partnership along the lines of a "Roche/Genentech" arrangement, but was focused on the proxy contest and asked Mr. Viehbacher to follow up at a later time after the Company's annual meeting.

        On June 9, 2010, the Company announced an agreement to settle its proxy contest with the Icahn Group. Thereafter, on June 16, 2010, the Company held its annual meeting of shareholders. During an executive session of the Company Board following the annual meeting, Mr. Termeer informed the members of the Company Board of the call that he had received from Mr. Viehbacher expressing Sanofi's support of the Company and its indication of interest in some kind of transaction involving the Company.

        During the week of June 28, 2010, Mr. Viehbacher called Mr. Termeer to convey Sanofi's interest in a potential acquisition of the Company. Mr. Viehbacher asked Mr. Termeer whether he would be willing to meet in mid-July during a pharmaceutical conference that both executives were scheduled to attend. Mr. Termeer indicated that he would have to get back to Mr. Viehbacher regarding the proposed meeting.

17

        After the call with Mr. Viehbacher, Mr. Termeer informed Peter Wirth, the Company's Executive Vice President of Legal and Corporate Development, and Michael Wyzga, the Company's Executive Vice President and Chief Financial Officer, of the substance of his call with Mr. Viehbacher. On June 30 and July 1, Messrs. Termeer, Wirth and Wyzga reached out to members of the Strategic Planning Committee to inform them of Sanofi's indication of interest.

        After market rumors surfaced on July 2, 2010, indicating that Sanofi was interested in a potential large acquisition in the United States, Mr. Termeer and Mr. Wirth contacted representatives of Goldman, Sachs & Co. ("Goldman Sachs"), to schedule a call on July 4, 2010 to discuss the market rumors with representatives of Credit Suisse Securities (USA) LLC ("Credit Suisse") and Goldman Sachs, who had both served as financial advisors to the Company during the proxy contest with the Icahn Group, and also are currently advising the Company in connection with its proposed sale of its Genetic testing business and its exploration of strategic alternatives for its Diagnostic products business. During the July 4 call, Mr. Termeer and Mr. Wirth asked Credit Suisse and Goldman Sachs to prepare presentations on a potential transaction involving the Company and Sanofi and other strategic options potentially available to the Company, which were to be delivered to the Strategic Planning Committee at its next scheduled meeting on July 9, 2010.

        On July 6, 2010, Mr. Termeer and Mr. Wirth again spoke with representatives of Credit Suisse and Goldman Sachs. During this call, the parties discussed the market rumors as well as the presentation that Credit Suisse and Goldman Sachs would give to the Strategic Planning Committee at its upcoming meeting. The Company asked Credit Suisse and Goldman Sachs to participate in the Company's discussions and to prepare presentations because of their past work and experience with the Company in connection with the proxy contest.

        At the July 9, 2010 meeting of the Strategic Planning Committee, presentations were made by Credit Suisse and Goldman Sachs. After discussion, the Strategic Planning Committee concluded that, due to the Company's depressed share price as a result of manufacturing difficulties over the past year as well as the Company's progress towards fixing its manufacturing issues, cost and capital efficiency initiatives, and the outlook for its new product pipeline, the likelihood of consummating a transaction at a price that would accurately reflect the Company's intrinsic value and be attractive to the Company's shareholders was not great. The Strategic Planning Committee concluded that it was not an appropriate time for the Company to pursue a transaction. The Strategic Planning Committee therefore directed Mr. Termeer to decline Mr. Viehbacher's invitation to meet in mid-July. On July 10, 2010, Mr. Termeer called Mr. Viehbacher, explained the Company's position and declined his invitation to meet to discuss a possible transaction.

        On July 23, 2010, certain press outlets, including Bloomberg News and The Wall Street Journal, reported that Sanofi had made an informal acquisition approach to the Company. Later that day, in response to these market reports, the Company held a special meeting of the Company Board to discuss the rumors, during which Mr. Termeer updated the Company Board on the status of his communications with Sanofi.

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        On July 29, 2010, Mr. Viehbacher called Mr. Termeer to inform him that Sanofi would be sending a letter later that day to propose an acquisition of the Company. Later that day, Sanofi sent a non-binding proposal for an acquisition of the Company at a price of $69.00 per Share. The text of that letter is set forth below:

July 29, 2010

VIA DHL AND TELECOPIER
Mr. Henri A. Termeer
Chairman, President and Chief Executive Officer
Genzyme Corporation
500 Kendall Street
Cambridge, Massachusetts 02142
USA

Dear Henri:

As I articulated to you during several conversations, Sanofi-Aventis ("Sanofi-Aventis") has carefully studied a potential acquisition of Genzyme Corporation ("Genzyme"), and believes that it represents a compelling opportunity for Genzyme, Sanofi-Aventis and our respective shareholders. In light of that, I am writing this letter to layout our proposal to you and your Board.

Genzyme has historically been a true success story in biotech, and the company has become the world leader in providing novel treatments for genetic diseases. In addition, the company built a positive reputation within the scientific community and developed strong relationships with patient advocacy groups, physicians, patients and the broader healthcare community. However, the company now faces a number of significant and well-documented challenges that were discussed thoroughly during this year's proxy campaign. An acquisition by Sanofi-Aventis would not only position the company to overcome these challenges quickly and successfully by applying Sanofi-Aventis' global resources and expertise to help realize and accelerate Genzyme's business strategy, but also deliver near-term compelling value to your shareholders that takes into account the company's future upside potential.

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The proposed transaction would provide several key benefits to Genzyme, its shareholders, employees and the patients and physicians it serves:

•

Acceleration of Genzyme Vision: Sanofi-Aventis would put its full resources behind Genzyme to invest in developing new treatments, enhance penetration in existing markets and further expand into emerging markets. Genzyme would be able to leverage Sanofi-Aventis' strong global footprint and its manufacturing expertise in order to address Genzyme's manufacturing issues.

•

Center of Excellence: Sanofi-Aventis already recognizes the strategic importance of the greater Boston area as evidenced by the establishment of Sanofi-Aventis' oncology and vaccines research units in Cambridge. Genzyme would become the global center for excellence for Sanofi-Aventis in orphan diseases and further increase Sanofi-Aventis' presence in the greater Boston area.

•

Continuation of Genzyme legacy within Sanofi-Aventis: Genzyme's orphan disease business would be managed as a stand-alone division under the Genzyme brand, with its own R&D, manufacturing and commercial infrastructure, similar to how Sanofi-Aventis has handled other recent transactions. Genzyme's management and employees would play a key role within Sanofi-Aventis following the acquisition.

•

All-cash offer: The purchase price would be paid in cash, offering immediate and certain value for Genzyme's shareholders. Our offer is not subject to a financing contingency.

•

Substantial premium: We are prepared to pay $69 for each of the issued and outstanding common shares of Genzyme. This is a premium of 38.4% over the share price as of July 1, 2010, the day prior to press speculation regarding Sanofi-Aventis' potential acquisition plans for a large U.S. biotech company. It also represents a premium of 30.9% over the one month historical average share price through July 22, 2010, the day prior to press speculation that Sanofi-Aventis had made an approach to acquire Genzyme.

In addition to these compelling reasons, we believe there are many others that demonstrate why Sanofi-Aventis is the right partner for Genzyme. Sanofi-Aventis has significant expertise executing and integrating transactions, and a strong track record creating value through those transactions by enhancing their performance through leveraging Sanofi-Aventis' capabilities. Sanofi-Aventis has demonstrated that it is a good corporate partner by enabling its affiliates to maintain their distinctive culture and focus on their core strengths. Sanofi-Aventis is strong financially with a market capitalization of approximately $77 billion, revenue of approximately $38 billion and EBITDA of approximately $16 billion. From Sanofi-Aventis' perspective, the proposed transaction would provide a new sustainable growth platform.

The Board of Directors of Sanofi-Aventis supports this proposal for an acquisition of Genzyme. Consummation of the proposed acquisition would be subject to satisfactory completion of confirmatory due diligence, board approvals, execution of a merger agreement and the satisfaction of customary conditions to closing.

We have completed an extensive analysis of Genzyme and have carefully considered the proposed transaction based on publicly available information. We have engaged Evercore Partners and J.P. Morgan as financial advisors and Weil Gotshal as legal counsel. In order to come to an agreement expeditiously, we are prepared to begin our confirmatory due diligence immediately and are confident that we can complete our review within three weeks.

We expect that we and our advisors would negotiate and finalize the terms of a merger agreement relating to the proposed transaction within this same period of time. We have completed a preliminary competition review relating to our two companies with the assistance of our outside antitrust counsel and we believe that the transaction would receive all necessary regulatory approvals and that it could close expeditiously.

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This letter and the terms or our proposal are confidential and should not be disclosed publicly or to any third party without our prior written consent, other than to the Board of Directors of Genzyme and to Genzyme's advisors for the purpose of evaluating the proposal. Should a public disclosure become required by law or regulation, we request that you inform us of such and, to the extent lawful, consult with us on the content of any public disclosure you intend to make.

This letter constitutes a bona fide, non-binding proposal to acquire all of the outstanding shares of Genzyme. This letter does not create or constitute any legally binding obligation, liability or commitment by Sanofi-Aventis or any of our affiliates regarding the proposed transaction and there will be no legally binding agreement between us unless and until a definitive agreement is executed by Genzyme and Sanofi-Aventis.

We believe our offer is compelling to your shareholders and that our capabilities and investment in your business would bring real enhancements to all of your stakeholders. In addition, Sanofi-Aventis is uniquely well positioned to help you address the manufacturing and other challenges faced by Genzyme, and we therefore believe that it is important for you to further explore this transaction.

I am ready to meet with you in person to discuss this matter in detail at any time and I look forward to hearing back from you shortly.

Yours sincerely,
Sanofi-Aventis

By: Christopher A. Viehbacher
      Chief Executive Officer

        After receipt of this proposal, the Company convened a meeting of its Strategic Planning Committee to discuss the letter and Sanofi's proposal. Representatives from Credit Suisse, Goldman Sachs, and the Company's legal advisor, Ropes & Gray LLP ("Ropes & Gray"), attended this meeting.

        Thereafter, on August 2, 2010, the Company held a meeting of the full Company Board to walk the directors through Sanofi's proposal, discuss a preliminary response and make plans to compile data and undertake analysis in connection with preparing a formal response. Representatives from Credit Suisse, Goldman Sachs, and Ropes & Gray, also attended this meeting. During the meeting, a representative from Ropes & Gray described the directors' fiduciary duties under Massachusetts corporation law in determining the Company's response.

        Following this meeting, Mr. Termeer sent a letter to Mr. Viehbacher. The text of that letter is set forth below:

August 2, 2010

Mr. Christopher A. Viehbacher
Chief Executive Officer
Sanofi-Aventis
174, avenue de France
75635 Paris, Cedex 13

Dear Chris,

As I promised last week, I am getting back to you today regarding your letter of July 29, 2010. We have reviewed the contents of the letter with the Genzyme Board of Directors. The Board has authorized our financial and legal advisors to assist them in evaluating your unsolicited, non-binding proposal. After

21

Genzyme's Board of Directors has reviewed and considered our advisors' analysis, I will contact you with our response.

Sincerely,

Henri A. Termeer
Chairman and CEO

        On August 3, 2010, representatives of Credit Suisse and Goldman Sachs spoke on the telephone with representatives of Evercore Partners ("Evercore") and JPMorgan Chase & Co. ("JPMorgan"), who were acting as financial advisors to Sanofi. During this call, Sanofi's advisors requested that the Company permit Evercore and JPMorgan to perform due diligence on the Company in connection with Sanofi's proposal. Credit Suisse and Goldman Sachs indicated that they would get back to Sanofi on whether Evercore and JPMorgan would be permitted access to the Company to perform the requested due diligence.

        On August 10, 2010, the Company held a meeting of the full Company Board to discuss the Company's response to Sanofi's July 29 letter. At this meeting, representatives of Credit Suisse and Goldman Sachs gave a presentation to the directors containing their financial analyses of the proposal and also reviewed the other strategic options potentially available to the Company and discussed a strategy for interacting with Sanofi. A representative from Ropes & Gray also provided legal advice with respect to responding to the proposal and aspects of Massachusetts corporation law. After discussion, the Company Board unanimously concluded that Sanofi's proposal materially undervalued the Company, was not in the best interest of the Company and its shareholders, and directed that the proposal be rejected.

        On August 11, 2010, the Company sent a letter stating that the Company Board had unanimously rejected Sanofi's proposal. The text of that letter is set forth below:

August 11, 2010

Mr. Christopher A. Viehbacher
Chief Executive Officer
Sanofi-Aventis
174, avenue de France
75635 Paris, Cedex 13

Dear Chris,

As I promised in my August 2 letter, the Genzyme Board of Directors reviewed your unsolicited, non-binding $69.00 per share proposal to acquire Genzyme. With the assistance of our financial and legal advisors, the Board unanimously rejected your offer. Without exception, each member of the Genzyme Board believes that this is not the right time to sell the Company because your opportunistic takeover proposal does not begin to recognize the significant process underway to rectify our manufacturing challenges or the potential for our new product pipeline.

We recognize that Genzyme's share price has been depressed as a result of manufacturing setbacks the Company experienced last year. In reaching a decision to reject your offer, the Board not only reviewed the timeline and remaining steps necessary to address the manufacturing challenges, but also the potential of our new product pipeline, in particular the outlook for our MS treatment Alemtuzumab. We are confident that these factors coupled with our newly announced discipline for deploying capital and significant opportunity to reduce costs will soon be recognized by investors.

The Board is resolute about maximizing Genzyme's future value for our shareholders.

Sincerely,

Henri Termeer

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        On August 16, 2010, Credit Suisse and Goldman Sachs spoke with Mr. Termeer and Mr. Wirth on the telephone to discuss potential alternatives for the Company. Mr. Wirth and Mr. Termeer asked the bankers to present their analysis during a meeting of the Strategic Planning Committee the next day. Credit Suisse and Goldman Sachs made this presentation to the Strategic Planning Committee on August 17, 2010 and, on August 18, 2010, provided the full Company Board with the same analysis of the Company's possible strategic options. At the August 18 meeting, the full Company Board discussed the Company's general strategy moving forward. Additionally, on August 18, the independent directors of the Company Board, which includes all directors except Mr. Termeer, met and decided to retain legal counsel for the independent directors.

        On August 20, 2010, representatives of Credit Suisse and Goldman Sachs spoke on the telephone with Sanofi's financial advisors to set up a possible meeting with Evercore and JPMorgan during which Credit Suisse and Goldman Sachs could discuss important and non-public information regarding aspects of the Company's business and strategy that might help Sanofi better understand the value of the Company. During this discussion, Credit Suisse and Goldman Sachs set forth certain confidentiality conditions that the Company would impose upon Sanofi's receipt of this information. These arrangements, including restrictions on trading Shares, were further refined in discussions among counsel.

        On August 24, 2010, Credit Suisse and Goldman Sachs met with Evercore and JPMorgan to share important and non-public information on the Company's ongoing manufacturing recovery, its Value Improvement Program Initiative and previously undisclosed clinical data on alemtuzumab for multiple sclerosis.

        On August 29, 2010, Mr. Viehbacher called Mr. Termeer to inform him that Sanofi was sending another letter to Mr. Termeer. This letter reiterated Sanofi's proposal to acquire all outstanding Shares at $69.00 per Share. Sanofi made this letter public through a press release. The text of this letter is set forth below:

August 29, 2010

VIA EMAIL, TELECOPIER AND DHL
Mr. Henri A. Termeer
Chairman, President and Chief Executive Officer
Genzyme Corporation
500 Kendall Street
Cambridge, Massachusetts 02142
USA

Dear Henri:

As you are aware, I have been trying to engage with you regarding a potential acquisition for the past few months. As a consequence of your unwillingness even to meet with us, we sent you a detailed, written proposal on July 29, 2010. We believe that this proposal to acquire all of the issued and outstanding shares of Genzyme for $69.00 per share in cash is compelling for Genzyme's shareholders and represents substantial value for them.

We are disappointed that you rejected our proposal on August 11 without discussing its substance with us. After our repeated requests, you agreed only to let our respective financial advisors hold a meeting of limited scope. Our financial advisors finally met briefly on August 24, but the meeting simply served as further confirmation that as throughout you remain unwilling to have constructive discussions. As I have mentioned to you, we are committed to a transaction with Genzyme, and, therefore, we feel we are left with no choice but to take our compelling proposal directly to your shareholders by making its terms public.

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Sanofi-Aventis' fully-financed, all-cash offer to acquire all of the issued and outstanding shares of Genzyme's common stock for $69.00 per share represents a very significant premium of 38% over Genzyme's unaffected share price of $49.86 on July 1, 2010. Our offer also represents a premium of almost 31% over the one-month historical average share price through July 22, 2010, the day prior to press speculation that Sanofi-Aventis had made an approach to acquire Genzyme. Based on the analysts' consensus estimates, this represents a multiple of 36 times 2010 EPS and 20 times 2011 EPS, which takes into account the expected recovery of Genzyme's performance in 2011.

We believe that now is the right time for you and the Genzyme Board to consider a potential transaction that maximizes value for Genzyme's shareholders. Genzyme has underperformed its peers for a number of years. It continues to face several significant and well-documented challenges that were discussed thoroughly during this year's proxy campaign, and which Genzyme recently disclosed will take three to four years to resolve. An acquisition by Sanofi-Aventis would not only position Genzyme to overcome these challenges quickly and successfully by applying Sanofi-Aventis' global resources and expertise to help realize Genzyme's business strategy, but also deliver near-term compelling value to Genzyme's shareholders that takes into account the company's future upside potential.

As I explained in my July 29 letter, the proposed transaction would provide several key benefits to Genzyme, its shareholders, employees and the patients and physicians it serves, including:

•

Achievement of Genzyme's Vision: Sanofi-Aventis would put its full resources behind Genzyme to invest in developing new treatments, enhance penetration in existing markets and further expand into emerging markets. Genzyme would be able to leverage Sanofi-Aventis' strong global footprint and its manufacturing expertise in order to address Genzyme's manufacturing issues.

•

Center of Excellence: Sanofi-Aventis already recognizes the strategic importance of the greater Boston area as evidenced by the establishment of Sanofi-Aventis' oncology and vaccines research units in Cambridge. Genzyme would become the global center for excellence for Sanofi-Aventis in rare diseases and further increase Sanofi-Aventis' presence in the greater Boston area.

•

Continuation of Genzyme's Legacy within Sanofi-Aventis: Genzyme's rare disease business would be managed as a stand-alone division under the Genzyme brand, with its own R&D, manufacturing and commercial infrastructure, similar to how Sanofi-Aventis has handled other recent transactions. Genzyme's management and employees would play a key role within Sanofi-Aventis following the acquisition.

•

Fully Financed, All-Cash Premium Offer: The purchase price would be paid in cash, offering immediate, substantial and certain value for Genzyme's shareholders. Our offer is fully financed and is not subject to a financing contingency.

As I indicated in my July 29 letter to you, in addition to these compelling reasons, we believe there are many others that demonstrate why Sanofi-Aventis is the right partner for Genzyme. Sanofi-Aventis has significant expertise executing and integrating acquisitions, and a strong track record of creating value through those acquisitions by enhancing their performance through leveraging Sanofi-Aventis' capabilities. Sanofi-Aventis has demonstrated that it is a good corporate partner by enabling its affiliates to maintain their distinctive culture and focus on their core strengths. Sanofi-Aventis is strong financially with a market capitalization of approximately $75 billion, annual revenue of approximately $38 billion and annual EBITDA of approximately $16 billion. From Sanofi-Aventis' perspective, the proposed transaction would provide a new sustainable growth platform.

It is our preference to work together with you and the Genzyme Board to reach a mutually agreeable transaction. As we have consistently stated, we place value on the ability to engage in a constructive dialogue and to conclude a successful outcome that would ensure a timely and smooth integration.

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We have engaged and have been working closely with Evercore Partners and J.P. Morgan, as lead financial advisors, and Weil, Gotshal, as legal counsel. As explained in my July 29 letter, we have completed an extensive analysis of Genzyme and have carefully considered the proposed transaction on the basis of publicly available information. We do not believe that there are any regulatory or other impediments to consummation of the proposed transaction. We could complete our confirmatory due diligence and finalize the terms of a transaction in a two-week period.

Sanofi-Aventis is committed to a transaction with Genzyme. Given the substantial value represented by our offer and the other compelling benefits of a transaction, we are confident that Genzyme's shareholders will support our proposal. We have taken the step of making this letter public, so as to explain directly to your shareholders our proposal, our actions and our commitment. Your continued refusal to enter into constructive discussions will serve only to further delay the ability of your shareholders to receive the substantial value represented by our all-cash offer. We therefore are prepared to consider all alternatives to complete this transaction. Our team and advisors are ready to meet with you and your team immediately to discuss our proposal and to move things forward expeditiously.

Yours sincerely,

Sanofi-Aventis

By: Christopher A. Viehbacher
      Chief Executive Officer

cc: Board of Directors, Genzyme Corporation

        After receiving this letter, Mr. Termeer convened conference calls with Mr. Wirth, Mr. Wyzga and representatives of Credit Suisse, Goldman Sachs and Ropes & Gray. Mr. Wirth informed each Company director of the letter and arranged for a meeting of the Company Board to determine the Company's response. At a meeting of the Company Board that afternoon, the Company Board discussed the renewed proposal and concluded that it provided no new information and no improvement on price. Accordingly, the Company Board unanimously reaffirmed its rejection of Sanofi's $69.00 proposal and authorized the Company to communicate that rejection to Sanofi and issue the following press release:

Genzyme Confirms Receipt of Unsolicited Proposal

CAMBRIDGE, Mass.—(BUSINESS WIRE)—Genzyme Corp. (NASDAQ: GENZ) today confirmed that it has received an unsolicited, non-binding proposal from Sanofi-Aventis to acquire all the outstanding shares of Genzyme for $69 per share in cash. The Genzyme board of directors met last night, unanimously affirmed its previous rejection of Sanofi's proposal, and instructed the company to send Sanofi the following response letter:

Dear Mr. Viehbacher:

The Genzyme board is now in receipt of your second unsolicited letter proposing to acquire the company for $69 per share in cash. This letter, received yesterday, is identical to last month's offer. It provides no new information and no improvement in price, and therefore fails to establish a basis for engagement by the Genzyme board.

This should come as no surprise to Sanofi. On August 11, 2010, Genzyme responded to your first letter dated July 29, 2010. In our response, we stated that, "without exception, each member of the Genzyme board believes this is not the right time to sell the company, because your opportunistic takeover proposal does not begin to recognize the significant progress underway to rectify our manufacturing challenges or the potential for our new-product pipeline." Our board met last evening in response to your second letter and unanimously confirmed those views.

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As you are well aware, our bankers met with your financial advisors on August 24, 2010, and provided very useful, non-public information regarding progress the company has made to meaningfully improve its manufacturing capacity, the tremendous future upside of our multiple sclerosis drug alemtuzumab, and our outlook for significant cost reductions that will further drive our earnings growth. Moreover, last week's public announcement that we have begun to increase the supply of Cerezyme for patients with Gaucher disease to near-normal levels, and that supplies of Fabrazyme for patients with Fabry disease will increase beginning in the fourth quarter, further illustrates the progress we are making as well as the opportunistic nature of your proposal.

Notwithstanding this information and assistance, you have not increased your price above $69 per share. You and your advisors claim you are willing to pay more but that you are unwilling to "bid against yourself." The Genzyme board is not prepared to engage in merger negotiations with Sanofi based upon an opportunistic proposal with an unrealistic starting price that dramatically undervalues our company.

As you know, the Genzyme board includes representatives of some of our major shareholders. Our board has worked actively to understand the true value of our company and is unanimous and resolute in its commitment to maximize Genzyme's future value for all of our shareholders.

Yours truly,

Henri A. Termeer
Chairman and Chief Executive Officer

Genzyme noted that there is no need for company shareholders to take any action at this time. Genzyme's financial advisors are Credit Suisse Securities (USA) LLC and Goldman, Sachs & Co., and its legal advisor is Ropes & Gray LLP

In addition, at the August 29 meeting of the Company Board, the independent directors of the Company Board—which includes all directors except Mr. Termeer—determined to retain Wachtell, Lipton, Rosen & Katz ("Wachtell, Lipton") as legal counsel to the independent directors, and on August 30, 2010, Wachtell, Lipton was formally retained.

        In advance of a September 9, 2010 special meeting of the Company Board, Credit Suisse and Goldman Sachs were asked to summarize different options available to Sanofi, as well as strategic options potentially available to the Company. These summaries were presented to the Company Board during the September 9 meeting, during which Credit Suisse and Goldman Sachs also described Sanofi's ongoing actions, including its meetings with certain shareholders of the Company, as well as the reported reactions of those shareholders to Sanofi's proposal. After presentation of the summaries, the Company Board discussed the options available.

        On September 16, 2010, Mr. Termeer received a telephone call from Mr. Viehbacher. Mr. Viehbacher indicated that he had discussed Sanofi's interest in the Company with Carl Icahn, a major shareholder of the Company, and that Mr. Icahn had suggested Mr. Viehbacher reach out to Mr. Termeer. During the phone call, Mr. Viehbacher proposed a meeting with Mr. Termeer to discuss Sanofi's proposal. Mr. Termeer accepted Mr. Viehbacher's invitation.

        On September 17, 2010, Mr. Termeer informed Mr. Wirth and Mr. Wyzga of Mr. Viehbacher's call and then also discussed the call and proposed meeting with Mr. Whitworth and Mr. Carpenter, members of the Strategic Planning Committee. Mr. Wirth subsequently discussed Mr. Viehbacher's call with Mr. Bertolini, the remaining member of the Strategic Planning Committee, on September 18, 2010. The Strategic Planning Committee instructed Mr. Termeer that during the meeting, he should discuss the intrinsic value of the Company, but otherwise should listen and report back on Mr. Viehbacher's proposal.

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        The meeting between Mr. Termeer and Mr. Viehbacher took place on September 20, 2010, and included Mr. Wirth and Sanofi's Chief Financial Officer, Jérôme Contamine. During the meeting, Mr. Viehbacher focused his remarks on elaborating on his previously expressed position that the unaffected Share price of the Company prior to rumors of Sanofi's interest in acquiring the Company fairly reflected the Company's prospects and the risks inherent in its recovery from the manufacturing interruption at its Allston Landing biologics manufacturing facility, requested that Mr. Termeer provide a price range at which a deal could be consummated, and proposed that the parties agree to a price range of from $69.00 per Share to $80.00 per Share. Mr. Termeer, consistent with the Strategic Planning Committee's instructions and the Company Board's position with respect to Sanofi's proposal, declined to agree to Mr. Viehbacher's proposed price range of $69.00 per Share to $80.00 per share or to suggest any other price range, but he discussed at length the intrinsic value of the Company, reiterated the Company Board's unanimous view that $69.00 per Share was an inappropriate price at which to commence negotiations or diligence and encouraged Mr. Viehbacher to demonstrate his commitment to acquiring the Company by raising his offer to a price that would more fairly reflect the Company's intrinsic value and persuade the Company Board to enter into discussions with Sanofi. In the course of the discussion, Mr. Viehbacher also noted that as a result of his discussions with shareholders of the Company, he believed a transaction between Sanofi and the Company was of interest to the Company's shareholders but avoided any statement that the Company's shareholders had any interest in such a transaction at a price of $69.00 per Share. Mr. Viehbacher further indicated that Sanofi was potentially willing to raise its proposed per Share consideration from $69.00 per Share, but not until he was provided by the Company with a range at which the Company believed a deal could be consummated. Mr. Termeer, consistent with the Company Board's direction, again declined to discuss any particular price range, and instead focused his remarks on the intrinsic value of the Company, the progress the Company was making in recovering from its manufacturing interruption and resupplying the market for Cerezyme and Fabrazyme, the potential recovery in the Company's financial results expected during 2011 that was not yet fully reflected in market expectations and the substantial commercial potential of alemtuzumab in MS. Throughout the meeting, Mr. Viehbacher stated that his proposed price range of $69.00 per Share to $80.00 per Share was manageable, but that, based on his current understanding, he could not get to $80.00 per Share. At the end of the meeting, Mr. Viehbacher noted that he believed Sanofi had three options: (1) to walk away from a possible deal with the Company, which Mr. Viehbacher indicated was an unacceptable option in light of the value of the transaction to Sanofi and the substantial time he had put into the proposed deal; (2) to try to engage further with the Company and the Company Board, which seemed difficult in light of the Company's position; or (3) to launch a public tender offer. Mr. Viehbacher indicated at that time that he was of the view that Sanofi had no choice but to commence a tender offer.

        The next day, on September 21, 2010, Mr. Termeer reported the full details of the meeting to the Company Board. The Company's legal and financial advisors discussed the options available to Sanofi, including the consequences of Sanofi launching a tender offer without the support of the Company Board. After discussion of the meeting as well as the potential implications of a public tender offer by Sanofi, the Company Board reconfirmed that $69.00 per Share was not an appropriate price at which it would allow Sanofi to commence due diligence or at which negotiations should begin, and instructed management to prepare and implement an aggressive program to communicate with the Company's shareholders about the intrinsic value of the Company.

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        On October 4, 2010, Sanofi sent a letter to Mr. Termeer stating that Sanofi would commence a tender offer to acquire all outstanding Shares at $69.00 per Share. The text of that letter is set forth below:

October 4, 2010

VIA EMAIL, TELECOPIER AND DHL
Mr. Henri Termeer
Chairman, President and Chief Executive Officer
Genzyme Corporation
500 Kendall Street
Cambridge, Massachusetts 02142
USA

Dear Henri,

We are disappointed that you remain unwilling to have constructive discussions with us regarding our offer to acquire Genzyme Corporation. We continue to believe that our proposal is compelling for you shareholders and would provide them with immediate and substantial value that reflects the potential of Genzyme's business and pipeline.

Subsequent to making our offer public on August 29, 2010, we met with your largest shareholders owning collectively over 50% of Genzyme's outstanding shares. It was clear from our meetings that your shareholders are supportive of our initiative and, like us, are frustrated with your refusal to have meaningful discussions with us regarding our proposal. Your continued refusal to engage with us in a constructive manner is denying your shareholders an opportunity to receive a substantial premium, to realize immediate liquidity, and to protect against the risks associated with Genzyme's business and operations.

After several months of our repeated requests for a meeting with you, we finally met on September 20, 2010. Unfortunately, this meeting was not productive. In an effort to advance our discussions, I shared a very narrow information request focused on confirming your anticipated manufacturing recovery. Even though we and the market have analyzed and assessed the prospects for alemtuzumab, I proposed a meeting with your commercial team to understand their perspectives on the role alemtuzumab could play in the evolving multiple sclerosis market. You were unwilling to pursue either of these or any other path forward. You were also unwilling to provide us with your perspective on an appropriate valuation for Genzyme.

You have, therefore, left us no alternative but to commence a tender offer and take our offer directly to your shareholders. We strongly believe that our offer price of $69.00 per share in cash is compelling and represents substantial value for Genzyme's shareholders.

This offer represents a premium of 38% over Genzyme's unaffected share price of $49.86 on July 1, 2010, the day prior to the press speculation regarding Sanofi-Aventis' potential acquisition plans for a large US biotech company. It also represents a premium of almost 31% over the one-month historical average share price through July 22, 2010, the day prior to press speculation that Sanofi-Aventis had made an approach to acquire Genzyme.

We believe that a combination of our two businesses would be beneficial to our respective shareholders and employees, and the patients and physicians we serve. Sanofi-Aventis would put its full resources behind Genzyme to invest in developing new treatments, enhance penetration in existing markets and further expand into emerging markets. Sanofi-Aventis is well positioned to help Genzyme address its manufacturing problems. Genzyme would become the global center for excellence for Sanofi-Aventis in rare diseases and this unit would be managed as a stand-alone division under the Genzyme brand, with its own R&D, manufacturing and commercial infrastructure. Genzyme's management and employees

28

would play a key role within Sanofi-Aventis, and the combination would further increase Sanofi-Aventis' presence in the greater Boston area.

It remains our strong preference to work together with you to reach a mutually agreeable transaction. However, given your unwillingness to engage in constructive discussions with us, we had no choice but to commence a tender offer. Given our commitment to this transaction, we will continue to consider all alternatives for consummating an acquisition of Genzyme. We believe it is in the best interests of both companies, and our respective shareholders and other constituencies, to move forward quickly to complete this transaction. We and our advisors are available to meet with you to discuss the terms of our offer and to conclude a transaction expeditiously.

Yours sincerely,

Sanofi-Aventis

By: Christopher A. Viehbacher
      Chief Executive Officer

cc: Genzyme Board of Directors

        Also on October 4, 2010, after delivering its letter to Mr. Termeer, Sanofi formally commenced the Offer and filed the Schedule TO with the SEC. Promptly thereafter, the Company issued a press release urging its shareholders to take no action on the Offer until the Company Board made its recommendation.

        On October 5, 2010, the Strategic Planning Committee met to discuss the terms of the Offer. From October 5 - 7, 2010, the Company held meetings, at which the Company Board heard presentations from each of its business units, reviewed the status of its product pipeline, and reviewed the Company's financial forecast. During these meetings, the Company Board reviewed the terms of the Offer and considered a number of factors in connection with the Company Board's recommendation to the Company's shareholders regarding the Offer. The Company Board considered presentations by Credit Suisse and Goldman Sachs regarding the Offer, including the opinions of Credit Suisse and Goldman Sachs delivered orally to the directors (which were subsequently confirmed in writing on October 7, 2010) as to the inadequacy of the Offer price or the Offer (as set forth in the respective written opinions), from a financial point of view, to the Company's shareholders (other than in the case of the opinion of Goldman Sachs, the Offeror and any of its affiliates), as well as the advice of counsel. The Company Board and its advisors discussed the process for communicating the Company Board's recommendation to the Company's shareholders and preparations for a future meeting at which the Company would present information with regard to the Company's business and outlook to the Company's shareholders. On October 7, 2010, the Company Board reviewed and confirmed the reasons for its recommendation set forth below (see Item 4 "—Reasons for the Recommendation of the Company Board), unanimously determined that the Offer was inadequate and not in the best interests of the Company's shareholders, and unanimously recommended that the Company's shareholders reject the Offer and not tender their Shares pursuant to the Offer.

Reasons for the Recommendation of the Company Board

The Offer is based on financial terms identical to those in the two prior unsolicited proposals submitted by Sanofi, which the Company Board previously rejected. The Company Board remains unanimously resolute in its belief that the $69.00 per Share Offer Price continues to be inadequate and opportunistic, fails to recognize the Company's plan for substantial value creation, substantially undervalues the Company relative to its intrinsic value and is not in the best interests of Genzyme or its shareholders.

        The Company Board has reviewed and considered the Offer, after consultation with members of management and its financial and legal advisors. In addition, the independent directors have considered

29

legal advice from their counsel, Wachtell, Lipton. After considering its fiduciary duties under applicable law, the Company Board has unanimously determined that the Offer is inadequate and is not in the best interests of the Company or the Company's shareholders. Accordingly, the Company Board unanimously recommends that Genzyme shareholders reject the Offer and not tender their Shares pursuant to the Offer.

        The Company Board considered each of the following factors, among others, when reaching its recommendation that the Company's shareholders should reject the Offer and not tender their Shares pursuant to the Offer:

Sanofi's $69.00 per Share Offer Fails to Compensate the Company's Shareholders for the Value of the Company's Unique and Industry-Leading Franchise

•

Unique Biotechnology Franchise.  Genzyme pioneered the orphan drug market and is consistently recognized as the industry leader. The Company's portfolio includes 12 market leading therapies with durable revenue streams. The Company has developed long-standing relationships with its patients through its personalized approach to treating specialized patient populations.

•

Long History of Research and Development Success.  The Company's commitment to discovering and developing novel therapies that set new standards of care serves as the foundation for the Company's future success. The Company has recruited some of the world's most respected scientists and has commercialized a dozen market leading products that serve unmet patient needs. This commitment to novel therapies helped the Company deliver compound annual revenue growth of 23% from 2002 to 2009. The Company has an extensive number of Phase 2 and Phase 3 trials underway, highlighting its continuing commitment to finding new medicines to serve the best interests of patients, which in turn will help drive future shareholder value for our shareholders.

Sanofi's Opportunistic Offer Fails to Recognize the Substantial Value Creation Potential of the Company's Five-Point Plan—Which Rightfully Belongs to Genzyme's Shareholders. In May 2010, the Company established a five point plan to restore its manufacturing platform, capitalize on new product opportunities and optimize its capital structure. Genzyme has made significant progress on executing on this plan and the Company Board believes that given the opportunity to fully execute the plan, the Company has the potential to generate substantially more value for shareholders than the Offer Price.

•

The Offer Does Not Reflect the Value of the Company's Five Point Plan.  The Company Board recognized that significant value could be delivered to its shareholders through changes to its businesses and capital structure. After a significant period of study, including input from outside consultants, key new hires and the strengthening of the Company Board, the Company announced a substantial and comprehensive value-enhancing plan for the business in May 2010. These changes included:

•

Focusing on its core businesses and restoring its track record of manufacturing excellence;

•

Capitalizing on product opportunities that are expected to be near-term value drivers, including maximizing the potential of Myozyme, Synvisc-One, and Mozobil, exciting new products that are early in their launch stages, as well as alemtuzumab for MS, mipomersen and eliglustat, important therapies that are expected to be launched over the next three years;

•

Disposing of non-core businesses and taking advantage of the Company's core franchise strengths;

•

Reducing costs and improving operating margins; and

•

Optimizing the Company's capital structure.

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•

The Offer Does Not Reflect The Progress the Company has Already Made—and Expects to Continue to Make—in Furtherance of its Five Point Plan.  In the short period of time since the announcement of this plan, the Company already has made significant progress in its execution including:

•

Agreeing to sell its Genetic testing business for $925 million and proceeding towards the sale of its Diagnostic products and Pharmaceutical intermediates businesses. These actions are intended to optimize the Company's business mix and are expected to be accretive to earnings and improve cash return on invested capital;

•

Finalizing its consent decree with the U.S. Food and Drug Administration ("FDA");

•

Making substantial progress towards restoring its manufacturing platform:

•

The Company is on-track to transition all of its fill/finish operations out of the Company's Allston facility in November 2010 and, by the end of 2012, to increase by four-fold over 2004 levels the bioreactor capacity needed to manufacture the Company's core products; and

•

The Company has also been able to increase supply of Cerezyme and Fabrazyme, forecasting that Cerezyme patients will be able to return to normal dosing by September 2010 and Fabrazyme patients will be able to double their doses during the last three months of 2010;

•

Developing a multiple year plan, which was based on the advice of independent consultants and focused on potential efficiencies and cost reductions to improve the Company's operating margins. Implementation of this plan will commence in 2010, and will be overseen and directed by the Strategic Planning Committee;

•

Implementing the first half of a planned $2 billion stock repurchase program by entering into a $1 billion accelerated share repurchase plan in June 2010, which was financed by the Company's issuance of $1 billion in debt; and

•

Identifying opportunities to deploy the substantial cash flow expected to be generated by the Company in order to maximize shareholder value.

        The Offer Does Not Reflect Genzyme's Valuable Pipeline.    Sanofi has stated that a key reason for its Offer is to capture the Company's valuable product pipeline. In addition to failing to reflect the value of restoration of the Company's manufacturing platform, the Company Board believes the Offer also does not reflect the value of the three new products that are expected to be launched by the end of 2013.

•

Alemtuzumab for multiple sclerosis (MS)—a potentially transformative once yearly therapy, which would address the large and growing MS market that is projected to reach $14 billion by 2012. The Company believes that this therapy will establish a new standard of efficacy for MS treatment and deliver differentiated durability, convenience and tolerability with a manageable safety profile to this important market;

•

Mipomersen for severe hypercholesterolemia—a novel therapy for patients with uncontrolled LDL cholesterol on maximally tolerated lipid lowering therapy; and

•

Eliglustat and eliglustat for Type 1 Gaucher disease—a potentially transformative oral therapy candidate with the potential for a rapid impact on bone disease.

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The Offer Price Does Not Adequately Compensate Genzyme Shareholders for the Strategic Importance and Financial Benefit to Sanofi of the Transaction.

•

Strategic Importance—Gaps in Sanofi's Pipeline.  According to a July 29, 2010 Reuters report, more than a fifth of Sanofi's 2008 drug revenues face patent expirations through 2013, which does not even include the impact of generic sales of Lovenox. In July 2010, the FDA approved a generic version of Lovenox, one of Sanofi's top selling products. Sanofi is also expected to lose U.S. patent protection for Plavix, another of its top selling products, next year. Most recently, according to a Reuters report on September 28, 2010, two Sanofi patents that would have protected its oncology product Taxotere until 2013 were invalidated by the U.S. District Court for the District of Delaware, clearing the way for potential generic competition.

•

Strategic Importance—Genzyme Product Launches.  The Company expects to launch three products by the end of 2013, including alemtuzumab for MS, a potentially transformative therapy for the disease. The Company Board does not believe that the Offer Price reflects the importance of an acquisition of the Company to Sanofi, from both a timing and revenue generation standpoint.

•

The "Very Significant" Synergy Opportunity Available to Sanofi.  On an August 30, 2010 conference call with analysts, Sanofi stated that they "expect to achieve meaningful annual synergies" that are "very significant…probably in excess of numbers I've certainly seen in [research] notes to date", including both revenue and cost synergies. The Company Board does not believe that the Offer Price reflects these significant financial benefits.

The Offer is Financially Inadequate. The Company Board believes that the Offer is financially inadequate and does not reflect the intrinsic value of the Company after considering the following:

•

Opinion of Credit Suisse.   Credit Suisse rendered its opinion to the Company Board, subsequently confirmed in writing, that, as of October 7, 2010 and based upon and subject to the factors and assumptions set forth in the written opinion the Offer was inadequate, from a financial point of view, to such holders. The full text of the written opinion of Credit Suisse, dated October 7, 2010, which sets forth assumptions made, procedures followed, matters considered and limitations on the review undertaken in connection with the opinion, is attached as Annex A. Credit Suisse provided its opinion for the information of the Company Board in connection with its consideration of the Offer. The opinion of Credit Suisse does not constitute advice or a recommendation to any holder of Shares as to how such holder should act on any matter relating to the Offer.

•

Opinion of Goldman, Sachs & Co.  Goldman Sachs rendered its opinion to the Company Board, subsequently confirmed in writing, that, as of October 7, 2010 and based upon and subject to the factors and assumptions set forth in the written opinion, the consideration proposed to be paid to the holders of Shares (other than the Offeror and any of its affiliates) pursuant to the Offer was inadequate, from a financial point of view, to such holders. The full text of the written opinion of Goldman Sachs, dated October 7, 2010, which sets forth assumptions made, procedures followed, matters considered and limitations on the review undertaken in connection with the opinion, is attached as Annex B. Goldman Sachs provided its opinion for the information and assistance of the Company Board in connection with its consideration of the Offer. The opinion of Goldman Sachs is not a recommendation as to whether or not any holder of the Shares should tender such Shares in connection with the Offer or any other matter.

Accordingly, the Company Board unanimously recommends that shareholders reject the Offer and NOT tender their Shares pursuant to the Offer.

        The Company Board has recommended that management embark on a program to communicate with the Company's shareholders about the intrinsic value of the Company. Accordingly, the Company intends to host a webcast and presentation to shareholders at a meeting in the near future, providing an updated financial outlook and other pertinent information. Subsequent meetings with shareholders

32

are planned to be held in major U.S. cities in the following days. Details on the meetings will be announced separately.

        The foregoing discussion of information and factors considered by the Company Board is not intended to be exhaustive. In light of the variety of factors considered in connection with its evaluation of the Offer, the Company Board did not find it practicable to, and did not, quantify or otherwise assign relative weights to the specific factors considered in reaching its determinations and recommendations. Moreover, each member of the Company Board applied his or her own personal business judgment to the process and may have given different weight to different factors.

(c)   Intent to Tender.

        To the knowledge of the Company, after reasonable inquiry, none of the Company's executive officers, directors, affiliates and subsidiaries currently intends to tender into the Offer or sell any Shares held of record or beneficially owned by such person.

Item 5.    Person/Assets, Retained, Employed, Compensated or Used.

        The Company has retained Credit Suisse and Goldman Sachs to act as its financial advisors in connection with among other things, the Company's analysis and consideration of, and response to, the Offer. The Company has agreed to pay Credit Suisse and Goldman Sachs customary fees consisting of an initial upfront fee, a fixed quarterly financial advisory fee for up to four quarters and, in the event a sale of the Company is effected with Sanofi or any other person, a transaction fee based on the aggregate consideration paid in such transaction. The Company has also agreed to reimburse Credit Suisse and Goldman Sachs for their reasonable expenses, including attorneys' fees and disbursements, and to indemnify Credit Suisse and Goldman Sachs and related persons against certain liabilities in connection with their engagements.

        The written opinion of Credit Suisse attached as Annex A hereto lists other investment banking and other financial services Credit Suisse and its affiliates have in the past provided, and are currently providing, to the Company and its affiliates for which Credit Suisse and its affiliates have received, or would expect to receive, compensation. The written opinion of Goldman Sachs attached as Annex B hereto lists other investment banking services Goldman Sachs has provided, and is currently providing to the Company and its affiliates for which its Investment Banking Division has received, and may receive, compensation.

        The Company has retained Innisfree to provide consulting, analytic and information agent services in connection with the Offer, and to assist with communications with the Company's shareholders. The Company has agreed to pay Innisfree customary compensation for such services. In addition, the Company has agreed to reimburse Innisfree for its out-of-pocket expenses and to indemnify it against certain liabilities in connection with its engagement.

        The Company has retained Kekst and Company Inc. ("Kekst") as its public relations advisor in connection with the Offer. The Company has agreed to pay Kekst customary compensation for such services. In addition, the Company has agreed to reimburse Kekst for its out-of-pocket expenses and to indemnify it against certain liabilities in connection with its engagement.

        Except as set forth above, neither the Company nor any person acting on its behalf has or currently intends to employ, retain or compensate any person to make solicitations or recommendations to the shareholders of the Company on its behalf with respect to the Offer.

Item 6.    Interest in Securities of the Subject Company.

        As discussed in Item 4 "—Reasons for the Recommendation of the Company Board," on June 17, 2010, the Company issued the Notes. The Notes were offered and sold either to "qualified beneficial owners" pursuant to Rule 144A under the Securities Act of 1933, as amended (the "Securities Act"), or to persons outside the United States under Regulation S of the Securities Act. As discussed in Item 5

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"Persons/Assets, Retained, Employed, Compensated or Used," also on June 17, 2010, the Company entered into a master confirmation agreement and supplemental confirmation agreement with Goldman Sachs to effect an accelerated repurchase of $1 billion of the Company's Shares. Other than the issuance of the Notes, the accelerated share repurchase program and in the ordinary course of business in connection with the Company's employee benefit plans, no transactions in the Company's securities have been effected during the past 60 days by the Company, or, to the best of the Company's knowledge after reasonable inquiry and a review of Form 4 filings, by any of the Company's directors, executive officers, affiliates or subsidiaries, except that on August 20, 2010, Charles L. Cooney made a gift of 375 Shares.

Item 7.    Purpose of the Transaction and Plans or Proposals.

        For the reasons discussed in Item 4 "—Reasons for the Recommendation of the Company Board," the Company Board unanimously determined that the Offer is inadequate and not in the best interests of the Company. Accordingly, the Company Board unanimously recommends, on behalf of the Company, that the Company's shareholders reject the Offer and not tender their Shares pursuant to the Offer. The Company routinely maintains contact with other participants in its industry regarding a wide range of business transactions. It has not ceased, and has no intention of ceasing, such activity as a result of the Offer. The Company Board, in order to be fully informed about the Company's value in comparison with the Company's stand-alone strategic plan, has authorized the Company's advisors and management to probe and evaluate alternatives for the Company and its assets, which will include contacting third parties. These probes do not constitute authorization of a process to sell the Company or any of its assets. The Company's policy has been, and continues to be, not to disclose the existence or content of any such discussions or negotiations with third parties (except as may be required by law) as any such disclosure could jeopardize any future discussions or negotiations that the Company may conduct. The Company may determine to pursue discussions or negotiations with various parties, and, in the course of such discussions, the Company may enter into confidentiality agreements and may supply confidential information to one or more parties. Except as described in this Schedule 14D-9 (including in the Exhibits to this Schedule 14D-9) or as incorporated in this Schedule 14D-9 by reference, including, without limitation, the actions contemplated to be taken pursuant to the Company's five point plan to increase shareholder value described in Item 4 "—Reasons for the Recommendation of the Company Board," the Company is not now undertaking or engaged in any discussions or negotiations in response to the Offer that relates to or would result in (1) a tender offer for, or other acquisition of, Shares or any other securities of the Company by Sanofi, any of its subsidiaries, or any other person, (2) any extraordinary transaction, such as a merger, reorganization or liquidation, involving the Company or any of its subsidiaries, (3) any purchase, sale or transfer of a material amount of assets of the Company or any of its subsidiaries or (4) any material change in the present dividend rate or policy, indebtedness or capitalization of the Company. Except as described or referred to in this Schedule 14D-9 or the annexes and exhibits to this Schedule 14D-9 or the Offer, there are no transactions, board resolutions, agreements in principle or contracts entered into in response to the Offer which relate to or would result in one or more of the matters referred to in the preceding sentence.

        Notwithstanding the foregoing, the Company may in the future engage in discussions or negotiations in response to the Offer that could have one of the effects specified in the preceding paragraph, and it has determined that disclosure with respect to the parties to, and the possible terms of, any transactions or proposals of the type referred to in the preceding paragraph might jeopardize the discussions or negotiations that the Company may conduct. Accordingly, the Company Board has instructed management not to disclose the possible terms of any such transactions or proposals, or the parties thereto, unless and until an agreement in principle relating thereto has been reached or, upon the advice of counsel, as required by law.

        As initially announced by the Company in May 2010, the Company is pursuing strategic alternatives for its Genetic testing, Diagnostic products and Pharmaceutical intermediates businesses.

34

The Company has entered into an agreement to sell its Genetic testing business unit and is targeting transactions for its Diagnostics products and Pharmaceutical intermediates business units by year-end.

Item 8.    Additional Information.

(a)   Appraisal Rights.

        The Company shareholders will not have appraisal rights in connection with the Offer. The Company believes that shareholders also would not be entitled to appraisal rights in connection with the Proposed Merger. Under Section 13.02(a)(1) of the MBCA, shareholders of a Massachusetts corporation generally are entitled to appraisal rights in the event of a merger, but such rights are subject to certain exceptions. One exception applies to a merger in which shareholders receive only cash in exchange for their shares and no director, officer or controlling shareholder of the corporation has a direct or indirect material financial interest in the merger other than in (i) his, her or its capacity as a shareholder of the corporation, (ii) his, her or its capacity as a director, officer, employee or consultant of the corporation or the acquiring company pursuant to bona fide arrangements with the corporation or the acquiring company or (iii) any other capacity so long as the shareholder owns less than 5% of the voting securities of the corporation.

        The Company believes this exception would be applicable in the Proposed Merger and that shareholders would not be entitled to appraisal rights in connection with the Proposed Merger. However, Section 13.02(a)(1) of the MBCA has not been the subject of judicial interpretation. Accordingly, it is possible that a court could conclude that no exception is applicable in connection with the Proposed Merger and that shareholders are entitled to appraisal rights under Massachusetts law. Any shareholder who believes he, she or it is entitled to appraisal rights and who wishes to preserve such rights should carefully review Sections 13.01 through 13.31 of the MBCA, which sets forth the procedures necessary to perfect appraisal rights. Failure to strictly comply with such procedures would result in the loss of any appraisal rights to which a shareholder may be entitled.

(b)   Anti-Takeover Statutes.

        Chapter 110F of the Massachusetts General Laws prevents an "interested stockholder" (including a person who owns or has the right to acquire 5% or more of a corporation's outstanding voting stock) from engaging in a "business combination" (defined to include mergers and certain other actions) with a Massachusetts corporation for a period of three years following the date that such interested stockholder became an interested stockholder unless:

(i)

prior to the date such person became an interested stockholder, the board of directors of the corporation approved either the business combination or the transaction in which the interested stockholder became an interested stockholder;



(ii)

upon consummation of the transaction in which the interested stockholder became an interested stockholder, the interested stockholder owned at least 90% of the voting stock of the corporation outstanding at the time the transaction commenced (excluding, for purposes of determining the number of shares outstanding, stock held by directors who are also officers and by employee stock plans that do not allow plan participants to determine confidentially whether to tender shares); or



(iii)

on or subsequent to the date the business combination is approved by the board of directors of the corporation and authorized at a meeting of shareholders, and not by written consent, by the affirmative vote of the holders of at least 66²/3% of the outstanding voting stock of the corporation which is not owned by the interested stockholder.

        Chapter 110D of the Massachusetts General Laws restricts the voting rights of shares acquired in a control share acquisition, unless, among other things, the articles of organization or by-laws of a Massachusetts corporation provide that such restrictions are inapplicable. The Company's by-laws provide that the provisions of Chapter 110D do not apply to the Company, and, therefore such

35

restrictions will not be applicable to Shares purchased by Offeror in the Offer, unless the Company Board amends the Company's by-laws prior to the closing of the Offer. The Company Board reserves the right to amend the Company's by-laws, prior to the closing of the Offer, to elect to have the Company covered by Chapter 110D, in which event Shares purchased by Offeror in the Offer would be subject to Chapter 110D.

        Chapter 110C of the Massachusetts General Laws addresses take-over bids, which are acquisitions or offers to acquire more than 10% of the outstanding equity securities of a target company. Chapter 110C requires a bidder to publicly announce the terms of its offer and file certain disclosure with the Secretary of the Commonwealth of Massachusetts prior to making a take-over bid, and authorizes the Secretary of the Commonwealth of Massachusetts to hold a hearing regarding the take-over bid. Under Chapter 110C, a bidder that fails to disclose its intent to gain control over a target company prior to acquiring 5% of the target company's stock is precluded from making a takeover bid for one year after crossing the 5% threshold. Penalties for violating Chapter 110C include imprisonment for up to 3 years. Chapter 110C is similar, but not identical, to an Illinois statute that the Supreme Court determined was unconstitutional, and the United States Court of Appeals for the First Circuit has indicated that Chapter 110C is likely unconstitutional.

        Section 8.06(b) of the MBCA, provides that "notwithstanding anything to the contrary in [the MBCA] or in the articles or organization or bylaws of any public corporation, the terms of the directors of a public corporation shall be staggered by dividing the number of directors into 3 groups, as nearly equal number as possible ... ." As permitted under the MBCA, in 2006, the Company Board adopted a vote providing that the Company elected to be exempt from the provisions of Section 8.06(b). Under Section 8.06(b), the Company Board may, at any time, vote that election of directors again be subject to 8.06(b). The Company Board, accordingly, retains the ability to stagger election of directors at the 2011 annual meeting of shareholders or any subsequent annual meeting of shareholders.

        A shareholder rights plan is a device that gives shareholders, other than an entity that acquires above a certain threshold of a corporation's stock, the right to acquire equity at a discounted price. Section 6.24 of the MBCA authorizes the board of directors of a Massachusetts corporation to adopt shareholder rights plans with terms a board of directors determines are reasonable and in the best interests of the corporation. The Company does not have a shareholder rights plan in place, but the Company Board retains the ability to adopt such a rights plan in the future.

        Section 8.30(a)(3) of the MBCA, states: "In determining what the director reasonably believes to be in the best interests of the corporation, a director may consider the interests of the corporation's employees, suppliers, creditors and customers, the economy of the state, the region and the nation, community and societal considerations, and the long-term and short-term interests of the corporation and its shareholders, including the possibility that these interests may be best served by the continued independence of the corporation."

(c)   Regulatory Approvals.

Antitrust in the United States

        Under the HSR Act, and the rules that have been promulgated thereunder by the Federal Trade Commission (the "FTC"), certain acquisition transactions may not be consummated unless required information has been furnished to the Antitrust Division of the Department of Justice (the "Antitrust Division") and the FTC and certain waiting period requirements have been satisfied. The purchase of Shares by Offeror pursuant to the Offer is subject to such requirements. Sanofi is required to file a Notification and Report Form with the Antitrust Division and the FTC relating to its proposed acquisition of the Company. The Company received notice that Sanofi intended to file its Notification and Report Form in connection with the purchase of Shares pursuant to the Offer with the Antitrust Division and the FTC on October 4, 2010. If the filing was made on October 4, 2010, the Company will

36

be required to submit a responsive Notification and Report Form with respect to the Offer with the FTC and the Antitrust Division on or before 5:00 p.m., New York City time, on October 14, 2010.

        Under the provisions of the HSR Act applicable to the Offer, the acquisition of Shares pursuant to the Offer may be consummated following the expiration of a 15-day waiting period following the filing by Sanofi of its Notification and Report Form with respect to the Offer, unless Sanofi voluntarily pulls its initial Notification and Report Form as a prelude to re-filing, unless Sanofi receives a request for additional information or documentary material from the Antitrust Division or the FTC or unless the antitrust agencies grant early termination of the waiting period. If, within the initial 15-day waiting period, either the Antitrust Division or the FTC issues a request for additional information or documentary material concerning the Offer, the waiting period will expire 10 days after the date Sanofi certifies substantial compliance with the request, unless otherwise extended by court order.

        The Antitrust Division and the FTC frequently scrutinize the legality under the antitrust laws of transactions such as Offeror's or Sanofi's acquisition of Shares pursuant to the Offer. At any time before or after Offeror's acquisition of Shares pursuant to the Offer, the Antitrust Division or the FTC could take such action under the antitrust laws as either deems necessary or desirable in the public interest, including seeking to enjoin the purchase of Shares pursuant to the Offer, or seeking the divestiture of Shares acquired by Offeror or Sanofi or the divestiture of substantial assets of Sanofi or its subsidiaries or the Company or its subsidiaries. Private parties and individual state attorneys general may also bring legal actions under the antitrust laws. There can be no assurance that a challenge to the Offer on antitrust grounds will not be made, or, if such a challenge is made, the result thereof.

        If any waiting period under the HSR Act applicable to the Offer has not expired or been terminated prior to the expiration date of the Offer, or if the FTC, the Antitrust Division, a state attorney general, or a private party obtains an order enjoining the purchase of Shares, then Sanofi and Offeror will not be obligated to proceed with the Offer or the purchase of any Shares not previously purchased pursuant to the Offer. Additionally, Sanofi and Offeror may terminate the Offer if any action, proceeding, injunction, order or decree becomes applicable to Sanofi that seeks to restrain or prohibit the exercise by Sanofi of its full rights of ownership or operation of all or a portion of Sanofi's business or assets or those of the Company.

Foreign Competition Law Filings

        The Company conducts business in a number of foreign countries. In connection with the purchase of the Shares pursuant to the Offer, the laws of certain of these foreign countries may require the filing of information with, or the obtaining of the approval of, governmental authorities therein. As noted above, the Offer is conditioned upon receipt of approvals or notifications under applicable foreign antitrust, competition or merger control laws applicable to the purchase of Shares in the Offer. According to the Schedule TO, Offeror has indicated that intends to make a filing with the European Commission ("EU") pursuant to Article 7(1) of Council Regulation No. 139/2004, and that it does not intend to complete the offer until a decision has been made by the EU. Additionally, Offeror has noted in its Schedule TO that it intends to provide notice of the Offer to antitrust authorities in Brazil, Japan and Korea.

        Competition authorities in those or other countries may refuse to grant required approvals or clearances, bring legal action under applicable foreign antitrust laws seeking to enjoin the purchase of Shares pursuant to the Offer, or seek the divestiture of Shares acquired by Sanofi and Offeror or the divestiture of substantial assets of the Company or its subsidiaries or Sanofi or its subsidiaries. There can be no assurance that Sanofi and Offeror will obtain all required foreign antitrust approvals or clearances or that a challenge to the Offer by foreign competition authorities will not be made, or, if such a challenge is made, the result thereof.

37

Committee on Foreign Investment in the United States

        Under Section 721 of Title VII of the United States Defense Production Act of 1950, as amended, and the rules and regulations thereunder (the "Exon-Florio Amendment"), the President of the United States is authorized to prohibit or suspend acquisitions, mergers or takeovers by foreign persons of persons engaged in interstate commerce in the United States if the President determines, after investigation, that there is credible evidence that such foreign persons in exercising control of such acquired persons might take action that threatens to impair the national security of the United States and that other provisions of existing law do not provide adequate authority to protect national security. Pursuant to the Exon-Florio Amendment, a party or parties to a transaction may provide a notification to the Committee on Foreign Investment in the United States ("CFIUS"), which has been designated by the President to administer the Exon-Florio Amendment, for review of the transaction. Notification is not mandatory, but CFIUS has authority to initiate a review of a transaction in the absence of a voluntary notification, including after the transaction has closed.

        Once a review has been initiated (whether by notification or CFIUS's own initiative), CFIUS has 30 calendar days to decide whether to initiate a formal investigation. If CFIUS declines to investigate, the review process is complete. If CFIUS decides to investigate, it has 45 days in which to resolve the matter or prepare a recommendation to the President of the United States, who must then decide within 15 days whether to block the transaction. CFIUS may condition its clearance of a transaction upon commitments to be provided by the acquirer. These timetables may be extended in some circumstances if information is not provided as requested. Regardless of whether or not notification is made, there is no prohibition against the consummation of an acquisition, merger or takeover while a review is pending, but CFIUS retains jurisdiction to review a covered transaction following its consummation (unless a review was completed prior to closing).

        The Company is engaged in interstate commerce in the United States and Sanofi is a foreign person, and therefore the Offer is potentially subject to review under the Exon-Florio Amendment. To date, the Company has no knowledge of Sanofi's or the Offeror's intentions with respect to filing a notice of the Offer or the Proposed Merger with CFIUS.

(d)   Litigation

Federal Cases

        On August 11, 2010, Jerry L. & Mena M. Morelos Revocable Trust filed a lawsuit allegedly on behalf of a putative class of shareholders in the U.S. District Court for the District of Massachusetts against the Company, the Company Board and Sanofi (the "Morelos Action"). The suit alleges that the Company's directors breached their fiduciary duties by attempting to sell Genzyme without regard to the effect of a potential transaction on shareholders, adopting processes and procedures that will not benefit shareholders and engaging in self-dealing in order to obtain personal benefits not shared equally by all shareholders in connection with a purported proposed merger. The suit alleges that certain of the Company's directors are beholden to activist shareholders. The suit also alleges that the Company and Sanofi aided and abetted the purported breaches of fiduciary duties. The suit seeks, among other relief, (i) class action status, (ii) an order enjoining the defendants from consummating a transaction, unless and until Genzyme adopts procedures designed to obtain the best value for the its shareholders, (iii) an order directing the defendants to exercise their fiduciary duties and commence a sales process that is in the best interest of shareholders, (iv) an order rescinding, to the extent already implemented, any transaction agreement, (v) an order imposing a constructive trust in favor of the plaintiff and the putative class upon any benefits improperly received by the defendants as a result of any transaction, and (vi) an award to plaintiffs of the costs of the action, including reasonable attorneys' and experts' fees and expenses.

        A copy of the petition in the Morelos Action is attached hereto as Exhibit (a)(5). The foregoing description of the Morelos Action is qualified in its entirety by reference to Exhibit (a)(5) hereto.

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        On September 8, 2010, Bernard Malina filed a lawsuit allegedly on behalf of a putative class of shareholders in the U.S. District Court for the District of Massachusetts against the Company and the Company Board (the "Malina Action"). The suit alleges that the Company's directors breached their fiduciary duties by attempting to sell Genzyme without regard to the effect of a potential transaction on shareholders and engaging in a plan and scheme to obtain personal benefits at the expense of shareholders in connection with a purported proposed merger. The suit seeks, among other relief, (i) class action status, (ii) an order directing the defendants to exercise their fiduciary duties and commence a sales process that is in the best interest of shareholders, (iii) compensatory damages, and (iv) an award to plaintiffs of the costs of the action, including reasonable attorneys', accountants' and experts' fees and expenses.

        A copy of the petition in the Malina Action is attached hereto as Exhibit (a)(6). The foregoing description of the Malina Action is qualified in its entirety by reference to Exhibit (a)(6) hereto.

        On September 9, 2010, Emanuel Resendes filed a lawsuit allegedly on behalf of a putative class of shareholders in the U.S. District Court for the District of Massachusetts against the Company Board (the "Resendes Action"). The suit alleges that the Company's directors breached their fiduciary duties by attempting to sell Genzyme without regard to the effect of a potential transaction on shareholders and engaging in self-dealing in order to obtain personal benefits not shared equally by all shareholders in connection with a purported proposed merger. The suit seeks, among other relief, (i) class action status, (ii) an order enjoining the defendants from entering into any contract which harms the class or could prohibit the defendants from maximizing shareholder value, (iii) an order enjoining the defendants from initiating any defensive measures that would make the consummation of a transaction more difficult or costly for a potential acquiror, (iv) an order directing the defendants to exercise their fiduciary duties and refrain from advancing their own interests at the expense of the class and their fiduciary duties, and (v) an award to plaintiffs of the costs of the action, including reasonable attorneys' and experts' fees and expenses.

        A copy of the petition in the Resendes Action is attached hereto as Exhibit (a)(7). The foregoing description of the Resendes Action is qualified in its entirety by reference to Exhibit (a)(7) hereto.

        On September 14, 2010, William S. Field, Trustee u/a dated October 12, 1991, by William S. Field Jr., filed a lawsuit allegedly on behalf of a putative class of shareholders in the U.S. District Court for the District of Massachusetts against the Company and the Company Board (the "Field Action"). The suit alleges that the Company's directors breached their fiduciary duties by failing to pursue the a transaction that would provide the highest value reasonably available for shareholders and by not providing full and fair disclosure to shareholders. The suit seeks, among other relief, (i) class action status, (ii) an order appointing an independent special committee to the Company with authority to evaluate, negotiate and, if in the best interests of shareholders, accept the Offer or a other offers, (iii) an award to plaintiffs of the costs of the action, including reasonable attorneys', accountants' and experts' fees and expenses and (iv) such other relief as the court deems proper.

        A copy of the petition in the Field Action is attached hereto as Exhibit (a)(8). The foregoing description of the Field Action is qualified in its entirety by reference to Exhibit (a)(8) hereto.

        The plaintiffs and the defendants in the Morelos Action, Malina Action, Resendes Action and Field Action expect to file a joint stipulation with the federal court seeking consolidation of the cases. The Company and its directors believe that the claims made by the stockholder plaintiffs in these federal actions are without merit and intend to defend them vigorously.

State Cases

        On August 16, 2010, plaintiff Chester County Employees' Retirement Fund filed a lawsuit allegedly on behalf of a putative class of shareholders in Massachusetts Superior Court (Middlesex County) against the Company and the Company directors (the "Chester Action"). An amended complaint was filed in the Chester Action on September 2, 2010. The amended complaint alleges that the defendants

39

breached their fiduciary duties by failing to adequately inform themselves regarding the potential offer by Sanofi or any offer by any other party and failing to pursue the best available transaction for shareholders. The suit seeks, among other relief, (i) class action status, (ii) an order enjoining the defendants from initiating any defensive measures designed to prevent shareholders from receiving and accepting a value-maximizing offer, (iii) an order directing the defendants to exercise their fiduciary duties to obtain a transaction in shareholders' best interests, (iv) compensatory damages and (v) an award to plaintiffs of the costs of the action, including reasonable attorneys' and experts' fees and expenses. On September 23, 2010, by joint motion of the parties, the Chester Action was transferred to the Business Litigation Session of Suffolk County Superior Court in Boston, Massachusetts.

        A copy of the amended complaint in the Chester Action is attached hereto as Exhibit (a)(9). The foregoing description of the Chester Action is qualified in its entirety by reference to Exhibit (a)(9) hereto.

        On August 17, 2010, Alan R. Kahn filed a lawsuit allegedly on behalf of a putative class of shareholders in the Massachusetts Superior Court (Middlesex County) against the Company, the Company's executive officers and the Company's directors (the "Kahn Action"). The suit alleges that the defendants breached their fiduciary duties in approving a proposed transaction and failing to negotiate in good faith with Sanofi. The suit seeks, among other relief, (i) class action status, (ii) an order enjoining the defendants from initiating any defensive measures that would inhibit the defendants' ability to maximize shareholder value, (ii) compensatory damages and (iii) an award to plaintiffs of the costs of the action, including reasonable attorneys' and experts' fees and expenses.

        A copy of the complaint in the Kahn Action is attached hereto as Exhibit (a)(10). The foregoing description of the Kahn Action is qualified in its entirety by reference to Exhibit (a)(10) hereto.

        On September 1, 2010, David Shade filed a lawsuit allegedly on behalf of a putative class of shareholders in the Massachusetts Superior Court (Middlesex County) against the Company, the Company's executive officers and the Company's directors (the "Shade Action"). The suit alleges that the defendants breached their fiduciary duties in rejecting all offers and approaches by Sanofi and refusing to engage in any negotiations with Sanofi. The suit seeks, among other relief, (i) class action status, (ii) a declaration that the defendants breached their fiduciary duties, (ii) compensatory damages and (iii) an award to plaintiffs of the costs of the action, including reasonable attorneys' fees and expenses and experts' fees.

        A copy of the complaint in the Shade Action is attached hereto as Exhibit (a)(11). The foregoing description of the Shade Action is qualified in its entirety by reference to Exhibit (a)(11) hereto.

        On September 2, 2010, the Louisiana Municipal Police Employees' Retirement System filed a lawsuit allegedly on behalf of a putative class of shareholders in the Massachusetts Superior Court (Middlesex County) against the Company, the Company's executive officers and the Company's directors (the "Louisiana Action"). The suit alleges that the defendants breached their fiduciary duties in rejecting all offers and approaches by Sanofi and refusing to engage in any negotiations with Sanofi. The suit seeks, among other relief, (i) class action status, (ii) a declaration that the defendants breached their fiduciary duties, (ii) compensatory damages and (iii) an award to plaintiffs of the costs of the action, including reasonable attorneys' fees and expenses and experts' fees.

        A copy of the complaint in the Louisiana Action is attached hereto as Exhibit (a)(12). The foregoing description of the Louisiana Action is qualified in its entirety by reference to Exhibit (a)(12) hereto.

        On October 5, 2010, plaintiffs and the defendants in the Chester Action, Kahn Action, Shade Action and Louisiana Action filed a joint stipulation with the Business Litigation Session of Suffolk County Superior Court in the Chester Action seeking consolidation of the state cases. On the same day, the Court signed an order approving the consolidation of these cases.

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        The Company and its directors believe that the claims made by the stockholder plaintiffs in these state actions are without merit and intend to defend them vigorously.

(f)    Cautionary Note Regarding Forward-Looking Statements.

        This Schedule 14D-9 contains forward-looking statements that are not historical facts. The Company has identified some of these forward-looking statements with words like "believe," "may," "could," "would," "might," "possible," "potential," "will," "should," "expect," "intend," "plan," "anticipate," "estimate," "approximate" "outlook," "forecast" or "continue" or the negative of these words, other terms of similar meaning or the use of future dates. Forward-looking statements in this Schedule 14D-9 include without limitation statements regarding the anticipated timing of filings and approvals relating to the transaction; statements regarding the expected timing of the completion of the transaction; statements regarding the ability to complete the transaction considering the various closing conditions; statements regarding alternatives for the Company and its assets; statements regarding the strategic plans of the Company, execution of the Company's five point plan, the potential of the Company's pipeline projects, and projected financial information; statements of expectation or belief; and statements of assumptions underlying any of the foregoing. Investors and security holders are cautioned not to place undue reliance on these forward-looking statements. Actual results could differ materially from those currently anticipated due to a number of risks and uncertainties. Risks and uncertainties that could cause results to differ from expectations include: uncertainties as to the timing of the Offer and Proposed Merger; uncertainties as to how many Company shareholders will tender their Shares in the Offer; the possibility that competing offers will be made; the possibility that various closing conditions will not be satisfied or waived, including that a governmental entity may prohibit, delay or refuse to grant approval for the consummation of the Offer or the Proposed Merger; the effects of disruption making it more difficult to maintain relationships with employees, customers, vendors and other business partners; the risk that shareholder litigation in connection with the Offer may result in significant costs of defense, indemnification and liability; other business effects, including the effects of industry, economic or political conditions outside of the Company's control; transaction costs; actual or contingent liabilities; risks associated with development, manufacturing and commercialization of products and product candidates; financial market conditions; and other risks and uncertainties discussed in the Company's filings with the SEC, including the information referred to under the heading "Risk Factors" section of the Company's quarterly report on Form 10-Q for the quarter ended June 30, 2010 and filed with the SEC on August 9, 2010. Copies of the Company's filings with the SEC may be obtained at the "Investors" section of the Company's website at http://www.genzyme.com. The Company does not undertake any obligation to update any forward-looking statements as a result of new information, future developments or otherwise, except as expressly required by law. All forward-looking statements in this Schedule 14D-9 are qualified in their entirety by this cautionary statement. The Company acknowledges that forward-looking statements made in connection with the Offer are not subject to the safe harbors created by the Private Securities Litigation Reform Act of 1995, as amended. The Company is not waiving any other defenses that may be available under applicable law.

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Item 9.    Exhibits.

        The following Exhibits are filed with this Schedule 14D-9:

Exhibit No.		Description
	(a)(1)	Press Release issued by Genzyme, dated October 7, 2010.
	(a)(2)	Letter to Genzyme shareholders, dated October 7, 2010.
	(a)(3)	Opinion of Credit Suisse, dated October 7, 2010 (included as Annex A to this Schedule 14D-9).
	(a)(4)	Opinion of Goldman Sachs, dated October 7, 2010 (included as Annex B to this Schedule 14D-9).
	(a)(5)	Petition filed by Jerry L & Mena M. Morelos Revocable Trust in the United State District Court for the District of Massachusetts on August 11, 2010.
	(a)(6)	Petition filed by Bernard Malina in the United States District Court for the District of Massachusetts on September 8, 2010.
	(a)(7)	Petition filed by Emanuel Resendes in the United States District Court for the District of Massachusetts on September 9, 2010.
	(a)(8)	Petition filed by William S. Field, III, Trustee u/a dated October 12, 1991 by William S. Field Jr., in the United States District Court for the District of Massachusetts on September 14, 2010.
	(a)(9)	Amended Complaint filed by the Chester County Employees Retirement Fund in the Massachusetts Superior Court for Middlesex County on August 16, 2010.
	(a)(10)	Complaint filed by Alan R. Kahn in the Massachusetts Superior Court for Middlesex County on August 17, 2010.
	(a)(11)	Complaint filed by David Shade in Massachusetts Superior Court for Middlesex County on September 1, 2010.
	(a)(12)	Complaint filed by Louisiana Municipal Police Employees' Retirement System in the Massachusetts Superior Court for Middlesex County on September 2, 2010.
	(e)(1)	Excerpts from the Company's Definitive Proxy Statement on Schedule 14A related to the 2010 Annual Meeting of Shareholders as filed with the Securities and Exchange Commission on April 26, 2010.
	(e)(2)	Amended and Restated agreement dated April 14, 2010 between Genzyme, Relational Investors LLC, Ralph V. Whitworth and the other parties identified therein (filed as Exhibit 99.1 to Genzyme's Form 8-K filed on April 15, 2010, and incorporated herein by reference).
	(e)(3)	Agreement dated June 9, 2010 by and among Genzyme Corporation, Icahn Partners LP, Icahn Partners Master Fund LP, Icahn Partners Master Fund II L.P., Icahn Partners Master Fund III L.P. and High River Limited Partnership (filed as Exhibit 99.1 to Genzyme's Form 8-K filed on June 9, 2010, and incorporated herein by reference).
	(e)(4)	Amended and Restated Executive Employment Agreement, effective as of December 31, 2008, between Genzyme and Henri A. Termeer (filed as Exhibit 10.2 to Genzyme's Form 8-K filed December 5, 2008, and incorporated herein by reference).

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Exhibit No.		Description
	(e)(5)	Amended and Restated Executive Employment Agreement effective as of December 31, 2008 between Genzyme and Peter Wirth (filed as Exhibit 10.3 to Genzyme's Form 8-K filed December 5, 2008, and incorporated herein by reference).
	(e)(6)	Form of Severance Agreement between Genzyme and its executive officers (filed as Exhibit 10.2 to Genzyme's Form 10-Q for the quarter ended September 30, 2007, and incorporated herein by reference).
	(e)(7)	Form of Indemnification Agreement between Genzyme and its executive officers (filed as Exhibit 10.1 to Genzyme's Form 10-Q for the quarter ended September 30, 2004, and incorporated herein by reference).
	(e)(8)	2001 Equity Incentive Plan, as amended (filed as Exhibit 10.14 to Genzyme's 10-K for 2006, and incorporated herein by reference).
	(e)(9)	Forms of Non-Statutory Stock Option Agreement for grants to executive officers under Genzyme's 2001 Equity Incentive Plan (filed as Exhibit 10.5 to Genzyme's Form 10-Q for the quarter ended June 30, 2008, and incorporated herein by reference).
	(e)(10)	Forms of Incentive Stock Option Agreement for grants to executive officers under Genzyme's 2001 Equity Incentive Plan (filed as Exhibit 10.6 to Genzyme's Form 10-Q for the quarter ended June 30, 2008, and incorporated herein by reference).
	(e)(11)	2004 Equity Incentive Plan, as amended (filed as Appendix B to Genzyme's Proxy Statement on Schedule 14A filed April 13, 2009 for the 2009 Annual Meeting of Shareholders, and incorporated herein by reference).
	(e)(12)	Forms of Incentive Stock Option Agreement for grants to executive officers under Genzyme's 2004 Equity Incentive Plan (filed as Exhibit 10.14.1 to Genzyme's Form 10-K for 2008, and incorporated herein by reference).
	(e)(13)	Forms of Nonstatutory Stock Option Agreement for grants to executive officers under Genzyme's 2004 Equity Incentive Plan (filed as Exhibit 10.14.2 to Genzyme's Form 10-K for 2008, and incorporated herein by reference).
	(e)(14)	Forms of Restricted Stock Unit Award Agreement for grants to executive officers under Genzyme's 2004 Equity Incentive Plan (filed as Exhibit 10.3 to Genzyme's Form 10-Q for the quarter ended March 31, 2008, and incorporated herein by reference).
	(e)(15)	Genzyme Senior Executive Annual Cash Incentive Program (filed as Exhibit 10.1 to Genzyme's Form 8-K filed December 5, 2008, and incorporated herein by reference).

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SIGNATURE

        After due inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Dated: October 7, 2010	GENZYME CORPORATION
	By:	/s/ PETER WIRTH
		Name:	Peter Wirth
		Title:	Executive Vice President

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Annex A

PRIVILEGED AND CONFIDENTIAL

October 7, 2010
Board of Directors
Genzyme Corporation
500 Kendall Street
Cambridge, MA 02142

Members of the Board:

        You have asked us to advise you with respect to the adequacy, from a financial point of view, of the Offer (as defined below) made by Sanofi-Aventis (the "Acquiror") to the holders of common stock, par value $0.01 per share ("Company Common Stock"), of Genzyme Corporation (the "Company"). Upon the terms and subject to the conditions set forth in the Offer to Purchase, dated October 4, 2010 and in the related letter of transmittal (together, the "Offer to Purchase") GC Merger Corp., an indirect wholly owned subsidiary of the Acquiror (the "Acquisition Sub") has commenced an offer to purchase all of the outstanding shares of Company Common Stock at a purchase price of $69.00 per share (the "Offer Price"), net to the seller in cash, without interest (the "Offer"). As more fully described in the Offer to Purchase, the Acquiror has stated that it intends, promptly following consummation of the Offer, to seek to have the Company consummate a merger or other similar business combination with Acquisition Sub or another subsidiary of the Acquiror pursuant to which all remaining public shareholders of the Company would receive the highest price paid per share pursuant to the Offer, without interest.

        In arriving at our opinion, we have reviewed the Offer to Purchase and a draft dated October 7, 2010 of the Company's Solicitation/Recommendation Statement on Schedule 14D-9, to be filed with the Securities and Exchange Commission and certain related agreements and certain other information relating to the Company, including Company management's financial forecasts for the Company (the "Forecasts") and certain adjustments thereto reviewed and discussed by the Board of Directors of the Company, provided to or discussed with us by the Company and have met with the Company's management to discuss the business and prospects of the Company. We have also considered certain financial and stock market data of the Company, and we have compared that data with similar data for other publicly held companies in businesses we deemed similar to that of the Company and we have considered, to the extent publicly available, the financial terms of certain other business combinations and other transactions which have recently been effected. We also considered such other information, financial studies, analyses and investigations and financial, economic and market criteria which we deemed relevant.

        In connection with our review, we have not independently verified any of the foregoing information and have assumed and relied on such information being complete and accurate in all material respects. With respect to the Forecasts, the management of the Company has advised us, and we have assumed, that the Forecasts have been reasonably prepared on bases reflecting the best currently available estimates and judgments of the Company's management as to the future financial performance of the Company. We have not been requested to make, and have not made, an independent evaluation or appraisal of the assets or liabilities (contingent or otherwise) of the Company, nor have we been furnished with any such evaluations or appraisals.

        Our opinion addresses only the adequacy, from a financial point of view, to the holders of Company Common Stock of the Offer and does not address any other aspect or implication of the Offer or any other agreement, arrangement or understanding to be entered into in connection with the Offer or otherwise, including, without limitation, the fairness of the amount or nature of, or any other aspect relating to, any compensation to any officers, directors or employees of the Company, or class of

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such persons, relative to the Offer Price or otherwise. The issuance of this opinion was approved by our authorized internal committee.

        Our opinion is necessarily based upon information made available to us as of the date hereof and financial, economic, market and other conditions as they exist and can be evaluated on the date hereof.

        We are acting as financial advisor to the Board of Directors in connection with the Offer. We have received a fee and expect to receive additional fees for our services. In addition, the Company has agreed to indemnify us and certain related parties for certain liabilities and other items arising out of or related to our engagement. We and our affiliates have in the past provided and, are currently providing and in the future we may provide, investment banking and other financial services to the Company and its affiliates, for which we and our affiliates have received, and would expect to receive, compensation, including having acted as financial advisor to the Company in connection with a proxy contest in connection with the Company's 2010 annual meeting of shareholders in June 2010, as underwriter in connection with the offering of the Company's 3.625% Senior Notes due 2015 and 5.000% Senior Notes due 2020 in June 2010, in assisting the Company in structuring its $1 billion accelerated stock repurchase program in June 2010, and as financial advisor to the Company in connection with the sale of its interest in its Genetic Testing business unit in September 2010. We and our affiliates may have provided other financial advice and services, and may in the future provide financial advice and services, to the Company, the Acquiror and their respective affiliates for which we and our affiliates have received, and would expect to receive, compensation. We are a full service securities firm engaged in securities trading and brokerage activities as well as providing investment banking and other financial services. In the ordinary course of business, we and our affiliates may acquire, hold or sell, for our and our affiliates own accounts and the accounts of customers, equity, debt and other securities and financial instruments (including bank loans and other obligations) of the Company, the Acquiror and any other company that may be involved in the Offer, as well as provide investment banking and other financial services to such companies.

        It is understood that this letter is for the information of the Board of Directors of the Company in connection with its consideration of the Offer and does not constitute advice or a recommendation to any shareholder as to how such shareholder should act on any matter relating to the proposed Offer.

        Based upon and subject to the foregoing, it is our opinion that, as of the date hereof, the Offer is inadequate, from a financial point of view, to holders of Company Common Stock.

Very truly yours,

CREDIT SUISSE SECURITIES (USA) LLC

By:  /s/ CREDIT SUISSE SECURITIES (USA) LLC

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Annex B  

Goldman, Sachs & Co. -- 200 West Street -- New York, New York 10282
Tel. 212-902-1000 -- Fax. 212-902-3000

PERSONAL AND CONFIDENTIAL

October 7, 2010
Board of Directors
Genzyme Corporation 500 Kendall Street
Cambridge, MA 02142

Ladies and Gentlemen:

        You have requested our opinion as to the adequacy from a financial point of view to the holders (other than the Offeror (as defined below) and any of its affiliates) of the outstanding shares of common stock, par value $0.01 per share (the "Shares"), of Genzyme Corporation (the "Company") of the $69.00 per Share in cash (the "Consideration") proposed to be paid to such holders in the Offer (as defined below). The terms of the offer to purchase (the "Offer to Purchase") and related letter of transmittal (which, together with the Offer to Purchase, constitutes the "Offer") contained in the Tender Offer Statement on Schedule TO filed by sanofi-aventis ("Parent") and GC Merger Corp., an indirect wholly owned subsidiary of Parent (the "Offeror"), with the Securities and Exchange Commission on October 4, 2010, as amended through Amendment No. 2 to the Tender Offer Statement on Schedule TO filed by Parent and the Offeror with the Securities and Exchange Commission on October 6, 2010 (as amended, the "Schedule TO"), provide for an offer for all of the Shares pursuant to which, subject to the satisfaction of certain conditions set forth in the Offer, the Offeror will pay the Consideration for each Share accepted. We note that the Offer to Purchase provides that, following consummation of the Offer, the Offeror intends to seek to have the Company consummate a merger or other similar business combination with the Offeror or another subsidiary of Parent (the "Merger" and, together with the Offer, the "Transactions") in which all remaining public shareholders of the Company would receive the highest price paid per Share pursuant to the Offer, without interest.

        Goldman, Sachs & Co. and its affiliates are engaged in investment banking and financial advisory services, commercial banking, securities trading, investment management, principal investment, financial planning, benefits counseling, risk management, hedging, financing, brokerage activities and other financial and non-financial activities and services for various persons and entities. In the ordinary course of these activities and services, Goldman, Sachs & Co. and its affiliates may at any time make or hold long or short positions and investments, as well as actively trade or effect transactions, in the equity, debt and other securities (or related derivative securities) and financial instruments (including bank loans and other obligations) of the Company, Parent and any of their respective affiliates and third parties or any currency or commodity that may be involved in the Transactions for their own account and for the accounts of their customers. We are acting as financial advisor to the Company in connection with its consideration of the Offer and other matters pursuant to our engagement by the Company. We expect to receive fees for our services in connection with our engagement, including advisory fees that will be payable whether or not the Offer is consummated. The Company has agreed

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to reimburse our expenses arising, and indemnify us against certain liabilities that may arise, out of our engagement. We have provided, and are currently providing, certain investment banking services to the Company and its affiliates from time to time for which our Investment Banking Division has received, and may receive, compensation, including having acted as financial advisor to the Company in connection with a proxy contest in connection with the Company's 2010 annual meeting of shareholders in June 2010; as joint bookrunner with respect to an offering of the Company's 3.625%% Senior Notes due 2015 (aggregate principal amount $500,000,000) and 5.000% Senior Notes due 2020 (aggregate principal amount $500,000,000) in June 2010; and as financial advisor to the Company in connection with the sale of its interest in its genetic testing business unit in September 2010. In addition, as publicly disclosed by the Company, on June 17, 2010, the Company entered into an accelerated share repurchase agreement with Goldman, Sachs & Co for the repurchase of $1 billion of Shares. We have provided certain investment banking services to the Parent and its affiliates from time to time for which our Investment Banking Division has received, and may receive, compensation, including having acted as financial advisor to Parent in connection with its acquisition of Chattem, Inc. in December 2009. We also may provide investment banking services to the Company, Parent and their respective affiliates in the future for which our Investment Banking Division may receive compensation.

        In connection with this opinion, we have reviewed, among other things, the Schedule TO, including the Offer to Purchase and related letter of transmittal contained therein; the Solicitation/Recommendation Statement of the Company to be filed on Schedule 14D-9 with the Securities and Exchange Commission on October 7, 2010, in the form approved by you on the date of this opinion; annual reports to shareholders and Annual Reports on Form 10-K of the Company for the five fiscal years ended December 31, 2009, December 31, 2008, December 31, 2007, December 31, 2006 and December 31, 2005; certain interim reports to shareholders and Quarterly Reports on Form 10-Q of the Company; annual reports to shareholders and Annual Reports on Form 20-F of Parent for the fiscal years ended December 31, 2009, December 31, 2008, December 31, 2007, December 31, 2006 and December 31, 2005; certain interim reports to shareholders and quarterly reports included in Reports on Form 6-K of Parent; certain other communications from the Company and Parent to their respective shareholders; certain publicly available research analyst reports for the Company and Parent; and certain financial analyses and forecasts for the Company, including management's forecasts (the "Forecasts") approved for our use by the Company, and certain adjustments thereto as reviewed and discussed by the Board of Directors of Company. We have also held discussions with members of the senior management of the Company regarding their assessment of the strategic rationale of Parent for, and the potential benefits for Parent of, the Transactions and the past and current business operations, financial condition and future prospects of the Company; reviewed the reported price and trading activity for the Shares; compared certain financial and stock market information for the Company and Parent with similar information for certain other companies the securities of which are publicly traded; reviewed the financial terms of certain recent business combinations in the biotechnology industry and in other industries; and performed such other studies and analyses, and considered such other factors, as we deemed appropriate.

        For purposes of rendering this opinion, we have relied upon and assumed, without assuming any responsibility for independent verification, the accuracy and completeness of all of the financial, legal, regulatory, tax, accounting and other information provided to, discussed with or reviewed by, us; and we do not assume any responsibility for any such information. In that regard, we have assumed with your consent that the Forecasts have been reasonably prepared on a basis reflecting the best currently available estimates and judgments of the management of the Company. We have not made an independent evaluation or appraisal of the assets and liabilities (including any contingent, derivative or other off-balance-sheet assets and liabilities) of the Company, Parent or any of their respective subsidiaries and we have not been furnished with any such evaluation or appraisal.

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        Our opinion does not address the relative merits of the Transactions as compared to any strategic alternatives that may be available to the Company; nor does it address any legal, regulatory, tax or accounting matters. This opinion addresses only the adequacy from a financial point of view, as of the date hereof, of the Consideration proposed to be paid to the holders of Shares (other than the Offeror and any of its affiliates) pursuant to the Offer. We do not express any view on, and our opinion does not address, the fairness, from a financial point of view, of the Consideration or any other term or aspect of the Transactions. In addition, we do not express any view on, and our opinion does not address, the adequacy of the Consideration or any other term or aspect of the Transactions to, or any consideration received in connection therewith by, Offeror and any of its affiliates, the holders of any other class of securities, creditors, or other constituencies of the Company; nor as to the adequacy or fairness of the amount or nature of any compensation to be paid or payable to any of the officers, directors or employees of the Company, or class of such persons in connection with the Transactions, whether relative to the Consideration proposed to be paid to the holders of Shares pursuant to the Offer or otherwise. We are not expressing any opinion as to the prices at which the Shares will trade at any time. Our opinion is necessarily based on economic, monetary, market and other conditions as in effect on, and the information made available to us as of, the date hereof and we assume no responsibility for updating, revising or reaffirming this opinion based on circumstances, developments or events occurring after the date hereof. Our advisory services and the opinion expressed herein are provided for the information and assistance of the Board of Directors of the Company in connection with its consideration of the Offer and such opinion does not constitute a recommendation as to whether or not any holder of Shares should tender such Shares in connection with the Offer or any other matter. This opinion has been approved by a fairness committee of Goldman, Sachs & Co.

        Based upon and subject to the foregoing, it is our opinion that, as of the date hereof, the Consideration proposed to be paid to the holders of Shares (other than the Offeror and any of its affiliates) pursuant to the Offer is inadequate from a financial point of view to such holders.

Very truly yours,

/s/ Goldman, Sachs & Co.
(GOLDMAN, SACHS & CO.)

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QuickLinks

Item 1. Subject Company Information.
Item 2. Identity and Background of Filing Person.
Item 3. Past Contacts, Transactions, Negotiations and Agreements.

Item 4. The Solicitation or Recommendation.

Genzyme Confirms Receipt of Unsolicited Proposal

Item 5. Person/Assets, Retained, Employed, Compensated or Used.
Item 6. Interest in Securities of the Subject Company.
Item 7. Purpose of the Transaction and Plans or Proposals.
Item 8. Additional Information.

Item 9. Exhibits.

SIGNATURE

Annex A

Annex B

EX-99.(A)(1)

Exhibit (a)(1)

For Immediate Release	Media Contact:	Investor Contact:
October 7, 2010	Bo Piela	Patrick Flanigan
	(617) 768-6579	(617) 768-6563

Genzyme Board Unanimously Rejects Sanofi-Aventis Tender Offer

Recommends that Shareholders Not Tender Their Shares

Cambridge, MA — Genzyme Corp. (NASDAQ: GENZ) announced today that its board of directors has voted unanimously to reject the unsolicited $69.00 per share tender offer from Sanofi-Aventis, and the board recommends that Genzyme shareholders not tender their shares to Sanofi-Aventis pursuant to the offer. The board considered the following factors, among others, when making its recommendation:

·The offer is based on identical financial terms to two previous unsolicited proposals submitted by Sanofi-Aventis, both of which were rejected by the board.  The board remains unanimously resolute in its belief that the offer price of $69.00 per share is inadequate and opportunistic, substantially undervalues the company, fails to recognize the company’s plan to increase shareholder value, and is not in the best interests of Genzyme or its shareholders.

·The offer fails to compensate shareholders for the value of Genzyme’s existing business, which delivered compound annual revenue growth of 23 percent from 2002-2009. This business includes a unique and longstanding leadership position in the orphan-drug market; 12 market-leading products with durable revenue streams; and a long history of research and development productivity and success.

·The offer fails to recognize the value-creation impact of the company’s five-point plan. Under this plan, Genzyme is focusing on its core business and working to establish operational excellence in manufacturing; capitalizing on near-term growth drivers; divesting non-core businesses; reducing operating costs and improving margins; and optimizing its capital structure. Genzyme has made significant progress in implementing this plan, and the board believes that—given the opportunity to fully execute the plan—the company has the potential to generate substantially more value for shareholders than the offer price. The company also has an opportunity to further deploy its substantial prospective free cash flow to maximize value for shareholders.

·The offer fails to reflect Genzyme’s valuable late-stage pipeline, which includes three breakthrough products that are expected to be launched by the end of 2013. Foremost among these products is alemtuzumab, a potentially transformative therapy for multiple sclerosis. Phase 3 clinical trial results for this drug will be available in the middle of next year. Based on the robust clinical results reported to date from the phase 2 study, and the possibility for once yearly dosing, alemtuzumab has the potential to capture a material share of a global MS market that is projected to reach $14 billion when the product is first launched in 2012, offering an exciting revenue opportunity that will result in significant value for shareholders.

·The offer price does not adequately compensate Genzyme’s shareholders for the strategic importance and financial benefit to Sanofi-Aventis of a potential transaction with Genzyme.

The full basis for the board’s recommendation is set forth in a Solicitation/Recommendation Statement on Schedule 14D-9, which was filed by Genzyme today with the Securities and Exchange Commission.

Genzyme’s board and management are initiating a program to communicate with shareholders regarding the intrinsic value of the company. On October 14, Genzyme will hold an Analyst and Investor meeting in New York to provide a financial outlook, an update on its progress in executing its shareholder value plan, and other pertinent information. The event will be web cast on the investor events section of www.genzyme.com. Details of the meeting will be announced separately. On October 21, following the release of its third-quarter earnings results, the company will begin a series of meetings with shareholders.

Genzyme’s financial advisors are Credit Suisse and Goldman, Sachs & Co., and its legal advisor is Ropes & Gray LLP. The legal advisor for Genzyme’s independent directors is Wachtell, Lipton, Rosen & Katz.

About Genzyme

One of the world’s leading biotechnology companies, Genzyme is dedicated to making a major positive impact on the lives of people with serious diseases. Since 1981, the company has grown from a small start-up to a diversified enterprise with more than 12,000 employees in locations spanning the globe and 2009 revenues of $4.5 billion. In 2010, Genzyme was named to the Fortune 500.

With many established products and services helping patients in 100 countries, Genzyme is a leader in the effort to develop and apply the most advanced technologies in the life sciences. The company’s products and services are focused on rare inherited disorders, kidney disease, orthopaedics, cancer, transplant, and immune disease. Genzyme’s commitment to innovation continues today with a substantial development program focused on these fields, as well as cardiovascular disease, neurodegenerative diseases, and other areas of unmet medical need.

This press release contains forward-looking statements, including without limitation, statements regarding: Genzyme’s potential to generate substantially more value for shareholders than the offer price by executing its five-point plan and further deploying its prospective free cash flow; the prospects of its late-stage pipeline, including expected launch dates and market potential. These forward-looking statements are subject to a number of risks and uncertainties that could cause actual results to differ materially and adversely from those set forth in or implied by forward-looking statements. These risks and uncertainties include, but are not limited to: that Genzyme is unable to recognize value from any or all of it’s five-point plan due to manufacturing problems, clinical trial set-backs, or any other reason; that one or more of Genzyme’s late-stage pipeline products is unsuccessful; that the offer makes it more difficult for Genzyme to maintain relationships with employees, customers, suppliers and other business partners; that shareholder litigation brought in connection with the offer will result in significant defense, indemnification and liability costs; risks associated with development, manufacturing and commercialization of Genzyme’s products and product candidates; and other risks and uncertainties discussed in the Company’s filings with the SEC, including the information referred to under the heading “Risk Factors” section of the Company’s quarterly report on Form 10-Q for

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the quarter ended June 30, 2010. The Company does not undertake any obligation to update any forward-looking statements, which speak only as of the date of this press release.

Important Information

Genzyme has filed with the Securities and Exchange Commission a Solicitation/Recommendation Statement on Schedule 14D-9. Genzyme shareholders are advised to read the company’s Solicitation/Recommendation Statement on Schedule 14D-9 because it contains important information. Shareholders may obtain a free copy of the Solicitation/Recommendation Statement on Schedule 14D-9, as well as any other documents filed by Genzyme in connection with the tender offer by Sanofi-Aventis, free of charge at the SEC’s website at http://www.sec.gov.  In addition, investors and security holders can obtain free copies of these documents from Genzyme by directing a request to Genzyme at 500 Kendall Street, Cambridge, MA 02142, Attention: Shareholder Relations Department, or by calling 617-252-7500 and asking for the Shareholder Relations Department.

Genzyme’s press releases and other company information are available at www.genzyme.com and by calling Genzyme’s investor information line at 1-800-905-4369 within the United States or 1-678-999-4572 outside the United States.

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EX-99.(A)(2)

Exhibit (a)(2)

October 7, 2010

Dear Fellow Genzyme Shareholders:

On October 4, 2010, Sanofi-Aventis (Sanofi) launched an unsolicited tender offer (the Offer) to acquire your shares of common stock of Genzyme Corporation (Genzyme, or the Company) for $69.00 per share in cash, a price that is less than the closing price of $70.88 on October 1, 2010.  This formal Offer follows Sanofi’s July 29, 2010 and August 29, 2010 unsolicited, non-binding proposals to acquire your company for $69.00 per share, which your Board previously unanimously rejected.

Your Board of Directors reviewed the Offer together with the Company’s management and legal and financial advisors.  After careful consideration, the Board unanimously determined that the Offer, which is based on financial terms identical to the two previous unsolicited proposals submitted by Sanofi, continues to be inadequate and opportunistic, fails to recognize the Company’s plan for substantial value creation, substantially undervalues the Company relative to its intrinsic value, and is not in the best interests of Genzyme or its shareholders.

Therefore, your Board of Directors unanimously recommends that you reject the Offer and NOT tender your shares to Sanofi.

The Board’s rejection of Sanofi’s offer is based on numerous factors detailed in the enclosed Schedule 14D-9, including:

·Sanofi’s $69.00 per share Offer fails to compensate the company’s shareholders for the value of the company’s unique and industry-leading franchise

·Sanofi’s opportunistic Offer fails to recognize the substantial value creation potential of the Company’s previously announced five-point plan for shareholder value creation, and would deprive the Company’s shareholders of the opportunity to have the Company further deploy its substantial prospective free cash flow to maximize value for shareholders

·The Offer does not reflect Genzyme’s valuable late-stage pipeline, including three breakthrough products that are expected to be launched by 2013

·The Offer price does not adequately compensate Genzyme’s shareholders for the strategic importance and financial benefit to Sanofi of a potential transaction with Genzyme

Genzyme’s board has recommended that management embark on a program to communicate with shareholders regarding the intrinsic value of the Company.  In the coming days, Genzyme plans to hold an Analyst and Investor meeting to provide an updated financial outlook and other pertinent information.  The event will be webcast on the investor events section of www.genzyme.com.  Details of the meeting will be announced separately.

The enclosed Schedule 14D-9 contains a detailed description of the factors your board of directors considered in making its recommendation.  We urge you to read the enclosed Schedule 14D-9 carefully and to participate in the Company’s upcoming webcast in order to make a fully informed decision regarding your Genzyme shares.  If you have questions or need assistance, please call our information agent, Innisfree M&A Incorporated, toll-free at 888-750-5835.

We greatly appreciate your continued support and encouragement.

Sincerely,

/s/ Henri A. Termeer	/s/ Robert J. Carpenter
Henri A. Termeer	Robert J. Carpenter
Chief Executive Officer	Lead Independent Director
Chairman of the Board

EX-99.(A)(5)

Exhibit (a)(5)

UNITED STATES DISTRICT COURT
DISTRICT OF MASSACHUSETTS

JERRY L. & MENA M. MORELOS REVOCABLE TRUST, On Behalf Of Itself and All Others Similarly Situated,	) ) )	No.
	)
Plaintiff,	)	CLASS ACTION
	)
vs.	)
	)	SHAREHOLDER COMPLAINT BASED
HENRI A. TERMEER, MICHAEL S.	)	UPON SELF-DEALING AND BREACH OF
WYZGA, ROBERT J. CARPENTER,	)	FIDUCIARY DUTY
CHARLES L. COONEY, DOUGLAS A.	)
BERTHIAUME, GAIL K. BOUDREAUX,	)
ROBERT J. BERTOLINI, VICTOR J. DZAU,	)
CONNIE MACK III, RICHARD F. SYRON,	)
RALPH V. WHITWORTH, STEVEN	)
BURAKOFF, ERIC ENDE, DENNIS M.	)
FENTON, GENZYME CORP., and SANOFI-	)
AVENTIS,	)
	)
Defendants	)
	)

SUMMARY OF THE ACTION

1.This is a stockholder class action brought by plaintiff on behalf of the holders of Genzyme Corporation (“Genzyme” or the “Company”) common stock against Genzyme, certain of its officers and directors, and Sanofi-Aventis (“Sanofi”). This action seeks to enjoin defendants from further breaching their fiduciary duties in their pursuit to sell Genzyme for inadequate consideration (the “Proposed Acquisition”).

2.The Proposed Acquisition is the result of an unfair and self-serving process that the Individual Defendants (as defined herein) undertook to find a willing party to indemnify them for their wrongdoing rather than seeking to maximize shareholder value.  The proposed consideration per share, which resulted from the unfair process, materially undervalues the Company and is unfair to its stockholders.

3.Genzyme is a global biotechnology company that is focused on rare genetic disease disorders, renal disease, orthopedics, cancer, transplant and immune disease, and diagnostic and predictive testing. Genzyme is protected from generic competition because its products and pipeline focus on extremely rare genetic diseases.

4.While the Company has an enviable product pipeline and current valuable products, under the direction of Genzyme Chief Executive Officer (“CEO”) defendant Henri A. Termeer (“Termeer”), the Company has experienced continuous problems with its manufacturing facilities, which led to a series of regulatory actions taken by the federal Food and Drug Administration (“FDA”). On February 27, 2009, the FDA sent the Company a warning letter over what federal regulators described as “significant objectionable conditions” at its Boston manufacturing plant. A few months later, the Company shut down its Boston plant after it was found to have a viral contamination.  Unsurprisingly, the market reacted negatively to these significant, but curable, problems.  The Company’s manufacturing problems pushed the Company’s stock from a high of $83.06 on August 15, 2008, to its lowest point in over five years of $47.81 in June 2010. Moreover, a federal securities fraud class action was filed against the Company and multiple shareholders filed shareholder derivative actions against the Company’s directors and certain of its officers relating to the manufacturing problems and the FDA warning letters.

5.Despite the Company’s long-term prospects, the Individual Defendants are desperate to sell now to extinguish significant liability from the shareholder derivative actions, by squeezing out Genzyme shareholders. As an added benefit to themselves, the Individual Defendants will receive valuable change-in-control payments, and/or secure prestigious and lucrative positions in the post-Proposed Acquisition company.

6.In addition, four of the directors are beholden to outside influences from activist investors.  Defendants Steven Burakoff (“Burakoff”), Eric Ende (“Ende”), Dennis M. Fenton (“Fenton”), and Ralph V. Whitworth (“Whitworth”) are all Board of Directors (“Board”) members that are conflicted because they were forced on the Board to pursue the interests of Relational Investors LLC (“Relational”) and Carl C. Icahn. These activist investors are concerned with their short term profits and not maximizing shareholder value.

7.In pursuing this unlawful plan to squeeze out Genzyme’s public shareholders through the implementation of a flawed process and at an unfair price, the Individual Defendants

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have breached their fiduciary duties of loyalty, due care, independence, good faith, and fair dealing, and Genzyme and Sanofi have aided and abetted Genzyme’s officers and directors’ breaches of fiduciary duties.

8.Because the Individual Defendants dominate and control the business and corporate affairs of Genzyme, they have available to them private corporate information concerning Genzyme’s assets, business, and future prospects. The Individual Defendants’ access to this nonpublic information creates an imbalance and disparity of knowledge and economic power between them and the public shareholders of Genzyme. Thus, it is inherently unfair for them to execute and pursue an agreement and plan of merger under which they will evade liability in the derivative action and reap disproportionate benefits to the exclusion of maximizing shareholder value.

9.To remedy and prevent further breaches of fiduciary duty and other misconduct, plaintiff seeks, inter alia: (i) injunctive relief preventing consummation of the Proposed Acquisition, unless and until the Company adopts and implements a procedure or process to obtain a transaction that provides the best possible terms for shareholders; (ii) a directive to the Individual Defendants to exercise their fiduciary duties to obtain a transaction which is in the best interests of Genzyme’s shareholders; (iii) rescission of, to the extent already implemented, any agreement and plan of merger; and (iv) injunctive relief preventing the Individual Defendants from entering into any preclusive terms in an agreement and plan of merger.

JURISDICTION AND VENUE

10.This Court has jurisdiction over all causes of action asserted herein pursuant to 28 U.S.C. §1332(a)(2) in that plaintiff and defendants are citizens of different states and the amount in controversy exceeds $75,000, exclusive of interest and costs. This action is not a collusive action designed to confer jurisdiction on a court of the United States that it would not otherwise have.

11.This Court has jurisdiction over each defendant named herein because each defendant is either a corporation that conducts business in and maintains operations in this

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District, or is an individual who has sufficient minimum contacts with this District so as to render the exercise of jurisdiction by the District courts permissible under traditional notions of fair play and substantial justice.

12.Venue is proper in this Court pursuant to 28 U.S.C. §1391(a) because: (i) Genzyme maintains its principal place of business in this District; (ii) one or more of the defendants either resides in or maintains executive offices in this District; (iii) a substantial portion of the transactions and wrongs complained of herein, including the defendants’ primary participation in the wrongful acts detailed herein, and aiding and abetting and conspiracy in violation of fiduciary duties owed to Genzyme, occurred in this District; and (iv) defendants have received substantial compensation in this District by doing business here and engaging in numerous activities that had an effect in this District.

PARTIES

13.Plaintiff Jerry L. & Mena M. Morelos Revocable Trust is a shareholder of Genzyme. Plaintiff is a citizen of New Mexico.

14.Defendant Termeer is Genzyme’s Chief Executive Officer and has been since December 1985; Chairman of the Board and has been since May 1988; and President and a director and has been since October 1983. Defendant Termeer is a citizen of Massachusetts.

15.Defendant Michael S. Wyzga (“Wyzga”) is Genzyme’s Executive Vice President, Finance and has been since May 2003 and Chief Financial Officer and has been since July 1999. Wyzga was also Genzyme’s Chief Accounting Officer from January 1999 to November 2008; Senior Vice President, Finance from July 1999 to May 2003; Senior Vice President, Corporate Controller from January 1999 to July 1999; and Vice President and Corporate Controller from February 1998 to January 1999. Defendant Wyzga is a citizen of Massachusetts.

16.Defendant Robert J. Carpenter (“Carpenter”) is a Genzyme director and has been since 1994. Defendant Carpenter is a citizen of Massachusetts.

17.Defendant Charles L. Cooney (“Cooney”) is Genzyme director and has been since 1983. Defendant Cooney is a citizen of Massachusetts.

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18.Defendant Douglas A. Berthiaume (“Berthiaume”) is a Genzyme director and has been since 1988. Defendant Berthiaume is a citizen of Massachusetts.

19.Defendant Gail K. Boudreaux (“Boudreaux”) is a Genzyme director and has been since 2004. Defendant Boudreaux is a citizen of Illinois.

20.Defendant Robert J. Bertolini (“Bertolini”) is a Genzyme director and has been since December 2009. Defendant Bertolini is a citizen of New Jersey.

21.Defendant Victor J. Dzau (“Dzau”) is a Genzyme director and has been since 2000. Defendant Dzau is a citizen of North Carolina.

22.Defendant Connie Mack III (“Mack”) is a Genzyme director and has been since 2001. Defendant Mack is a citizen of Florida.

23.Defendant Richard F. Syron (“Syron”) is a Genzyme director and has been since 2006. Defendant Syron is a citizen of Massachusetts.

24.Defendant Whitworth is a Genzyme director and has been since April 2010. Defendant Whitworth is a citizen of California.

25.Defendant Burakoff is a Genzyme director and has been since June 2010. Defendant Burakoff is citizen of New York.

26.Defendant Ende is a Genzyme director and has been since June 2010. Defendant Ende is a citizen of Florida.

27.Defendant Dennis M. Fenton (“Fenton”) is a Genzyme director and has been since June 2010. Defendant Fenton is a citizen of California.

28.Defendant Genzyme Corp. (“Genzyme”) is a Massachusetts biotechnology company with a broad product and service portfolio focused on rare genetic disease disorders, renal disease, orthopedics, cancer, transplant and immune disease, and diagnostic and predictive testing. Defendant Genzyme is a citizen of Massachusetts.

29.Defendant Sanofi is a French diversified global pharmaceutical company with a portfolio of diabetes drugs, vaccines, a broad range of consumer healthcare products, and research focused on biological products. Defendant Sanofi is a citizen of France.

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30.The defendants named above in ¶¶14-27 are sometimes collectively referred to herein as the “Individual Defendants.”

THE INDIVIDUAL DEFENDANTS’ FIDUCIARY DUTIES

31.Under Massachusetts law, in any situation where the directors of a publicly traded corporation undertake a transaction that will result in either: (i) a change in corporate control; or (ii) a break up of the corporation’s assets, the directors have an affirmative fiduciary obligation to obtain the highest value reasonably available for the corporation’s shareholders, including a significant premium at the highest price attainable in the market.  To diligently comply with these duties, neither the directors nor the officers may take any action that:

(a)adversely affects the value provided to the corporation’s shareholders;

(b)will discourage, inhibit or deter alternative offers to purchase control of the corporation or its assets;

(c)contractually prohibits themselves from complying with their fiduciary duties;

(d)will otherwise adversely affect their duty to secure the best value reasonably available under the circumstances for the corporation’s shareholders; and/or

(e)will provide the directors and/or officers with preferential treatment at the expense of, or separate from, the public shareholders.

32.In accordance with their duty of loyalty, the Individual Defendants, as directors and/or officers of Genzyme, are obligated under Massachusetts law to refrain from:

(a)participating in any transaction where the directors’ or officers’ loyalties are divided;

(f)participating in any transaction where the directors or officers receive, or are entitled to receive, a personal financial benefit not equally shared by the public shareholders of the corporation; and/or

(g)unjustly enriching themselves at the expense or to the detriment of the public shareholders.

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33.The Individual Defendants, separately and together, in connection with the Proposed Acquisition, are knowingly or recklessly violating their fiduciary duties and aiding and abetting such breaches, including their duties of loyalty, good faith and independence owed to plaintiff and other public shareholders of Genzyme.

34.Certain of the Individual Defendants stand on both sides of the Proposed Acquisition, are engaging in self-dealing, are obtaining for themselves personal benefits, including personal financial benefits not shared equally by plaintiff or the Class (as defined herein). Certain Genzyme executives are also attempting to retain their prestigious and lucrative positions and compensation at the post-Proposed Acquisition company. The Board is seeking to extinguish the liability it faces in the derivative actions. Accordingly, the Proposed Acquisition will benefit the Individual Defendants in significant ways not shared with Class members. As a result of the Individual Defendants’ self-dealing and divided loyalties, neither plaintiff nor the Class will receive adequate or fair value for their Genzyme common stock in the Proposed Acquisition.

35.Because the Individual Defendants are knowingly or recklessly breaching their duties of loyalty, good faith, and independence in connection with the Proposed Acquisition, the burden of proving the inherent or entire fairness of the Proposed Acquisition, including all aspects of its negotiation, structure, price, and terms, is placed upon defendants as a matter of law.

THE DERIVATIVE ACTIONS

36.Defendants Berthiaume, Boudreaux, Bertolini, Carpenter, Cooney, Dzau, Mack, and Syron are Board members and are defendants in various shareholder derivative actions. In December 2009, two shareholder derivative actions were filed for Genzyme’s benefit in the United States District Court for the District of Massachusetts. In January 2010, a shareholder derivative action was filed in Massachusetts Superior Court, which was followed by two other shareholder derivative actions.  The derivative actions are based on allegations that the Board and certain executive officers breached their fiduciary duties by making improper statements

7

regarding manufacturing issues, compliance with current good manufacturing practices, ability to meet product demand, expected revenue growth, and approval of Lumizyme. The complaints also allege that the Board and executive officers breached their fiduciary duty of loyalty by using this knowledge of material, non-public information to improperly sell Genzyme stock that they personally held.

37.The derivative actions are best summed up in a November 17, 2009 article on thestreet.com. The article state Termeer was the worst biotechnology company CEO this year and that it “wasn’t even close ... given Termeer’s epic mismanagement of Genzyme this year.” Termeer’s mismanagement led to “a never-ending series of regulatory and manufacturing snafus [that] has forced the company to delay drug approvals and launches, temporarily shutter a major manufacturing plant due to a viral contamination, write off millions of dollars in product inventory and poison its relationship with the U.S. Food and Drug Administration [to the point that regulators have taken an active role in helping Genzyme’s competitors.”

38.The blame does not lie solely upon Termeer. The Board, which consists of several directors with scientific and manufacturing backgrounds, backed Termeer’s reckless mismanagement of the Company. Yet, despite the scientific and manufacturing knowledge at its disposal, the Board backed Termeer’s decision to manufacture complicated drugs in a run-down, dirty manufacturing facility in Allston, Massachusetts, referred to as the Allston Landing facility.

39.Genzyme’s troubles with the facility began during October 2008, when the FDA issued a warning letter to the Company following an inspection.  Termeer and the Board, however, concealed the warning letter from shareholders until March 2009. When they finally disclosed the warning letter’s existence, Termeer and his fellow officers and directors attempted to whitewash the FDA’s concerns, which they vaguely described as issues related to “microbiological monitoring and mainly drug substance, equipment maintenance as well as certain process controls at the manufacturing facility.” The FDA’s actual warnings were somewhat more detailed and severe.

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40.According to The Wall Street Journal, who received a redacted copy of the FDA’s warning letter, the FDA much more accurately described its concerns as “‘significant deviations from current good manufacturing practice.’”  Further, “‘[t]he deficiencies described in [the warning] letter are indicative of [Genzyme’s] quality control unit’s failure to fulfill its responsibility to assure the identity, strength, quality and purity of [the Company’s] drug products and drug substances.’” In particular, the FDA warned Genzyme to stop using freezers and other equipment “beyond their stated life expectancy”; and to perform proper equipment maintenance. These warnings went unheeded.

41.Genzyme’s uncorrected sloppy manufacturing practices had severe consequences, which include the FDA’s refusal to approve Lumizyme, a drug that the Company is currently attempting to market in the United States for the treatment of Pompe disease. On March 2, 2009, Genzyme disclosed that the FDA was withholding approval for the drug pending the completion of corrective actions to address Genzyme’s deficient manufacturing processes. And recently on November 16, 2009, Genzyme disclosed that the FDA was continuing to withhold approval because the Company’s sloppy manufacturing process remained uncorrected.  This FDA approval delay has cost the Company millions of dollars in delayed revenues and driven the Company’s stock price down to levels not seen in over five years.

42.Genzyme’s sloppy manufacturing process also contributed to the viral infection of several bioreactors at the Allston Landing facility. As a result of the infection, during June 2009, Genzyme was forced to shutdown the facility in order to sanitize it. Although Termeer and his fellow officers and directors have been unable to determine the specific source of the viral contamination, they admit that the virus contributed to manufacturing slowdowns during 2008. In other words, Termeer and his cohorts allowed the Allston Landing facility to be infected for over a year before they acted to correct the problem.

43.The June 2009 Allston Landing facility shutdown caused a shortage of the Company’s Cerezyme and Fabrazyme drugs. This shortage, in turn, has resulted in millions of dollars in losses for the Company through lost drug sales. As a result of these losses, Sanofi is

9

attempting to acquire the Company while its stock is depressed. And while the Individual Defendants are willing to sell the Company in order to extinguish their liability for their breaches of fiduciary duties.

THE PROPOSED ACQUISITION

44.On July 23, 2010, The New York Times published an article titled “Sanofi Said to Have Offered to Make a Bid for Genzyme.” The article stated:

Sanofi-Aventis has made an informal takeover approach to Genzyme, a person briefed on the matter said on Friday, as the French drug maker seeks to bolster its biotechnology offerings.

* * *

Genzyme would bring Sanofi an attractive portfolio of drugs that treat rare conditions like Fabry disease. Because of their relative complexity, Genzyme’s products fetch high prices. Cerezyme, a treatment for Gaucher’s disease and one of the company’s main products, has garnered more than $1 billion in annual sales, though it is used to treat fewer than 6,000 patients.

45.In a July 26, 2010 article on Bloomberg.com, Sven Borho, an analyst with OrbiMed Advisors stated that “if two or three companies get involved in bidding, the $80s are achieved really easily.... There are so few good assets out there, and this is one of the more promising assets.” In addition to Sanofi, the Bloomberg.com article stated that GlaxoSmithKline Plc recently made an overture to Genzyme.  And other reports have claimed that Johnson & Johnson is also interested in pursuing an acquisition of Genzyme.

46.Moreover, the premium being reported by reliable sources offers a minimal benefit at best. On July 28, 2010, The New York Times DealBook stated that people briefed on the matter indicated the Proposed Acquisition would be at a price of $70 per share.  Also, according to a Bloomberg Businessweek article, Sanofi’s Board has only authorized an offer of $70 per share.  While the Proposed Acquisition at that price is ostensibly at a premium, the Company stock price recently traded at more than $83 prior to the manufacturing problems caused by the Individual Defendants, and as recently as January 2010, Relational stated that it believes Genzyme could achieve a stock price as high as $90.

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47.The premium being offered in the Proposed Acquisition is only 29.22% higher than Genzyme’s closing price on July 22, 2010, the day before the information about Sanofi’s bid became public. This premium pales in comparison to other premiums paid for pharmaceutical companies, even though they lacked Genzyme’s potential. For instance, in May, Japanese drug maker Astellas Pharma Inc. agreed to buy OSI Pharmaceuticals Inc. for a 68% premium. In a similar biotechnology deal, AstraZeneca Plc agreed to acquire MedImmune Inc. in 2007 at a 70% premium. And, in 2008, Eli Lilly & Co. agreed to buy ImClone Systems Inc. for a 73% premium. None of these Company’s products and pipeline can compare to Genzyme’s. Yet, they garnered premiums more than double that being offered in the Proposed Acquisition.

48.Despite the Company’s positive future, the Board entered the Proposed Acquisition attempting to sell the Company now, even though its stock has not yet fully recovered from the Individual Defendants’ mismanagement and lax oversight.

THE UNFAIR AND INADEQUATE PROCESS

49.In order to meet their fiduciary duties, the Individual Defendants are obligated to explore transactions that will maximize shareholder value, and not structure a preferential deal for themselves.  Due to the Individual Defendants’ eagerness to enter into a transaction with Sanofi, they failed to implement a process to obtain the maximum price for Genzyme’s shareholders.

50.As a result of defendants’ conduct, Genzyme’s public stockholders have been and will continue to be denied the fair process and arm’s-length negotiated terms to which they are entitled in a sale of their Company.

SELF-DEALING

51.Because Individual Defendants dominate and control the business and corporate affairs of Genzyme and have access to material nonpublic information concerning Genzyme’s financial condition and business prospects.  Thus, there exists an imbalance and disparity of available knowledge and economic power between them and the public shareholders of Genzyme. Therefore, it is inherently unfair for the Individual Defendants to execute and pursue

11

any Proposed Acquisition agreement under which they will reap disproportionate benefits to the exclusion of obtaining the best value for shareholders. Instead, the Individual Defendants are disloyally placing their own interests first, and tailoring the terms and conditions of the Proposed Acquisition to meet their own personal needs and objectives.

52.The Genzyme Board has four members that are beholden to two formidable activist investors:  Carl C. Icahn and defendant Whitworth.  Defendants Burakoff, Ende, Whitworth, and Fenton all are incurably conflicted because their loyalties are divided between the Company and the persons and/or entities that had them placed on the Board.  Defendants Burakoff, Ende, Whitworth, and Fenton are responsible for representing the interests of their benefactors rather than the Company’s shareholders. Thus, defendants Burakoff, Ende, Whitworth, and Fenton are breaching their fiduciary duties by not acting in the best interests of all shareholders.

53.Rather than let the shareholders of Genzyme benefit from its strong financial performance, the Individual Defendants are seeking to sell the Company for their own benefit. By attempting to sell the Company, the Individual Defendants are trying to extinguish the significant liability they face in the derivative action. Thus, the Individual Defendants are acting for their benefit and to the detriment of the Class.

54.The Individual Defendants’ attempt to sell the Company is wrongful, unfair, and harmful to Genzyme’s public shareholders, and represents an effort by defendants to aggrandize their own financial position and interests at the expense of and to the detriment of Class members.  Specifically, defendants are attempting to deny plaintiff and the Class their shareholder rights via the sale of Genzyme through an unfair process. Accordingly, the Proposed Acquisition will benefit defendants at the expense of Genzyme’ shareholders.

55.In light of the foregoing, the Individual Defendants must, as their fiduciary obligations require:

·Withdraw their consent to the sale of Genzyme and allow the shares to trade freely – without impediments;

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·Act independently so that the interests of Genzyme’ public shareholders will be protected;

·Adequately ensure that no conflicts of interest exist between defendants’ own interests and their fiduciary obligation to maximize shareholder value or, if such conflicts exist, to ensure that all conflicts be resolved in the best interests of Genzyme’ public shareholders; and

·Solicit competing bids to assure that the Company’s shareholders are receiving the best reasonably obtainable value for their shares.

CLASS ACTION ALLEGATIONS

56.Plaintiff brings this action individually and as a class action pursuant to Federal Rule of Civil Procedure 23 on behalf of all holders of Genzyme stock who are being and will be harmed by defendants’ actions described herein (the “Class”). Excluded from the Class are defendants herein and any person, firm, trust, corporation, or other entity related to or affiliated with any defendant.

57.This action is properly maintainable as a class action.

58.The Class is so numerous that joinder of all members is impracticable. According to Genzyme’s United States Securities and Exchange Commission filings, there are more than 254.8 million shares of Genzyme common stock outstanding.

59.There are questions of law and fact which are common to the Class and which predominate over questions affecting any individual Class member.  The common questions include, inter alia, the following:

(a)whether the Individual Defendants have breached or are breaching their fiduciary duties of undivided loyalty, independence, or due care with respect to plaintiff and the other members of the Class in connection with the Proposed Acquisition;

(b)whether the Individual Defendants are engaging in self-dealing in connection with the Proposed Acquisition;

(c)whether the Individual Defendants have breached or are breaching any of their other fiduciary duties owed to plaintiff and the other members of the Class in connection with the Proposed Acquisition, including the duties of good faith, diligence, and fair dealing;

13

(d)whether Genzyme aided and abetted the Individual Defendants’ breaches of fiduciary duties;

(e)whether Sanofi aided and abetted the Individual Defendants’ breaches of fiduciary duties; and

(f)whether plaintiff and the other members of the Class would suffer irreparable injury were the transactions complained of herein consummated.

60.Plaintiff’s claims are typical of the claims of the other members of the Class and plaintiff does not have any interests adverse to the Class.

61.Plaintiff is an adequate representative of the Class, has retained competent counsel experienced in litigation of this nature and will fairly and adequately protect the interests of the Class.

62.The prosecution of separate actions by individual members of the Class would create a risk of inconsistent or varying adjudications with respect to individual members of the Class which would establish incompatible standards of conduct for the party opposing the Class.

63.Plaintiff anticipates that there will be no difficulty in the management of this litigation.  A class action is superior to other available methods for the fair and efficient adjudication of this controversy.

64.Defendants have acted and are acting on grounds generally applicable to the Class with respect to the matters complained of herein, thereby making appropriate the relief sought herein with respect to the Class as a whole.

FIRST CAUSE OF ACTION

Claim for Breach of Fiduciary Duties Against the Individual Defendants

65.Plaintiff incorporates by reference and realleges each and every allegation contained above, as though fully set forth herein.

66.The Individual Defendants have violated their fiduciary duties of care, loyalty, good faith, and independence owed to the public shareholders of Genzyme and have acted to put their personal interests ahead of the interests of Genzyme’s shareholders.

14

67.By the acts, transactions, and courses of conduct alleged herein, defendants, individually and acting as a part of a common plan, are attempting to unfairly deprive plaintiff and other members of the Class of the true value inherent in and arising from Genzyme.

68.The Individual Defendants are violating their fiduciary duties by attempting to sell the Company without regard to the effect of the Proposed Acquisition on Genzyme’s shareholders.

69.As demonstrated by the allegations above, the Individual Defendants are failing to exercise the care required, and breached their duties of loyalty, good faith, and independence owed to the shareholders of Genzyme because, among other reasons, they are ignoring or have not protected against the numerous conflicts of interest among members of the Board and the Company’s management.

70.Because the Individual Defendants dominate and control the business and corporate affairs of Genzyme, and have access to private corporate information concerning Genzyme’s assets, business, and future prospects, there exists an imbalance and disparity of knowledge and economic power between them and the public shareholders of Genzyme which makes it inherently unfair for them to pursue and recommend any proposed transaction wherein they will reap disproportionate benefits to the exclusion of maximizing shareholder value.

71.By reason of the foregoing acts, practices, and course of conduct, the Individual Defendants are failing to exercise ordinary care and diligence in the exercise of their fiduciary obligations toward plaintiff and the other members of the Class.

72.Unless enjoined by this Court, the Individual Defendants will continue to breach their fiduciary duties owed to plaintiff and the Class, and may consummate the Proposed Acquisition which will exclude the Class from its fair share of Genzyme’s valuable assets and operations, and/or benefit defendants in the unfair manner complained of herein, all to the irreparable harm of the Class.

15

73.The Individual Defendants are engaging in self-dealing, are not acting in good faith toward plaintiff and the other members of the Class, and have breached and are breaching their fiduciary duties to the members of the Class.

74.As a result of the Individual Defendants’ unlawful actions, plaintiff and the other members of the Class will be irreparably harmed in that they will not receive their fair portion of the value of Genzyme’s assets and operations. Unless the Proposed Acquisition is enjoined by the Court, the Individual Defendants will continue to breach their fiduciary duties owed to plaintiff and the members of the Class, will not engage in arm’s-length negotiations on the Proposed Acquisition terms and may consummate the Proposed Acquisition on unfair terms and through an unfair process, all to the irreparable harm of the members of the Class.

75.Plaintiff and the members of the Class have no adequate remedy at law.  Only through the exercise of this Court’s equitable powers can plaintiff and the Class be fully protected from the immediate and irreparable injury which defendants’ actions threaten to inflict.

SECOND CAUSE OF ACTION

Claim for Aiding and Abetting Breaches of Fiduciary Duty Against Genzyme

76.Plaintiff incorporates by reference and realleges each and every allegation contained above, as though fully set forth herein.

77.The Individual Defendants owed to plaintiff and the members of the Class certain fiduciary duties as fully set out herein.

78.By committing the acts alleged herein, the Individual Defendants breached their fiduciary duties owed to plaintiff and the members of the Class.

79.Genzyme colluded in or aided and abetted the Individual Defendants’ breaches of fiduciary duties, and is an active and knowing participant in the Individual Defendants’ breaches of fiduciary duties owed to plaintiff and the members of the Class.

80.Plaintiff and the members of the Class shall be irreparably injured as a direct and proximate result of the aforementioned acts.

16

THIRD CAUSE OF ACTION

Claim for Aiding and Abetting Breaches of Fiduciary Duty Against Sanofi

81.Plaintiff incorporates by reference and realleges each and every allegation contained above as though fully set forth herein.

82. The Individual Defendants owed to plaintiff and the members of the Class certain fiduciary duties as fully set out herein.

83.By committing the acts alleged herein, the Individual Defendants breached their fiduciary duties owed to plaintiff and the members of the Class.

84.Defendant Sanofi colluded in or aided and abetted the Individual Defendants’ breaches of fiduciary duties, and was an active and knowing participant in the Individual Defendants’ breaches of fiduciary duties owed to plaintiff and the members of the Class.

85.Defendant Sanofi participated in the breach of the fiduciary duties by the Individual Defendants for the purpose of advancing its own interests. Defendant Sanofi obtained and will obtain both direct and indirect benefits from colluding in or aiding and abetting the Individual Defendants’ breaches. Defendant Sanofi will benefit, inter alia, from the acquisition of the Company at an inadequate and unfair price if the Proposed Acquisition is consummated.

86.Plaintiff and the members of the Class shall be irreparably injured as a direct and proximate result of the aforementioned acts.

PRAYER FOR RELIEF

WHEREFORE, plaintiff demands injunctive relief, in its favor and in favor of the Class and against defendants as follows:

A.Declaring that this action is properly maintainable as a class action;

B.Enjoining defendants, their agents, counsel, employees, and all persons acting in concert with them from consummating the Proposed Acquisition, unless and until the Company adopts and implements a procedure or process reasonably designed to enter into a merger agreement providing the best possible value for shareholders;

17

C.Directing defendants to exercise their fiduciary duties to commence a sale process that is reasonably designed to secure the best possible consideration for Genzyme and obtain a transaction which is in the best interests of Genzyme’s shareholders

D.Rescinding, to the extent already implemented, the Proposed Acquisition;

E.Imposition of a constructive trust, in favor of plaintiff and members of the Class, upon any benefits improperly received by defendants as a result of their wrongful conduct;

F.Awarding plaintiff the costs and disbursements of this action, including reasonable attorneys’ and experts’ fees; and

G.Granting such other and further equitable relief as this Court may deem just and proper.

Dated: August 11, 2010	By its attorneys,
	/s/ Theodore M. Hess-Mahan
	Theodore M. Hess-Mahan, BBO #557109
	thess-mahan@hutchingsbarsamian.com
	HUTCHINGS, BARSAMIAN,
	MANDELCORN & ZEYTOONIAN, LLP
	110 Cedar Street, Suite 250
	Wellesley Hills, MA 02481
	Phone: (781) 431-2231
	Fax: (781) 431-8726
	ROBBINS UMEDA LLP
	MARC M. UMEDA
	STEPHEN J. ODDO
	REBECCA A. PETERSON
	ARSHAN AMIRI
	600 B Street, Suite 1900
	San Diego, CA 92101
	Telephone: (619) 525-3990
	Facsimile : (619) 525-3991
	THE LAW OFFICES OF NICHOLAS
	KOLUNCICH III
	NICHOLAS KOLUNCICH III
	6501 Americas Parkway NE, Suite 820
	Albuquerque, NM 87110
	Telephone: (505) 881-2228
	Facsimile: (505) 881-4288
	Attorneys for Plaintiff Jerry L. & Mena M
	Morelos Revocable Trust

18

EX-99.(A)(6)

Exhibit (a)(6)

UNITED STATES DISTRICT COURT
DISCTRICT OF MASSACHUSETTS

BERNARD MALINA, individually and on behalf
of all others similarly situated,
	Civil Action No.
Plaintiff,
vs.
GENZYME CORPORATION, HENRI A.
TERMEER, DOUGLAS A. BERTHIAUME,
ROBERT J. BERTOLINI, GAIL K.
BOUDREAUX, ROBERT J. CARPENTER,
CHARLES L. COONEY, VICTOR J. DZAU,
ERIC ENDE, DENNIS M. FENTON, CONNIE
MACK III, RICHARD F. SYRON, and RALPH
V. WHITWORTH
Defendants.

CLASS ACTION COMPLAINT

Plaintiff, by his attorneys, alleges upon personal knowledge as to his own acts and upon information and belief as to all other matters, as follows:

NATURE OF THE ACTION

1.This is a stockholders’ class action lawsuit brought on behalf of the public stockholders of Genzyme Corporation (“Genzyme” or the “Company”) who have been, and continue to be, deprived of the opportunity to realize fully the benefits of their investment in the Company. The individual defendants, by the previous rejection of proposals by Sanofi-Aventist SA (“Sanofi”) to acquire the Company, did breach their fiduciary duties.

THE PARTIES

Plaintiff

2.Plaintiff, Bernard Malina, is and at all times relevant hereto has been a stockholder of Genzyme. Plaintiff is a citizen of New York.

The Company

3.Defendant Genzyme Corporation is a corporation organized and existing under the laws of the State of Massachusetts. The Company maintains its principal offices at 500 Kendall Street, Cambridge, Massachusetts 02142.

Individual Defendants

4.Defendant Henri A. Termeer (“Termeer”) has served as a director and President of the Company since October 1983, as Chief Executive Officer since December 1985 and as Chairman of the Board since May 1988. According to Genzyme’s 2010 Proxy Statement, last year Mr. Termeer received $9,507,403 in total compensation from the Company. Mr. Termeer is a citizen of Massachusetts.

5.Defendant Douglas A. Berthiaume (“Berthiaume”) has served as director of the Company since 1988. According to Genzyme’s 2010 Proxy Statement, last year Mr. Berthiaume received $444,942 in total compensation from the Company. According to Genzyme’s 2010 Proxy Statement, last year Mr. Berthiaume received $444,942 in total compensation from the Company. Mr. Berthiaume is a citizen of Massachusetts.

6.Defendant Robert J. Bertolini (“Bertolini”) has served as a director of the Company since December 8, 2009. According to Genzyme’s 2010 Proxy Statement, last year (for less than one month of work) Mr. Bertolini received $264,835 in total compensation from the Company. Mr. Bertolini is a citizen of New Jersey.

2

7.Defendant Gail K. Boudreaux (“Boudreaux”) has served as a director of the Company since 2004. According to Genzyme’s 2010 Proxy Statement, last year Ms. Boudreaux received $417,442 in total compensation from the Company. Ms. Boudreaux is a citizen of Illinois.

8.Defendant Robert J. Carpenter (“Carpenter”) has served as a director of the Company since 1994. According to Genzyme’s 2010 Proxy Statement, last year Mr. Carpenter received $415,942 in total compensation from the Company. Mr. Carpenter is a citizen of Massachusetts.

9.Defendant Charles L. Cooney (“Cooney”) has served as a director of the Company since 1983. According to Genzyme’s 2010 Proxy Statement, last year Mr. Cooney received $424,442 in total compensation from the Company. Mr. Cooney is a citizen of Massachusetts.

10.Defendant Victor J. Dzau (“Dzau”) has served as a director of the Company since 2000. According to Genzyme’s 2010 Proxy Statement, last year Mr. Dzau received $412,942 in total compensation from the Company. Mr. Dzau is a citizen of North Carolina.

11.Defendant Eric Ende (“Ende”) has served as a director of the Company since 2010. Mr. Ende is a citizen of Florida.

12.Defendant Dennis M. Fenton (“Fenton”) has served as a director of the Company since 2010. Mr. Fenton is a citizen of California.

13.Defendant Connie Mack III (“Mack”) has served as a director of the Company since 2001. According to Genzyme’s 2010 Proxy Statement, last year Mr. Mack received $421,942 in total compensation from the Company. Mr. Mack is a citizen of Florida.

3

14.Defendant Richard F. Syron (“Syron”) has served as a director of the Company since 2006. According to Genzyme’s 2010 Proxy Statement, last year Mr. Syron received $417,942 in total compensation from the Company. Mr. Syron is a citizen of Massachusetts.

15.Defendant Ralph V. Whitworth (“Whitworth”) has served as a director of the Company since April 14 2010. Mr. Whitworth is a citizen of California.

16.Defendants Termeer, Berthiaume, Bertolini, Boudreaux, Burakoff, Carpenter, Cooney, Dzau, Ende, Fenton, Mack, Syron, and Whitworth (collectively the “Individual Defendants”), are in a fiduciary relationship with the Company, Plaintiff and the public stockholders of Genzyme.

17.The Individual Defendants, by reason of their corporate directorships and/or executive positions, are fiduciaries to and for the Company’s stockholders, which fiduciary relationship requires them to exercise their best judgment, and to act in a prudent manner and in the best interests of the Company’s stockholders.

18.Each Individual Defendant herein is sued individually as a conspirator and aider and abettor, as well as in his capacity as an officer and/or director of the Company, and the liability of each arises from the fact that each has engaged in all or part of the unlawful acts, plans, schemes, or transactions of which Plaintiff complains herein.

19.The Individual Defendants together with Genzyme are sometimes collectively referred to herein as “Defendants.”

JURISDICTION AND VENUE

20.This Court has jurisdiction over all causes of action asserted herein pursuant to 28 U.S.C. §1332(a)(1) in that plaintiff and defendants are citizens of different states and the amount in controversy exceeds $75,000, exclusive of interest and costs. This action is not a collusive

4

action designed to confer jurisdiction on a court of the United States that it would not otherwise have.

21.This Court has jurisdiction over each defendant named herein because each defendant is either a corporation that conducts business in and maintains operations in this District, or is an individual who has sufficient minimum contacts with this District so as to render the exercise of jurisdiction by the District courts permissible under traditional notions of fair play and substantial justice.

22.Venue is proper in this Court pursuant to 28 U.S.C. §1391(a) because: (i) Genzyme maintains its principal place of business in this District; (ii) one or more of the defendants either resides in or maintains executive offices in this District; (iii) a substantial portion of the transactions and wrongs complained of herein, including the defendants’ primary participation in the wrongful acts detailed herein, and aiding and abetting and conspiracy in violation of fiduciary duties owed to Genzyme, occurred in this District; and (iv) defendants have received substantial compensation in this District by doing business here and engaging in numerous activities that had an effect in this District.

CLASS ACTION ALLEGATIONS

23.Plaintiff brings this action, pursuant to Mass. R. Civ. P. 23, individually and as a class action on behalf of all shareholders of defendant Genzyme (except Defendants herein and any person, firm, trust, corporation or other entity related to or affiliated with any of the Defendants) or their successors in interest, who have been or will be adversely affected by the conduct of Defendants alleged herein (the “Class”).

24.This action is properly maintainable as a class action for the following reasons:

a.The Class of shareholders for whose benefit this action is brought is so numerous that joinder of all Class members is impracticable. As of June 3, 2010, there were

5

254,839,847 shares of Genzyme stock outstanding, owned by thousands of shareholders of record scattered throughout the United States.

b.There are questions of law and fact which are common to members of the Class and which predominate over any questions affecting any individual members. The common questions include, inter alia, the following:

i.whether one or more of the Defendants has engaged in a plan and scheme to enrich themselves at the expense of defendant Genzyme’s public stockholders;

ii.whether the Individual Defendants have breached their fiduciary duties owed by them to Plaintiff and members of the Class, and/or have aided and abetted in such breach, by virtue of their participation and/or acquiescence and by their other conduct complained of herein;

iii.whether the Individual Defendants have wrongfully failed and refused to seek a purchase of Genzyme at the highest possible price and, instead, have sought to entrench themselves for their benefit and to the detriment of Genzyme’s public stockholders;

iv.whether Plaintiff and the other members of the Class will be irreparably damaged by the transactions complained of herein; and

v.whether Defendants have breached or aided and abetted the breaches of the fiduciary and other common law duties owed by them to Plaintiff and the other members of the Class.

25.Plaintiff is committed to prosecuting this action and has retained competent counsel experienced in litigation of this nature. The claims of Plaintiff are typical of the claims of the other members of the Class and Plaintiff has the same interest as the other members of the

6

Class. Accordingly, Plaintiff is an adequate representative of the Class and will fairly and adequately protect the interests of the Class.

26.Plaintiff anticipates that there will not be any difficulty in the management of this litigation.

27.For the reasons stated herein, a class action is superior to other available methods for the fair and efficient adjudication of this action.

SUBSTANTIVE ALLEGATIONS

28.Defendant, Genzyme operates as a biotechnology company worldwide. It focuses on rare genetic disease disorders, renal diseases, orthopaedics, cancers, transplant and immune diseases, and diagnostic and predictive testing areas.

29.While it may have the potential to do great things in the future, the truth is that over the past 2 years the Company has struggled mightily with manufacturing and product development issues. As a result of these issues, the Company’s stock price has suffered tremendously, falling from a high of $83.25 per share on August 14, 2008, to a low $47.16 per share on June 9, 2010, just three weeks before the Sanofi takeover rumors started circulating.

30.In fact, in the year prior to July 1, 2010, Genzyme’s stock price never traded above $59.50 per share.

31.Irrespective of the Company’s struggles, on Monday, August 30, 2010, Genzyme issued a press released, filed with the SEC on Form 8-K, announcing that it had received and rejected a second offer by Sanofi to purchase the Company at $69 per share (approximately $18.5 million) (the “Second Offer”).

32.The Second Offer, which includes the same $69 per share price offer that Sanofi made on July 29, 2010, provides a 38% premium over the Genzyme’s price of $49.86 per share

7

on July 1, 2010, prior to any market speculation regarding Sanofi’s interest in purchasing the Company.

33.Irrespective of the Company’s struggles and Sanofi’s multiple offers and overtures, however, Genzyme has not been a cooperative negotiating partner. Indeed, the Company has rejected Sanofi’s overtures to engage in friendly negotiations designed to lead to a transaction.

34.Instead, the Individual Defendant’s have refused to engage in good faith negotiations with Sanofi and have compelled Sanofi to make its offers public and to consider a hostile takeover of the Company.

35.Defendants’ failure to properly consider and act upon Sanofi’s offers evidences their disregard for the premium being offered to Genzyme shareholders. By failing to properly pursue the offers, defendants are depriving plaintiff and the Class of the right to receive the maximum value for their shares.

36.No other parties have shown a legitimate interest in Genzyme. Thus, Defendants’ rejection of Sanofi’s offer will ensure their continued positions within the Company but deprive the Company’s public shareholders of the premium that Sanofi is prepared to pay, or of the enhanced premium that negotiation could provide.

37.Defendants owe fundamental fiduciary obligations to Genzyme’s stockholders to take all necessary and appropriate steps to maximize the value of their shares. In addition, the Individual Defendants have the responsibility to act independently so that the interests of the Company’s public stockholders will be protected and to consider properly all bona fide offers for the Company. Further, the directors of Genzyme must adequately ensure that no conflict of interest exists between the Individual Defendants’ own interests and their fiduciary obligations to

8

maximize stockholder value or, if such conflicts exist, to insure that all such conflicts will be resolved in the best interests of the Company’s stockholders.

38.Because defendants dominate and control the business and corporate affairs of Genzyme and because they are in possession of private corporate information concerning Genzyme’s assets, businesses and future prospects, there exists an imbalance and disparity of knowledge of economic power between defendants and the public stockholders of Genzyme. This discrepancy makes it grossly and inherently unfair for defendants to entrench themselves at the expense of Genzyme’s stockholders.

39.The Individual Defendants have breached their fiduciary and other common law duties owed to plaintiff and other members of the Class in that they have not and are not exercising independent business judgment and have acted and are acting to the detriment of the Class.

40.Plaintiff seeks preliminary and permanent injunctive relief and declaratory relief preventing defendants from inequitably and unlawfully depriving plaintiff and the Class of their rights to realize a full and fair value for their stock at a premium over the market price, by unlawfully entrenching themselves in their positions of control, and to compel defendants to carry out their fiduciary duties to maximize shareholder value.

41.Only through the exercise of this Court’s equitable powers can plaintiff be fully protected from the immediate and irreparable injury which defendants’ actions threaten to inflict.

42.Unless enjoined by the Court, Defendants will continue to breach their fiduciary duties owed to plaintiff and the members of the Class, and/or aid and abet and participate in such breaches of duty, and will prevent the sale of Genzyme at a substantial premium, all to the irreparable harm of plaintiff and other members of the Class.

9

43.Plaintiff and the Class have no adequate remedy at law.

WHEREFORE, Plaintiff demands judgment as follows:

a.Declaring that this action may be maintained as a class action;

b.Ordering by affirmative injunction that the Individual Defendants fulfill their fiduciary duties to plaintiff and the other members of the Class by:

i.Cooperating fully with any entity or person, including Sanofi, having a bona fide interest in proposing any transactions that would maximize shareholder value, including, but not limited to, a merger or acquisition of Genzyme;

ii.Adequately ensuring that no conflicts of interest exist between the Individual Defendants’ own interests and their fiduciary obligation to maximize shareholder value or, in the event such conflicts exist, to ensure that all conflicts of interest are resolved in the best interests of the public stockholders of Genzyme;

iii.Acting independently so that the interests of the Company’s public stockholders will be protected; and

c.Directing Defendants to account to Plaintiff and the Class for their damages sustained because of the wrongs complained of herein;

d.Awarding Plaintiff the costs of this action, including reasonable attorneys’, accountants’, and experts’ fees; and

10

e.Granting such other and further relief as this Court may deem just and proper.

Dated: September 8, 2010	By his attorney,
	/s/ Kenneth G. Gilman
	Kenneth G. Gilman, BBO# 192760
	16 Fourteenth Avenue
	Wareham, MA 02571
	Telephone: (508) 291-8400
	Facsimile: (508) 291-3258
	kgilman@gilmanpastor.com
	WOLF HALDENSTEIN ADLERFREEMAN HERZ LLP
	Gregory M. Nespole
	Gustavo Bruckner
	Martin E. Restituyo
	270 Madison Avenue
	New York, New York 10016
	Phone: (212) 545-4600
	Fax: (212) 545-4653
	Counsel for Plaintiff

11

EX-99.(A)(7)

Exhibit (a)(7)

UNITED STATES DISTRICT COURT

DISTRICT OF MASSACHUSETTS

EMANUEL RESENDES, On Behalf Of himself		)	No.
and All Others Similarly Situated,		)
		)
	Plaintiff,	)
		)	CLASS ACTION
vs.		)
		)
HENRI A. TERMEER, MICHAEL S.		)	CLASS ACTION COMPLAINT BASED
WYZGA, ROBERT J. CARPENTER,		)	UPON SELF-DEALING AND BREACH
CHARLES L. COONEY, DOUGLAS A.		)	OF FIDUCIARY DUTY
BERTHIAUME, GAIL K. BOUDREAUX,		)
ROBERT J. BERTOLINI, VICTOR J. DZAU,		)	JURY TRIAL DEMANDED
CONNIE MACK III, RICHARD F. SYRON,		)
RALPH V. WHITWORTH, STEVEN		)
BURAKOFF, ERIC ENDE, AND DENNIS M.		)
FENTON,		)
		)
	Defendants	)
		)

SUMMARY OF THE ACTION

1.This is a stockholder class action brought by plaintiff on behalf of the holders of Genzyme Corporation (“Genzyme” or the “Company”) common stock. This action is brought against the members of the Company’s Board of Directors (“Board”) arising out of defendants’ illegal breach of fiduciary duties in attempting to entrench themselves in office and their failure to properly consider indications of interest to acquire the company from suitors such as Sanofi-Aventis (“Sanofi”) at a significant premium.

2.For several months, Sanofi has been seeking a meeting with Genzyme to discuss a merger or other business combination.  On July 29, 2010, Sanofi made an offer to acquire Genzyme in an all-cash transaction valued at approximately $18.5 billion. Under the terms of the proposed acquisition, Genzyme shareholders would receive $69 per share in cash, representing a 38% premium over Genzyme’s unaffected share price of $49.86 on July 1, 2010. Sanofi’s offer also represents a premium of almost 31% over the one-month historical average share price through July 22, 2010, the day prior to press speculation that Sanofi had made an approach to acquire Genzyme. Based on analyst consensus estimates, the offer represents a multiple of 36 times Genzyme’s 2010 earnings per share and 20 times 2011 earnings per share. Accordingly, the offer price takes into account the upside potential of the anticipated recovery in Genzyme’s performance in 2011.

3.Despite the fact that Genzyme’s stock price has significantly underperformed that of its peers over the last several years, and the fact that a takeover bid from Sanofi would offer a significant premium to Genzyme shareholders, the Board swiftly rejected the offer, without giving due consideration or deliberation to the offer, and has refused to even meet with Sanofi. Even worse, the Board has entrenched itself and discouraged any public bid for Genzyme.

4.The Board went so far as conveying to the market that Genzyme was not for sale. As one analyst and significant Genzyme shareholder stated: “We aren’t crazy about comments that the company isn’t for sale and, based on Sanofi’s comments, they [Genzyme’s Board] said it wasn’t for sale even before they knew the number.” David Katz, the chief investment officer of Matrix Assets Advisors, which owns 320,000 Genzyme shares.

5.On September 5, 2010, Dow Jones reported that Sanofi is willing to increase its offer if the Individual Defendants named herein (i.e., the Genzyme board) negotiates in good faith and enters into a negotiated deal.

6.In pursuing their unlawful plan to entrench themselves in their lucrative positions as directors of a large, publicly traded Company, and refusing to act in good faith and in accordance with the fiduciary duties owed to Genzyme and its shareholders, the Company’s Board violated applicable law by directly breaching and/or aiding the other defendants’ breaches of their fiduciary duties of loyalty, due care, independence, good faith and fair dealing. Rather than acting in the best interests of the Company and its shareholders, as their fiduciary duties mandate, defendants — without good faith consideration — are attempting to frustrate Sanofi’s bid and further entrench themselves as officers and managers of the Company.  Defendants have breached their fiduciary duties by failing to consider in good faith the Sanofi offer and otherwise failing to take actions to maximize shareholder value. Instead, defendants are acting in their own self-interest.

JURISDICTION AND VENUE

7.This Court has jurisdiction over all causes of action asserted herein pursuant to the Class Action Fairness Act of 2005, 28 U.S.C. § 1332(d)(2) because (i) the amount in controversy exceeds the jurisdictional amount of $5,000,000; (ii) the Class consist of hundreds, and perhaps thousands, of individuals; and (iii) minimal diversity exists between Plaintiff and Defendants.

8.This Court has jurisdiction over each defendant named herein because each defendant is either a corporation that conducts business in and maintains operations in this District, or is an individual who has sufficient minimum contacts with this District so as to render the exercise of jurisdiction by the District courts permissible under traditional notions of fair play and substantial justice.

9.Venue is proper in this Court pursuant to 28 U.S.C. §1391(a) because: (i) Genzyme maintains its principal place of business in this District; (ii) one or more of defendants either resides in or maintains executive offices in this District; (iii) a substantial

portion of the transactions and wrongs complained of herein, including defendants’ primary participation in the wrongful acts detailed herein, and aiding and abetting and conspiracy in violation of fiduciary duties owed to Genzyme, occurred in this District; and (iv) defendants have received substantial compensation in this District by doing business here and engaging in numerous activities that had an effect in this District.

PARTIES

10.Plaintiff Emanuel Resendes holds common stock of Genzyme and acquired his Genzyme stock prior to the time of the alleged wrongdoing alleged herein. Plaintiff is a citizen of the Commonwealth of Massachusetts.

11.Defendant Termeer is Genzyme’s Chief Executive Officer and has been since December 1985; Chairman of the Board and has been since May 1988; and President and a director and has been since October 1983. Defendant Termeer is a citizen of Massachusetts.

12.Defendant Michael S. Wyzga (“Wyzga”) is Genzyme’s Executive Vice President, Finance and has been since May 2003 and Chief Financial Officer and has been since July 1999. Wyzga was also Genzyme’s Chief Accounting Officer from January 1999 to November 2008; Senior Vice President, Finance from July 1999 to May 2003; Senior Vice President, Corporate Controller from January 1999 to July 1999; and Vice President and Corporate Controller from February 1998 to January 1999. Defendant Wyzga is a citizen of Massachusetts.

13.Defendant Robert J. Carpenter (“Carpenter”) is a Genzyme director and has been since 1994. Defendant Carpenter is a citizen of Massachusetts.

14.Defendant Charles L. Cooney (“Cooney”) is Genzyme director and has been since 1983. Defendant Cooney is a citizen of Massachusetts.

15.Defendant Douglas A. Berthiaume (“Berthiaume”) is a Genzyme director and has been since 1988. Defendant Berthiaume is a citizen of Massachusetts.

16.Defendant Gail K. Boudreaux (“Boudreaux”) is a Genzyme director and has been since 2004. Defendant Boudreaux is a citizen of Illinois.

17.Defendant Robert J. Bertolini (“Bertolini”) is a Genzyme director and has been since December 2009. Defendant Bertolini is a citizen of New Jersey.

18.Defendant Victor J. Dzau (“Dzau”) is a Genzyme director and has been since 2000. Defendant Dzau is a citizen of North Carolina.

19.Defendant Connie Mack III (“Mack”) is a Genzyme director and has been since 2001. Defendant Mack is a citizen of Florida.

20.Defendant Richard F. Syron (“Syron”) is a Genzyme director and has been since 2006. Defendant Syron is a citizen of Massachusetts.

21.Defendant Whitworth is a Genzyme director and has been since April 2010. Defendant Whitworth is a citizen of California.

22.Defendant Burakoff is a Genzyme director and has been since June 2010. Defendant Burakoff is citizen of New York.

23.Defendant Ende is a Genzyme director and has been since June 2010. Defendant Ende is a citizen of Florida.

24.Defendant Dennis M. Fenton (“Fenton”) is a Genzyme director and has been since June 2010. Defendant Fenton is a citizen of California.

25.By virtue of their positions as directors and/or officers of Genzyme and/or their exercise of control and ownership over the business and corporate affairs of Genzyme, defendants have, and at all relevant times had, the power to control and influence and did control and influence and cause Genzyme to engage in the practices complained of herein.  Each Individual Defendant owed and owes Genzyme and its shareholders fiduciary obligations and were and are required to: (1) use their ability to control and manage Genzyme in a fair, just and equitable manner; (2) act in furtherance of the best interests of Genzyme and its shareholders; (3) act to maximize shareholder value in connection with any change in ownership and control to the extent consistent with governing statutes; (4) govern Genzyme in such a manner as to heed the expressed views of its public shareholders; (5) refrain from abusing their positions of control; and (6) not favor their own interests at the expense of Genzyme and its public shareholders.

26.Each defendant herein is sued individually and as an aider and abettor and in his capacity as a director of Genzyme. The liability of each of defendants arises from the fact that

they have engaged in all or part of the unlawful acts, plans, schemes, or transactions complained of herein.

FIDUCIARY DUTIES OF THE DEFENDANTS

27.By reason of defendants’ positions with the Company as officers and/or directors, said individuals are in a fiduciary relationship with plaintiff and the other public stockholders of Genzyme and owe the Company, as well as plaintiff and the other members of the Class, duties of the highest good faith, fair dealing, loyalty and full, candid and adequate disclosure.

28.The claims are brought under Massachusetts state law which requires every corporate director to act in good faith, in the best interests of the corporation and its shareholders, and to act with such care, including reasonable inquiry, as would be expected of an ordinarily prudent person. In a situation where a bona fide offer is presented to a company that represents a substantial premium over the trading price of its stock, applicable state law requires the directors to take all steps reasonably required to properly evaluate and respond in good faith to the offer. To diligently comply with this duty, the directors of a corporation may not take any action that:

(a)adversely affects the value provided to the corporation’s shareholders;

(b)contractually prohibits them from complying with or carrying out their fiduciary duties;

(c)discourages or inhibits alternative offers to purchase the corporation or its assets; or

(d)will otherwise adversely affect their duty to search and secure the best value reasonably available under the circumstances for the corporation’s shareholders.

29.In accordance with their duties of loyalty and good faith, defendants, as directors and/or officers of Genzyme, are obligated to refrain from:

(a)participating in any transaction where the directors’ or officers’ loyalties are divided;

(b)participating in any transaction where the directors or officers receive or are entitled to receive a personal financial benefit not equally shared by the public shareholders of the corporation;

(c)unjustly enriching themselves at the expense or to the detriment of the public shareholders, and/or

(d)unjustly entrenching themselves as managers and/or officers of the Company by failing to give adequate consideration to legitimate bids for the Company.

30.The defendants, separately and together, have violated the fiduciary duties owed to Genzyme and its public shareholders, including their duties of loyalty, good faith and independence, insofar as they have failed to give proper and good faith consideration to the Sanofi bid, which represents a significant premium over the stock’s trading price in the days, weeks, and months prior to the offer, for the purpose of entrenching themselves in the lucrative positions as managers of a large publicly traded corporation and to obtain for themselves personal benefits.

31.Because defendants have breached their duties of loyalty, good faith and independence in connection with their failure to act in good faith to consider the Sanofi bid, defendants, as a matter of Massachusetts law, have breached their fiduciary duties of good faith and fair dealing owed to the shareholders of the Company and to the Company itself.

THE OFFER DEFENDANTS IGNORED

32.On July 23, 2010, The New York Times published an article titled “Sanofi Said to Have Offered to Make a Bid for Genzyme.” The article stated:

Sanofi-Aventis has made an informal takeover approach to Genzyme, a person briefed on the matter said on Friday, as the French drug maker seeks to bolster its biotechnology offerings.

* * *

Genzyme would bring Sanofi an attractive portfolio of drugs that treat rare conditions like Fabry disease. Because of their relative complexity, Genzyme’s products fetch high prices. Cerezyme, a treatment for Gaucher’s disease and one

of the company’s main products, has garnered more than $1 billion in annual sales, though it is used to treat fewer than 6,000 patients.

33.Under the terms of the proposed acquisition, Genzyme shareholders would receive $69 per share in cash, representing a 38% premium over Genzyme’s unaffected share price of $49.86 on July 1, 2010. Sanofi’s offer also represents a premium of almost 31% over the one-month historical average share price through July 22, 2010, the day prior to press speculation that Sanofi had made an approach to acquire Genzyme. Based on analyst consensus estimates, the offer represents a multiple of 36 times Genzyme’s 2010 earnings per share and 20 times 2011 earnings per share. Accordingly, the offer price takes into account the upside potential of the anticipated recovery in Genzyme’s performance in 2011.

34.In addition, the offer of $69 was merely an opening offer to start negotiations. The chief executive of Sanofi, Chris Viehbacher, affirmed that he thought that $69 a share was a realistic starting point as he left the door open to negotiating a higher offer. Indeed, in view of the Company’s positive future, the Board was well positioned to negotiate a higher price.

35.In a July 26, 2010 article on Bloomberg.com, Sven Borho, an analyst with OrbiMed Advisors stated that “if two or three companies get involved in bidding, the $80s are achieved really easily… There are so few good assets out there, and this is one of the more promising assets.” In addition to Sanofi, the Bloomberg.com article stated that GlaxoSmithKline Plc recently made an overture to Genzyme.  And other reports have claimed that Johnson & Johnson is also interested in pursuing an acquisition of Genzyme.

36.On July 28, 2010, The New York Times DealBook stated that people briefed on the matter indicated Sanofi-Aventis was willing to pay at least $70 per share.  According to a Bloomberg Businessweek article, Sanofi’s Board has actually authorized an offer of $70 per share.  While an offer at that price represents a premium, the Company stock price recently traded at more than $83 prior to the manufacturing problems caused by defendants, and as

recently as January 2010, Relational stated that it believes Genzyme could achieve a stock price as high as $90.

37.On September 5, 2010, Dow Jones reported that the Sanofi-Aventis board was willing to pay more than the current offer if the Genzyme board would stop entrenching itself in office and instead negotiate in good faith.

38.Despite its leverage to negotiate a higher price for the benefit of the shareholders, the Board has refused to even meet with Sanofi. Even Sanofi’s chief executive expressed his surprise in a letter he personally sent to Defendant Termeer (Genzyme’s Chairman, President and Chief Executive Officer):

We are disappointed that you rejected our proposal on August 11 without discussing its substance with us.

…

Your continued refusal to enter into constructive discussions will serve only to further delay the ability of your shareholders to receive the substantial value represented by our all-cash offer. We therefore are prepared to consider all alternatives to complete this transaction.

39.Despite these offers to negotiate a fair price for Genzyme’s shareholders, defendants chose to entrench themselves in their lucrative positions as directors of a large, publicly-traded Company, and refused to act in good faith and in accordance with the fiduciary duties owed to Genzyme and its shareholders.

40.Dow Jones Newswires reported that at least one Genzyme shareholder is unhappy with what it sees as Genzyme’s resistance to negotiating a deal. “We aren’t crazy about comments that the company isn’t for sale and, based on Sanofi’s comments, they [Genzyme’s Board] said it wasn’t for sale even before they knew the number,” David Katz, the chief investment officer of Matrix Assets Advisors, which owns 320,000 Genzyme shares, told Dow Jones.

41.While the Individual Defendants have publicly stated their opinion that the current Sanofi offer fails to attribute sufficient value to Campath, a multiple sclerosis drug that is in the experimental stages, there is a very easy (and commonly utilized) structure through which Genzyme can ensure that its shareholders participate in the future benefits of Campath: building into the deal an earn-out arrangement in which shareholders would be paid additional dividends based on the future success of Campath.

42.To comply with their fiduciary duties, the Genzyme board should negotiate in good faith with Sanofi-Aventis, including attempting to negotiate a higher premium offer, including the potential of an earn-out arrangement addressing Campath and any other promising drugs in Genzyme’s pipeline. The Genzyme board should also shop the Company to other suitors so as to obtain maximum value for the Class in any sales process.

CLASS ACTION ALLEGATIONS

43.Plaintiff brings this action individually and as a class action pursuant to Federal Rule of Civil Procedure 23 on behalf of all holders of Genzyme stock who are being and will be harmed by defendants’ actions described herein (the “Class”). Excluded from the Class are defendants herein and any person, firm, trust, corporation, or other entity related to or affiliated with any defendant.

44.This action is properly maintainable as a class action.

45.The Class is so numerous that joinder of all members is impracticable. According to Genzyme’s United States Securities and Exchange Commission filings, there are more than 254.8 million shares of Genzyme common stock outstanding.

46.There are questions of law and fact which are common to the Class and which predominate over questions affecting any individual Class member.  The common questions include, inter alia, the following:

(a)whether defendants have breached their fiduciary duties of undivided loyalty, independence or due care with respect to plaintiff and the other members of the Class as a result of taking action to frustrate a bid from Sanofi and seek a superior offer;

(b)whether defendants are attempting to entrench themselves as managers and officers of the Company in order to preserve their lucrative and prestigious positions at the expense of maximizing shareholder value by failing to give adequate consideration to offers and overtures to acquire the Company at substantial premiums;

(c)whether defendants have breached their fiduciary duty by adopting lucrative change of control agreements;

(d)whether defendants are attempting to unjustly enrich themselves and other insiders or affiliates of Genzyme as a result of their efforts to entrench themselves as managers and directors of the Company;

(e)whether defendants have breached any of their other fiduciary duties to plaintiff and the other members of the Class in connection with taking action to frustrate a bid by Sanofi and/or other suitors and failure to comply with the duties of good faith, diligence, candor and fair dealing; and

(f)whether defendants, in bad faith and for improper motives, have impeded or erected barriers to discourage this or any other offers for the Company or its assets.

47.Plaintiff’s claims are typical of the claims of the other members of the Class and plaintiff does not have any interests adverse to the Class.

48.Plaintiff is an adequate representative of the Class, has retained competent counsel experienced in litigation of this nature and will fairly and adequately protect the interests of the Class.

49.The prosecution of separate actions by individual members of the Class would create a risk of inconsistent or varying adjudications with respect to individual members of the Class which would establish incompatible standards of conduct for the party opposing the Class.

50.Plaintiff anticipates that there will be no difficulty in the management of this litigation.  A class action is superior to other available methods for the fair and efficient adjudication of this controversy.

51.Defendants have acted and are acting on grounds generally applicable to the Class with respect to the matters complained of herein, thereby making appropriate the relief sought herein with respect to the Class as a whole.

FIRST CAUSE OF ACTION

Claim for Breach of Fiduciary Duties Against the Defendants

52.Plaintiff incorporates by reference and realleges each and every allegation contained above, as though fully set forth herein.

53.Defendants have violated fiduciary duties of care, loyalty, candor, good faith and independence owed to the public shareholders of Genzyme and have acted to put their personal interests ahead of the interests of Genzyme shareholders.

54.By the acts, transactions and courses of conduct alleged herein, defendants, individually and acting as a part of a common plan, have violated their fiduciary duties by disenfranchising Genzyme’s public shareholders, and by failing to give adequate consideration to a potential sale of the Company at a substantial premium to the public shareholders of the Company.

55.As demonstrated by the allegations above, defendants failed to exercise the care required, and breached their duties of loyalty, good faith, candor and independence owed to the shareholders of Genzyme because, among other reasons:

(a)they have failed to properly and adequately consider expressions of interest to acquire the Company or take other necessary steps to maximize the value of Genzyme to its public shareholders;

(b)they failed to properly maximize the value of Genzyme common stock; and

(c)they ignored or did not protect against the numerous conflicts of interest resulting from the directors’ own interrelationships in connection with their refusal to consider bona fide and legitimate expressions of interest to acquire the Company at a premium.

56.Because defendants dominate and control the business and corporate affairs of Genzyme, and are in possession of private corporate information concerning Genzyme’s assets

(including the knowledge of any other undisclosed bids for the Company), business and future prospects, there exists an imbalance and disparity of knowledge and economic power between them and the public shareholders of Genzyme which makes it inherently unfair for them to reject any proposed transaction for the sole purpose of entrenching themselves as managers and directors of the Company, to the exclusion of maximizing stockholder value.

57.By reason of the foregoing acts, practices and course of conduct, defendants have failed to exercise ordinary care and diligence in the exercise of their fiduciary obligations toward plaintiff and the other members of the Class.

58.As a result of defendants’ acts, practices and course of conduct, plaintiff and the Class have been and will be harmed.

59.Defendants are engaging in self dealing, are not acting in good faith toward plaintiff and the other members of the Class, and have breached and are breaching their fiduciary duties to the members of the Class.

PRAYER FOR RELIEF

WHEREFORE, plaintiff demands judgment and preliminary and permanent relief, in his favor and in favor of the Class and against defendants as follows:

A.Declaring that, as to the First Cause of Action, this action is properly maintainable as a class action;

B.Declaring and decreeing that defendants’ conduct has been in breach of the fiduciary duties owed by defendants to its public stockholders;

C.Declaring and decreeing that defendants’ refusal to consider and respond in good faith to any offers to acquire Genzyme is in breach of the fiduciary duties owed by defendants to its shareholders and ordering defendants to comply with said fiduciary duties;

D.Directing defendants to refrain from advancing their own interests at the expense of the class and exercise their fiduciary duties to act reasonably and respond in good faith to offers which are in the best interest of the class;

E.Prohibiting defendants from entering into any contractual provisions which harm the class or prohibit defendants from maximizing shareholder value, including any confidentiality agreement or contract designed to impede the maximization of shareholder value;

F.Prohibiting defendants from adopting, implementing or instituting any defensive measures that has or is intended to have the effect of making the consummation of an offer to purchase the Company more difficult or costly for a potential acquiror;

G.Awarding plaintiff the costs and disbursements of this action, including reasonable attorneys’ and experts’ fees; and

H.Granting such other and further relief as this Court may deem just and proper.

JURY TRIAL DEMAND

Plaintiff demands a trial by jury of all issues so triable.

Dated: September 9, 2010
	HUTCHINGS, BARSAMIAN,
	MANDELCORN & ZEYTOONIAN, LLP
	/s/Theodore M. Hess-Mahan
	Theodore M. Hess-Mahan, BBO #557109
	110 Cedar Street, Suite 250
	Wellesley Hills, MA 02481
	Phone: (781) 431-2231
	Facsimile: (781) 431-8726
	JOHNSON BOTTINI, LLP
	FRANK J. JOHNSON
	FRANCIS A. BOTTINI, JR.
	SHAWN FIELDS
	501 West Broadway, Suite 1720
	San Diego, CA 92101
	(619) 230-0063 (telephone)
	(619) 238-0622 (facsimile)
	Attorneys for Plaintiff

EX-99.(A)(8)

Exhibit (a)(8)

UNITED STATES DISTRICT COURT

DISTRICT OF MASSACHUSETTS

WILLIAM S. FIELD, III, TRUSTEE U/A	Civil Action No.
DATED OCTOBER 12, 1991 BY
WILLIAM S. FIELD JR, individually, and
on behalf of all others similarly situated,
	SHAREHOLDER CLASS ACTION COMPLAINT
Plaintiff,
vs.
HENRI A. TERMEER, MICHAEL S.
WYZGA, ROBERT J. CARPENTER,
CHARLES L. COONEY, DOUGLAS A.	JURY TRIAL DEMANDED
BERTHIAUME, GAIL K. BOUDREAUX,
ROBERT J. BERTOLINI, VICTOR J.
DZAU, CONNIE MACK III, RICHARD F.
SYRON, RALPH V. WHITWORTH,
STEVEN BURAKOFF, ERIC ENDE,
DENNIS M. FENTON, GENZYME CORP.,
Defendants.

Plaintiff, William S. Field, III, Trustee u/a dated October 12, 1991, by William S. Field Jr. (“Plaintiff”), individually and on behalf of all other persons similarly situated, alleges the following based upon the investigation by Plaintiff’s counsel, which included, inter alia, a review of the Securities and Exchange Commission (“SEC”) filings, wire and press releases, securities analysts’ reports, advisories, news articles and information readily obtainable on the Internet.

NATURE OF THE ACTION

1.Plaintiff brings this action individually and as a class action on behalf of all persons, other than Defendants and their affiliates, who own Genzyme Corporation (“Genzyme” or the “Company”) common stock, against Genzyme and certain of its officers and directors, and are similarly situated (the “Class”), for compensatory damages and equitable relief because the

1

individual defendants have put their own self-interests ahead of those of the public shareholders as evidenced by their response to the proposal to acquire the Company by Sanofi-Aventis (“Sanofi”), publicly announced on August 29, 2010 (the “Proposal” or the “Bid”).

2.Genzyme is a Massachusetts corporation located in Cambridge, Massachusetts. The Company is a global biotechnology company that is focused on rare genetic disease disorders, renal disease, orthopedics, cancer, transplant and immune disease, and diagnostic and predictive testing. Genzyme is protected from generic competition because its products and pipeline focus on extremely rare genetic diseases.

3.While the Company has an enviable product pipeline and current valuable products, under the direction of Genzyme Chief Executive Officer (“CEO”), defendant Henri A. Termeer (“Termeer”), the Company has experienced continuous problems with its manufacturing facilities, which led to a series of regulatory actions taken by the federal Food and Drug Administration (“FDA”).

4.On February 27, 2009, the FDA sent the Company a warning letter over what federal regulators described as “significant objectionable conditions” at its Boston manufacturing plant. A few months later, the Company shut down its Boston plant after it was found to have a viral contamination. Unsurprisingly, the market reacted negatively to these significant, but curable, problems.

5.The Company’s manufacturing problems pushed the Company’s stock from a high of $83.06 on August 15, 2008, to its lowest point in over five years of $47.81 in June 2010. Moreover, a federal securities fraud class action was filed against the Company and multiple shareholders filed shareholder derivative actions against the Company’s directors and certain of its officers relating to the manufacturing problems and the FDA warning letters.

2

6.At least four of the directors are beholden to outside influences from activist investors. Defendants Steven Burakoff (“Burakoff”), Eric Ende (“Ende”), Dennis M. Fenton (“Fenton”), and Ralph V. Whitworth (“Whitworth”) are all Board of Directors (“Board”) members that are conflicted because they were forced onto the Board by Relational Investors LLC (“Relational”) and Carl C. Icahn to pursue their own interests. These activist investors are concerned with their short term profits rather than maximizing shareholder value.

7.While activist investors pursue their own goals, the rights and interests of the Company’s public shareholders are not being adequately represented because the Individual Defendants have breached their fiduciary duties of loyalty, due care, independence, good faith, and fair dealing.

8.At the expense of the public shareholders, Defendants refused out rightly to pursue the $18.5 billion bid for the Company by Sanofi which will cost the public shareholders of Genzyme the opportunity to entertain a substantial premium offer for their shares.

9.The rejection by Defendants of the Bid is improper and unlawful. To remedy and prevent further breaches of fiduciary duties and other misconduct, Plaintiff seeks, inter alia, an order from the court appointing an independent special committee of the Company with full authority to (1) evaluate, negotiate and if in the best interests of all of the shareholders equally accept the Bid or, if possible, a higher bid; and (2) pursue other opportunities to obtain the highest value reasonably available for the shareholders in the Company.

10.Plaintiff also seeks compensatory damages on behalf of himself as Trustee and on behalf of the class for the diminution of the value of their stock in the Company resulting from the conduct of the Individual Defendants, together with interest and costs including reasonable attorneys’ fees.

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PARTIES

11.Plaintiff, a resident of the Commonwealth of Virginia, at all relevant times, has been a continuous owner of common stock shares of Genzyme.

12.Defendant Termeer is Genzyme’s Chief Executive Officer and has been since December 1985; Chairman of the Board and has been since May 1988; and President and a director and has been since October 1983. Defendant Termeer is a citizen of Massachusetts.

13.Defendant Michael S. Wyzga (“Wyzga”) is Genzyme’s Executive Vice President, Finance and has been since May 2003 and Chief Financial Officer and has been since July 1999. Wyzga was also Genzyme’s Chief Accounting Officer from January 1999 to November 2008; Senior Vice President, Finance from July 1999 to May 2003; Senior Vice President, Corporate Controller from January 1999 to July 1999; and Vice President and Corporate Controller from February 1998 to January 1999. Defendant Wyzga is a citizen of Massachusetts.

14.Defendant Robert J. Carpenter (“Carpenter”) is a Genzyme director and has been since 1994. Defendant Carpenter is a citizen of Massachusetts.

15.Defendant Charles L. Cooney (“Cooney”) is a Genzyme director and has been since 1983. Defendant Cooney is a citizen of Massachusetts.

16.Defendant Douglas A. Berthiaume (“Berthiaume”) is a Genzyme director and has been since 1988. Defendant Berthiaume is a citizen of Massachusetts.

17.Defendant Gail K. Boudreaux (“Boudreaux”) is a Genzyme director and has been since 2004. Defendant Boudreaux is a citizen of Illinois.

18.Defendant Robert J. Bertolini (“Bertolini”) is a Genzyme director and has been since December 2009. Defendant Bertolini is a citizen of New Jersey.

19.Defendant Victor J. Dzau (“Dzau”) is a Genzyme director and has been since 2000. Defendant Dzau is a citizen of North Carolina.

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20.Defendant Connie Mack III (“Mack”) is a Genzyme director and has been since 2001. Defendant Mack is a citizen of Florida.

21.Defendant Richard F. Syron (“Syron”) is a Genzyme director and has been since 2006, Defendant Syron is a citizen of Massachusetts.

22.Defendant Whitworth is a Genzyme director and has been since April 2010. Defendant Whitworth is a citizen of California.

23.Defendant Burakoff is a Genzyme director and has been since June 2010. Defendant Burakoff is citizen of New York.

24.Defendant Ende is a Genzyme director and has been since June 2010. Defendant Ende is a citizen of Florida.

25.Defendant Dennis M. Fenton (“Fenton”) is a Genzyme director and has been since June 2010. Defendant Fenton is a citizen of California.

26.The defendants named in paragraphs 13 through 26 above are hereinafter referred to as the “Individual Defendants.”

27.Defendant Genzyme Corp. (“Genzyme”) is a Massachusetts biotechnology company with a broad product and service portfolio focused on rare genetic disease disorders, renal disease, orthopedics, cancer, transplant and immune disease, and diagnostic and predictive testing. Defendant Genzyme is a citizen of Massachusetts with a principal place of business in Cambridge, Massachusetts.

28.The Individual Defendants, by reason of their corporate directorship and/or executive positions, are fiduciaries to and for the Company’s shareholders, and as such are required to: (a) exercise their best judgment; (b) use their ability to control and manage Genzyme in a fair, just and equitable manner; (c) to act prudently and in the best interests of the

5

Company’s shareholders; and (d) avoid all conflicts of interest or abstain from voting.

JURISDICTION AND VENUE

29.This Court has jurisdiction over all causes of action asserted herein pursuant to 28 U.S.C. § 1332(a)(2) in that plaintiff and defendants are citizens of different states and the amount in controversy exceeds $75,000, exclusive of interest and costs. This action is not a collusive action designed to confer jurisdiction on a court of the United States that it would not otherwise have.

30.This Court has jurisdiction over each defendant named herein because each defendant is either a corporation that conducts business in and maintains operations in this District, or is an individual who has sufficient minimum contacts with this District so as to render the exercise of jurisdiction by the District courts permissible under traditional notions of fair play and substantial justice.

31.Venue is proper in this Court pursuant to 28 U.S.C. §1391(a) because: (a) Genzyme maintains its principal place of business in this District; (b) one or more of the defendants either resides in or maintains executive offices in this District; (c) a substantial portion of the transactions and wrongs complained of herein, including the Defendants’ primary participation in the wrongful acts detailed herein, and aiding and abetting and conspiracy in violation of fiduciary duties owed to Genzyme, occurred in this District; and (d) the Defendants have received substantial compensation in this District by doing business here and engaging in numerous activities that had an effect in this District.

CLASS ACTION ALLEGATIONS

32.Plaintiff brings this action individually, and as a class action, on behalf of all stockholders of the Company (except the Defendants herein and any person, firm, trust,

6

corporation, or other entity related to or affiliated with any of the Defendants) and their successors in interest, who are or will be threatened with injury arising from Defendants’ actions as is described more fully below.

33.The claims asserted herein are properly maintainable as class action counts because:

(a)The Class is so numerous that joinder of all members is impractical. As of June 30, 2010, the Company had outstanding 254.84 million shares of its common stock, held by individuals and entities too numerous to bring separate actions. It is reasonable to assume that holders of the common stock are geographically dispersed throughout the United States;

(b)There are questions of law and fact which are common to the Class, and which predominate over questions affecting any individual Class member(s). The common questions include, inter alia, the following:

(c)Whether the Defendants have breached their fiduciary duties owed by them to Plaintiff and the other members of the Class;

(d)Whether the Defendants are unlawfully entrenching themselves in a controlling position and preventing the Company’s shareholders from maximizing the value of their holdings; and

(e)Whether the Class is entitled to compensatory damages and/or equitable relief as a result of the wrongful conduct committed by the Defendants.

34.Plaintiff is a member of the Class and is committed to prosecuting this action. Plaintiff has retained competent counsel experienced in litigation of this nature. Plaintiffs claims are typical of the claims of the other members of the Class and Plaintiff has the same

7

interests as the other members of the Class. Accordingly, Plaintiff is an adequate representative of the Class and will fairly and adequately protect the interests of the Class.

35.Defendants have acted or refused to act on grounds generally applicable to the Class, thereby making appropriate the relief sought herein with respect to the Class as a whole.

36.The likelihood of individual Class members prosecuting separate individual actions is remote due to the relatively small loss suffered by each Class member as compared to the burden and expense of prosecuting litigation of this nature and magnitude. Absent a class action, the Defendants are likely to avoid liability for their wrongdoing, and Class members are unlikely to obtain redress for their wrongs alleged herein. There are no difficulties likely to be encountered in the management of the Class claims. This Court is an appropriate forum for this dispute.

THE INDIVIDUAL DEFENDANTS’ FIDUCIARY DUTIES

37.Under Massachusetts law, in any situation where the directors of a publicly traded corporation undertake a transaction that will result in either: (a) a change in corporate control; or (b) a breakup of the corporation’s assets, the directors have an affirmative fiduciary obligation to obtain the highest value reasonably available for the corporation’s shareholders, including a significant premium at the highest price attainable in the market.

38.To diligently comply with these duties, neither the directors nor the officers may take any action that:

(a)would adversely affect the value provided to the corporation’s shareholders;

(b)would discourage, inhibit or deter alternative offers to purchase control of the corporation or its assets;

(c)would contractually or de facto prohibit themselves from complying with their

8

fiduciary duties;

(d)would otherwise adversely affect their duty to secure the highest value reasonably available under the circumstances for the corporation’s shareholders; and/or

(e)Would provide the directors and/or officers with preferential treatment at the expense of, or separate from, the public shareholders.

39.In accordance with their duty of loyalty, the Individual Defendants, as directors and/or officers of Genzyme, are obligated under Massachusetts law to refrain from:

(a)participating in any transaction where the directors’ or officers’ loyalties are divided;

(b)participating in any transaction where the directors or officers receive, or are entitled to receive, a personal financial benefit not equally shared by the public shareholders of the corporation; and/or

(c)enriching themselves unjustly at the expense of or detriment to the public shareholders.

40.The Individual Defendants, separately and together, in connection with the Proposal, are negligently, recklessly or knowingly violating their fiduciary duties and aiding and abetting such breaches, including their duties of loyalty, good faith and independence owed to Plaintiff and other public shareholders of Genzyme,

41.Because the Individual Defendants are negligently, recklessly or knowingly breaching their duties of loyalty, good faith, and independence in connection with the Proposal, the burden of proving the inherent or entire fairness of the Proposal, including all aspects of its negotiation, structure, price, and terms, is placed upon the Defendants as a matter of law.

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THE PROPOSED ACQUISITION

42.On July 23, 2010, The New York Times published an article titled “Sanofi Said to Have Offered to Make a Bid for Genzyme.” The article stated:

Sanofi-Aventis has made an informal takeover approach to Genzyme, a person briefed on the matter said on Friday, as the French drug maker seeks to bolster its biotechnology offerings.

*   *   *

Genzyme would bring Sanofi an attractive portfolio of drugs that treat rare conditions like Fabry disease. Because of their relative complexity, Genzyme’s products fetch high prices. Cerezyme, a treatment for Gaucher’s disease and one of the company’s main products, has garnered more than $1 billion in annual sales, though it is used to treat fewer than 6,000 patients.

43.In a July 26, 2010 article on Bloomberg.com, Sven Borho, an analyst with OrbiMed Advisors stated that “if two or three companies get involved in bidding, the $80s are achieved really easily. There are so few good assets out there, and this is one of the more promising assets.” In addition to Sanofi, the Bloomberg.com article stated that GlaxoSmithKline Pic recently made an overture to Genzyme. And other reports have claimed that Johnson & Johnson is also interested in pursuing an acquisition of Genzyme.

44.Moreover, the premium being reported by reliable sources offers a minimal benefit at best. On July 28, 2010, The New York Times DealBook stated that people briefed on the matter indicated the acquisition would be at a price of $70 per share. Also, according to a Bloomberg BusinessWeek article, Sanofi’s Board has only authorized an offer of $70 per share. While the Proposal at that price is ostensibly at a premium, the Company stock price recently traded at more than $83 prior to the manufacturing problems caused by the Individual Defendants, and as recently as January 2010, Relational stated that it believes Genzyme could achieve a stock price as high as $90.

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45.On August 29, 2010, Sanofi made public its offer to buy Genzyme for $69 per share.

46.The following day, Monday, August 30,2010, Genzyme rejected the Proposal on the ground that it undervalued the company. In a letter to Sanofi, Genzyme’s chief executive, Defendant Termeer, said the board had unanimously rejected the offer. He said the board was “not prepared to engage” in negotiations with an “unrealistic” starting price.

47.The following day, it was reported that Matrix Asset Advisors, a Genzyme investor group, sent a letter to the Company’s board urging it to sit down at the table with Sanofi. The letter reads in part:

The Board must weigh the present values of Sanofi’s near-term, certain, cash proposal (or others that might emerge) against the longer and riskier stay-the-course approach. Based on Sanofi’s letter and conference call, it is clear that the $69/share bid is simply a starting point for negotiations, and that their appraisal can move meaningfully higher as Genzyme demonstrates why it should.

48.Matrix Chief Investment Officer David Katz said in an interview that if Genzyme begins negotiations at $69 per share, that consensus would likely be reached at a price in the mid $70s per share. If there is another bidder involved, Katz said, Genzyme would likely fetch a price in the low $80s per share. According to Katz, “There is a very substantial bid on the table. It is sufficient to start discussions, rather than waiting for a higher opening bid.”

49.In April, Matrix sent a letter to the Genzyme board urging the company to oust CEO Henri Termeer and to consider a sale of the company to a global pharmaceutical company.

50.On August 31, 2010, The Wall Street Journal reported that Genzyme may be taking a serious risk by not engaging in talks with Sanofi. In particular, it was reported that:

... taken too far, Genzyme’s strategy could backfire. By keeping Sanofi from doing due diligence, the U.S. firm risks limiting any bid price. Regulators forced Genzyme to slow production of key drugs, leaving the company at risk until

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inventories are restored, likely at the end of 2011. That worry is largely responsible for the decline in Genzyme shares from a high topping $83 in 2008 to around $54 just before Sanofi’s approach last month.

Without confidence the problems are resolved, even the current offer looks rich. Genzyme trades at 19.5 times next year’s consensus earnings, compared with a peer average around 10.3 times, says Jim Birchenough of Barclays Capital.

Sanofi looks likely to raise its bid above $70 to get conversations flowing. But it also has a strong negotiating position. If it walks, Genzyme’s shares would likely return to about $50, wiping out paper gains for activist investors. Merrill Lynch estimates Carl Icahn bought his Genzyme shares in the low-to-mid $50s, while Relational Investors acquired it’s in the low-to-mid $60s.

With no sign of other bidders, Genzyme should beware overplaying its hand.

51.As further evidence of the Defendants’ efforts to entrench themselves, on September 14, 2010, The Wall Street Journal reported that Genzyme agreed to sell its genetic-testing business to Laboratory Corp. of America Holdings for $925 million. The sale is part of the Defendants’ plan to also divest the Company of two additional divisions, including its diagnostics business, which sells tests and testing supplies, and its pharmaceuticals intermediates unit, which sells pharmaceutical materials and technologies to other drug companies. According to the Company, it plans to “use the total sale proceeds [from the three units] to finance the second half of a $2 billion stock buyback slated for completion by May 2011.”

THE UNFAIR AND INADEQUATE PROCESS

52.In order to meet their fiduciary duties, the Individual Defendants are obligated to explore transactions that will maximize shareholder value, and not structure a preferential deal for themselves. Due to their refusal to pursue in good faith the Sarnoff bid, the Individual Defendants have failed to obtain the highest value reasonably available for the benefit of Genzyme’s shareholders.

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53.As a result of Defendants’ conduct, Genzyme’s public stockholders have been and will continue to be denied a fair and adequate process for evaluating, negotiating and obtaining the highest value reasonably available to which the shareholders are legally entitled in a sale of their Company.

COUNT I

Breach of Fiduciary Duties of Loyalty, Due Care,
Good Faith and Fair Dealing against the Individual Defendants

54.Plaintiff incorporates by reference and re-alleges each and every allegation set forth above, as though fully set forth herein.

55.The Individual Defendants were and are under a duty to: (a) act in the interests of the equity owners; (b) maximize shareholder value; (c) undertake appropriate evaluation(s) of the proposed merger/acquisition offer(s); and (d) act in accordance with their fundamental duties of due care, loyalty, good faith and fair dealing; and refrain from acting where their interests conflict with those of the other Genzyme shareholders.

56.By the acts and courses of conduct alleged herein, the Individual Defendants, in breach of their fiduciary duties to Plaintiff and the other members of the Class, have failed to pursue the Bid or other bids in order to obtain highest value reasonably available to the Plaintiff and other members of the Class for their stock in Genzyme.

57.The Individual Defendants have refused to fairly and adequately evaluate or negotiate the premium offer from Sanofi for the Company’s common stock because they have put ahead of the Plaintiff’s and other shareholders’ interests their own self-interest in an attempt to entrench themselves for the purpose of maintaining control of the Company. The Defendants’ conduct is in direct violation of their fiduciary duties.

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58.As a result of the actions of the Individual Defendants, Plaintiff and the other members of the Class are and will be prevented from obtaining the highest value reasonably available for their shares of Genzyme common stock.

59.The conduct of the Individual Defendants as described above can only be prevented if this Court enters an order appointing an independent special committee of the Company with full authority to (a) evaluate, negotiate and if in the best interests of all of the shareholders equally accept the Sanofi bid or, if possible, a higher bid; and (b) pursue other opportunities to obtain the highest value reasonably available to the shares in the Company

60.Plaintiff and the Class are also entitled to compensatory damages together with interest and costs for diminution of the value of their shares as a result of the Individual Defendants’ conduct described above.

COUNT II

Breach of Fiduciary Duty of Disclosure against All Defendants

61.Plaintiff incorporates by reference and re-alleges each and every allegation set forth above, as though fully set forth herein.

62.The Defendants owe the duty of full and fair disclosure to the Company’s stockholders. The Individual Defendants have breached that duty as alleged above.

The Defendants’ breaches have and will damage Plaintiff and the Class. Due to this breach of duty, Plaintiff and the Class have no means by which to protect their interests absent the Court’s appointment of an independent special committee as described above.

PRAYER FOR RELIEF

WHEREFORE, Plaintiff prays for relief, in favor of the Class and against Defendants as follows:

1.A declaration that this action is properly maintainable as a class action;

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2.Entry of an order appointing an independent special committee of the Company with full authority to (a) evaluate, negotiate and if in the best interests of all of the shareholders equally accept the Sanofi bid or, if possible, a higher bid; and (b) pursue other opportunities to obtain the highest value reasonably available to the shares in the Company;

3.Entry of a judgment in favor of the Class against the Defendants for compensatory damages in an amount to be determined at trial, together with interest and costs , including reasonable attorneys’, accountants’, and experts’ fees; and

4.Such other and further relief as this Court may deem just and proper under the circumstances.

JURY TRIAL DEMANDED

Plaintiff hereby demands a trial by jury.

	PLAINTIFF WILLIAM S. FIELD, III, TRUSTEE U/A DATED OCTOBER 12,1991 BY WILLIAM S. FIELD JR, individually, and on behalf of all others similarly situated’
	By his attorneys,
	GELB & GELB LLP
BY:	/s/ Stamenia Tzouganatos
	Richard M. Gelb (BBO# 188240) rgelb@gelbgelb.com Daniel K. Gelb (BBO# 659703) dgelb@gelbgelb.com Stamenia (Stephanie) Tzouganatos (BBO# 661509) stzouganatos@ gelbgelb.com 84 State Street, 4th Fl. Boston, MA 02109 Tel: (617) 345-0010 Fax: (617) 345-0009

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	HARWOOD FEFFER LLP
	Robert I. Harwood Jeffrey M. Norton 488 Madison Ave. New York, NY 10022 Tel: (212) 935-7400 Fax: (212) 753-3630 rharwood@hfesq.com jnorton@hfesq.com
	LAW OFFICE OF ALFRED G. YATES JR., PC
	Alfred G.Yates, Jr. 519 Allegheny Building 429 Forbes Avenue Pittsburgh, PA 15219 Tel: (412) 391-5164
DATED:         September 14, 2010

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GENZYME CORP. VERIFICATION

I, William S. Field, III, hereby verify that I am familiar with the allegations set forth in the Complaint, that I have authorized the filing of the same, and that the foregoing is true and correct to the best of my knowledge, information, and belief.

DATED:	Aug. 31, 2010	/s/ William S. Field, III
		WILLIAM S. FIELD, III

EX-99.(A)(9)

Exhibit (a)(9)

COMMONWEALTH OF MASSACHUSETTS

MIDDLESEX, ss SUPERIOR COURT DEPARTMENT

CHESTER COUNTY EMPLOYEES
RETIREMENT FUND, on Behalf of Itself and
All Others Similarly Situated

Plaintiffs Case No. 10-3065

v.

GENZYME CORPORATION, HENRI A.
TERMEER, DOUGLAS A. BERTHIAUME,
ROBERT J. BERTOLINI, GAIL K.
BOUDREAUX, STEVEN J. BURAKOFF,
ROBERT J. CARPENTER, CHARLES L.
COONEY, VICTOR J. DZAU, ERIC J.
ENDE, DENNIS M. FENTON, CONNIE
MACK III, RICHARD F. SYRON and
RALPH V. WHITWORTH,

Defendants.

FILED

IN THE OFFICE OF THE

CLERK OF COURTS

FOR THE COUNTY OF MIDDLESEX

AUG 16 2010

/s/ [ILLEGIBLE]

CLERK

CLASS ACTION COMPLAINT

Chester County Employees Retirement Fund (“Plaintiff”), by and through its undersigned counsel, upon knowledge as to itself and upon information and belief as to all other matters, alleges as follows:

NATURE OF THE ACTION

1.Plaintiff is a holder of common stock of Genzyme Corporation (“Genzyme” or the “Company”). Plaintiff brings this action individually and as a class action on behalf of all holders of Genzyme’s common stock other than the defendants and their affiliates (the “Class”).

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Plaintiff seeks injunctive and other equitable relief to require Genzyme’s Board of Directors (the “Board”) to fulfill its fiduciary duties to the Company and its shareholders by pursuing good faith negotiations with Sanofi-Aventis SA (“Sanofi”), and any other potential bidders for the Company, and engaging in an open and honest process regarding the potential sale of the Company. Plaintiff also seeks to invalidate and to enjoin the Board’s deployment of any entrenchment and defensive measures designed to prevent Genzyme stockholders from receiving and accepting a valid and value-maximizing offer for their Genzyme shares.

THE PARTIES

2.Plaintiff is the owner of shares of common stock of Genzyme and has been the owner of such shares continuously since prior to the wrongs complained of herein.

3.Defendant Genzyme is a corporation duly existing and organized under the laws of Massachusetts, with its principal executive offices located at 500 Kendall Street, Cambridge, Massachusetts 02142. Genzyme is a biotechnology company with more than 12,000 employees in locations around the world. Genzyme is and at all times relevant hereto was listed and traded on the NASDAQ Stock Exchange under the symbol “GENZ.”

4.Defendant Henri A. Termeer (“Termeer”) has served as President of Genzyme since 1983, as Chief Executive Officer (“CEO”) of the Company since 1985, and as Chairman since 1988. Termeer is a member of the Risk Oversight Committee and the Strategic Planning and Capital Allocation Committee.

5.Defendant Douglas A. Berthiaume (“Berthiaume”) has served as a director of Genzyme since 1988. Berthiaume is a member of the Compensation Committee and the Nominating and Governance Committee.

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6.Defendant Robert J. Bertolini (“Bertolini”) has served as a director of Genzyme since 2009. Bertolini is chair of the Audit Committee and a member of the Strategic Planning and Capital Allocation Committee.

7.Defendant Gail K. Boudreaux (“Boudreaux”) has served as a director of Genzyme since 2004. Boudreaux is chair of the Risk Oversight Committee and a member of the Audit Committee.

8.Defendant Steven J. Burakoff (“Burakoff”) has served as a director of Genzyme since 2010. Burakoff is a member of the Compensation Committee and the Risk Oversight Committee. Burakoff was appointed to the Board as part of a proxy context settlement with Carl C. Icahn (“Icahn”), who purportedly holds approximately 4.9% of the Company’s outstanding stock.

9.Defendant Robert J. Carpenter (“Carpenter”) has served as a director of Genzyme since 1994. Carpenter currently serves as the Company’s Lead Independent Director.  Carpenter is a member of the Compensation Committee and the Strategic Planning and Capital Allocation Committee.

10.Defendant Charles L. Cooney (“Cooney”) has served as a director of Genzyme since 1983. Cooney is the chair of the Compensation Committee and a member of the Nominating and Governance Committee.

11.Defendant Victor J. Dzau (“Dzau”) has served as a director of Genzyme since 2000. Dzau is a member of the Compensation Committee and the Risk Oversight Committee.

12.Defendant Eric J. Ende (“Ende”) has served as a director of Genzyme since 2010. Ende is a member of the Audit Committee and the Risk Oversight Committee.   Ende was appointed to the Board as part of a proxy context settlement with Icahn.

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13.Defendant Ralph V. Whitworth (“Whitworth”) has served as a director of Genzyme since 2010.  Whitworth is chair of the Strategic Planning and Capital Allocation Committee and a member of the Compensation Committee and the Nominating and Governance Committee. Whitworth is a founder, principal, and investment committee member of Relational Investors LLC (“Relational”), an investment fund specializing in strategic block investments. According to the Company’s 2010 Proxy filed with the Securities and Exchange Commission (“SEC”), Whitworth owns 4% of the outstanding shares of Company common stock.

14.Defendant Connie Mack III (“Mack”) has served as a director of Genzyme since 2001. Mack is chair of the Nominating and Governance Committee and a member of the Audit Committee.

15.Defendant Richard F. Syron (“Syron”) has served as a director of Genzyme since 2006. Syron is a member of the Audit Committee and the Nominating and Governance Committee.

16.Defendant Dennis M. Fenton (“Fenton”) has served as a director of Genzyme since 2010. Fenton is a member of the Audit Committee and the Risk Oversight Committee. Fenton’s appointment to the Board on June 16, 2010 fulfilled a commitment made by the Company to nominate an independent director recommended by Relational.

17.The defendants referred to in paragraphs 4 through 16 are collectively referred to herein as the “Individual Defendants.”

CLASS ACTION ALLEGATIONS

18.Plaintiff brings this action individually and as a class action, pursuant to Rule 23 of the Massachusetts Rules of Civil Procedure, on behalf of all common stockholders of the

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Company (the “Class”). Excluded from the Class are defendants herein and any person, firm, trust, corporation or other entity related to or affiliated with any of the defendants.

19.This action is properly maintainable as a class action.

20.The Class is so numerous that joinder of all members is impracticable. As of April 9, 2010, there were over 266 million shares of Genzyme common stock outstanding.

21.There are questions of law and fact which are common to the Class including, inter alia, the following:

(a)whether defendants have breached their fiduciary and other common law duties owed by them to Plaintiff and the other members of the Class;

(b)whether Plaintiff and the other members of the Class will be irreparably harmed by the wrongs complained of herein; and

(c)whether Plaintiff and the Class are entitled to declaratory relief, injunctive relief or damages as a result of the wrongful conduct committed by defendants.

22.Plaintiff is committed to prosecuting this action and has retained competent counsel experienced in litigation of this nature. Plaintiff’s claims are typical of the claims of the other members of the Class and Plaintiff has the same interests as the other members of the Class. Accordingly, Plaintiff is an adequate representative of the Class and will fairly and adequately protect the interests of the Class.

23.The prosecution of separate actions by individual members of the Class would create the risk of inconsistent or varying adjudications with respect to individual members of the Class that would establish incompatible standards of conduct for defendants, or adjudications with respect to individual members of the Class that would as a practical matter be dispositive of

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the interests of the other members not party to the adjudications or substantially impair or impede their ability to protect their interests.

24.Defendants have acted, or refused to act, on grounds generally applicable to, and causing injury to, the Class and, therefore, preliminary and final injunctive relief on behalf of the Class, as a whole, is appropriate.

SUBSTANTIVE ALLEGATIONS

Genzyme Corporation

25.Founded in 1981, and initially operating out of the top floor of an office building in Boston’s Chinatown section, Genzyme has grown from a small start-up into one the world’s largest biotechnology companies with a product and service portfolio focused on rare genetic disease disorders, renal diseases, orthopedics, cancer, transplant and immune disease, and diagnostic and predictive testing. The Company operates in four business segments: Genetic Diseases, Cardiometabolic and Renal, Biosurgery and Hematologic Oncology.

26.Based on Fiscal Year 2009 (“FY09”) revenue, Genzyme’s top products include Cerezyme for the treatment of Gaucher disease ($793 million in FY09 revenue), Sevelamer for the treatment of renal, disease ($707 million in FY09 revenue), Fabrazyme for the treatment of Fabry disease ($431 million in FY09 revenue), and Synvisc for the treatment of osteoarthritis of the knee ($329 million in FY09 revenue).  In addition, the Company has several notable products in its pipeline, including alemtuzumb for the treatment of multiple sclerosis, mipomersen for the treatment of high-risk hypercholesterolemia, and eliglustat tartrate for the treatment of Gaucher disease. On July 22, 2010, the day before reports of Sanofi’s approach regarding a possible sale of the Company, Genzyme’s market value was $14.5 billion and its stock closed at $54.17 per share.

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27.Despite its headlining products and viable pipeline, the Company has been hindered by significant regulatory and manufacturing problems within the last year. In a commentary entitled “Bring Me the Head of Genzyme CEO Henri Termeer” published on CBS’ Interactive Business Network on November 17, 2009, Jim Edwards, a drug marketing analyst, summarized the woes of Genzyme as follows:

·“The FDA rejected Genzyme’s Lumizyme drug for Pompe Disease due to manufacturing “deficiencies” at its Allston Landing, Mass. plant.”

·“It was the second new drug application from Genzyme that the FDA has rejected. It nixed Clolar for leukemia in September.”

·“The Allston plant has been the subject of a five-week inspection.”

·“On Friday, garbage —steel, rubber and fiber — was found inside some of the drugs coming out the plant.”

·“Production at the plant was halted in June due to viral contamination.”

·“The company was warned in February that it wouldn’t pass an inspection unless it cleaned up its act.”

28.Echoing industry rumors, Edwards wondered at the time, “How long will it be before Genzyme CEO Henri Termeer resigns? That question was asked openly at TheStreet.com, which named Termeer the worst Biotech CEO of 2009.”

29.The most damaging and far reaching production problem encountered by the Company was the temporary closing of the Allston plant in June 2009 after it was contaminated by a virus that impairs cell growth. The closing directly impacted the production of Cerezyme and Fabrazyme, two key drugs from the Company’s genetic disease segment.

30.Genzyme has clearly struggled in the wake of its manufacturing problems, particularly its issues at the Allston plant. The Company’s sales slumped 2% to $4.5 billion in 2009 following the virus contamination, and the Company’s troubles have persisted. According

7

to recent public filings, during the second quarter of 2010, the Company’s net profit fell to $23,000, or nil per share, from $187.6 million, or $0.68 per share, a year before.  In addition, revenue fell to $1.08 billion from $1.23 billion a year ago, compared with analysts’ consensus forecasts of $1.16 billion.

31.As the Company acknowledges in its 2009 Annual Report, “we are now in a recovery period.” Citing setbacks in manufacturing operations that hindered the Company’s ability to fully supply Cerezyme and Fabrazyme, the Company admittedly, “did not meet [its] commitment to patients or to shareholders.” Indeed, in a May 24, 2010 press release, the Company acknowledged that it is “currently shipping Cerezyme at approximately 50 percent of demand and approximately 30 percent of demand for Fabrazyme.”

32.In addition to the impact on the Company’s performance, Genzyme’s manufacturing problems have incurred the wrath of the U.S. Food and Drug Administration (“FDA”). As a result of the manufacturing problems at the Allston plant, the Company recently entered into a consent decree with the FDA which included, inter alia, the following terms:

·An up-front disgorgement of past profits of $175 million;

·A requirement that Genzyme move “fill/finish” operations out of the Allston plant for Cerezyme, Fabrazyme and Thyrogen sold within the United States by November 28, 2010, and by August 31, 2011 for products sold outside the United States.  Should Genzyme not be able to meet these deadlines, the FDA can require the Company to disgorge 18.5 percent of revenue for these products;

·If Genzyme docs not meet certain milestones relative to the 2-3 year remediation plan, the FDA can require Genzyme to pay $15,000 per day, per affected drug, until compliance milestones are met; and

·Once the remediation plan is fully completed, FDA will require five years of oversight and annual reports submitted by a third party consultant.

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Sanofi’s Approach to Genzyme

33.For at least a month, Sanofi has been quietly pursuing the possibility of a friendly acquisition of Genzyme for a substantial premium. The New York Times reported on July 23, 2010 that Sanofi made a takeover approach to Genzyme two weeks prior and was “waiting for a reply.”

34.However, on July 26, 2010, it was reported that Genzyme had rebuffed Sanofi’s offer.

35.On July 28, 2010, in the wake of Genzyme’s rejection, it was reported that Sanofi’s board had authorized a formal bid of $70 per share or a total of $18.6 billion for the Company. Other industry speculation placed Sanofi’s likely offer anywhere between $67 and $75 dollars per share, which comports with analyst valuations. Lazard Capital Markets analyst William Tanner indicated “[f]undamentally, we estimate that Genzyme stock is worth $58 per share, but the stock may trade on a takeover basis and we view $73 as a reasonable price.” Genzyme shareholders agree.   According to Sam Isaly, managing partner of OrbiMed Advisors LLC, a long time investor that holds a 0.9% stake in Genzyme, “I suspect a figure in the $70 range will be enough.”

36.As reported by Bloomberg on August 3, 2010, the Genzyme Board has relented and entered into “talks” with Sanofi relating to a possible sale of the Company.

37.However, nearly two weeks later, nothing has emerged from these alleged discussions and, according to media reports, discussions may continue for weeks. The lack of urgency on the part of Genzyme to pursue a sale was underscored by one U.S. hedge manager who noted that he “wouldn’t be surprised if we didn’t see an offer until September with the August slowdown.”

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Genzyme’s Unwillingness to Engage in Good Faith Negotiations

38.Reports of protracted discussions between Sanofi and Genzyme, with no end in sight in light of the French holiday slowdown, provide Genzyme with a convenient cover for its true goal: to avoid a sale of the Company completely.

39.Defendant Termeer and the Board stubbornly refuse to genuinely and in good faith consider a sale of the Company that would maximize value for its public shareholders. In fact, Termeer has spent most of 2010 “telling people that his company…is determined to remain independent.”

40.In addition, the presence of so-called “activist” investor Carl Icahn, and his two appointees to the Board, has not guaranteed that the Board will consider Sanofi’s offer, or any other value-maximizing offer, in good faith. After doubling his stake in Genzyme to roughly 4.8 million shares, on February 22, 2010, Icahn announced that he would seek election of himself and three associates to the Company’s board at the annual shareholder meeting, and he appeared poised to push the Company towards a sale.

41.However, on June 9, 2010, on the eve of the shareholder vote, the Company announced that it had settled its proxy contest with Icahn. Pursuant to the settlement, Icahn agreed to withdraw his slate of four nominees for the Board and vote his Company stock in favor of the Company’s nominees. In exchange, the Company agreed to appoint Defendants Burakoff and Ende to serve as directors of the Company.

42.Media reports on the settlement of the proxy contest indicate that Defendant Whitworth helped to broker the “peace treaty” between Icahn and the Company. Commenting on the resolution, Whitworth stated: “It’s always good to have everyone inside the same tent.”

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43.Whitworth’s eagerness to squash Icahn’s aggressive push to sell the Company is understandable in light of the fact that Whitworth and Relational began buying stock in the Company in the third quarter of 2008, when it traded as high as $83.25.

44.Indeed, Whitworth has been portrayed in the media as a “long-term investor” who “bought much of his stock at higher prices and might have less financial incentive to push for a deal with Sanofi.”

45.Corralling Icahn was critical for Whitworth, as he holds over 10.6 million shares of Company stock according to Genzyme’s 2010 Proxy, a 4% stake in the Company, and he stands to lose a significant amount of money if the Company is sold in the reported range of Sanofi’s bid. As Capstone Global Markets merger arbitrage specialist Sachin Shah put it “Relational is looking at this, they’re saying, we’ve owned this a while, we owned it in the 80s, why would we sell?”

46.Icahn was apparently placated by the appointment of Defendants Burakoff and Ende to the Board, as he has mellowed from his aggressive push towards a sale of the Company and, instead, now supports the Board and Genzyme’s continued independent existence. Following the settlement of the proxy contest, Icahn noted: “I am always pleased when a proxy fight can be avoided. I believe Drs. Burakoff and Ende will add significant medical and financial expertise to the Genzyme board. I am also very heartened that the Genzyme board recently brought on Ralph Whitworth, a longtime activist, as a director, and announced that Dennis Fenton will shortly be added to the board as well.”

47.Identifying the addition of Defendants Burakoff, Ende, Whitworth, and Fenton to the Board as a good outcome for shareholders, Icahn stated, “New oversight at the director level will help this great company achieve its full potential.”

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48.Similarly, Termeer viewed the settlement of the proxy contest as an affirmation of Genzyme’s continued existence as an independent company: “This agreement provides a pragmatic and constructive solution that allows us to focus on continuing to strengthen and build the [C]ompany to create value for our shareholders.”

49.Termeer went on to state that after resolving the proxy contest, the Company wasn’t for sale and that it was, rather, focused on the future: “we can get away from that conflict and start to run the company again, moving forward with the very, very exciting developments we have ahead of us.”

Defendant Termeer’s Optimism is Unfounded.

50.On a personal level, Termeer noted that he plans to continue leading the Company until its manufacturing defects are resolved and, accordingly, he plans to step down in 2011.

51.Remarkably, as observed by The Boston Globe, Termeer is “fond of reminding people that Genzyme shares traded for as much as $83 each two years ago, and he believes his company’s stock can get back to those levels again.” This has led to speculation that “Genzyme would try to hold out for a minimum sale price in that range.”

52.Termeer’s confidence notwithstanding, there is little to indicate that such a quick recovery is likely. Even if the Company can distance itself from past manufacturing problems and, instead, benefit from positive reaction to its pipeline, Boston Globe business columnist Steven Syre indicated that this would take a “a steady stream of good news... probably a few years- to see Genzyme shares climb back near their old highs again.”

53.If it takes Genzyme shares three years to reach their potential, and Termeer is planning on stepping down in 2011, there is obvious uncertainty as to who would be running the Company in the final two years of its recovery. As Syre wondered: “who would be running the

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company during the final two [years]? The chief executive to be named later? That’s a lot to take on faith.”

54.In fact, a three year recovery period may be overly optimistic. A Company spokesman recently indicated that the Company estimates it will take “3 or 4 years to complete all the work in our remediation plan” for the Company’s manufacturing problems. In addition, according to the Wall Street Journal, “the three-to four-year process won’t actually begin until the plan is submitted to the FDA in the fourth quarter [of 2010].”

55.Yet there is no guarantee that the Company will resolve its manufacturing issues in this time frame, if at all.  Industry sources have recently acknowledged the risk Sanofi would be taking on in acquiring Genzyme “since it’s not clear whether Genzyme’s manufacturing problems have been resolved.” As recently as August 9, 2010, in a Form 10-Q filed with the SEC, the Company indicated that it had “identified additional inventories that did not meet our quality specifications. Our decision to discard these inventories has resulted in a second quarter write off of $6.5 million in addition to the $21.9 million write off previously reported” which resulted in a loss for the Company during this period. The Company identified the discarded drugs as Cerezyme, Fabrazyme, the thyroid medicine Thyrogen, and cholesterol drug Cholestagel.

56.Marc Booty, asset manager at Pictet Asset Management has noted “if Genzyme says ‘no’ [to Sanofi], they have to show investors how they will get the share price back to the price of the offer.  It will be difficult for them to say “We didn’t want to.” The fact is, with on-going manufacturing problems, a prolonged perhaps indefinite recovery period, and potential instability in its management structure moving forward, the Company cannot adequately explain to its shareholders how it plans to remain independent and raise its share value to the reported

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range of Sanofi’s bid, $67-$75, let alone the $83 price per share that Termeer quotes. Stated another way, the Company cannot adequately explain to its shareholders why it is failing to negotiate in good faith with Sanofi and, further, failing to engage in an open and honest process of evaluating a possible sale of the Company.

Board’s Failure to Engage Other Potential Bidders

57.The Board’s desire to avoid a sale of the Company, despite a potentially value-maximizing offer and the highly contingent nature of its recovery, is especially galling given the attention the Company has attracted from potential suitors other than Sanofi, including major pharmaceutical companies like GlaxoSmithKline (“GSK”) and Johnson & Johnson. GSK reportedly asked Genzyme to “keep it in mind if [it] considered selling itself.”

58.This is to say nothing of expected interest from large Japanese drug makers whom observers have identified as possible “wild cards” to enter the bidding for Genzyme. Indeed, in its July 26, 2010 report on Genzyme, Collins Stewart noted the interest the Company had attracted from pharmaceutical suitors and indicated that “a large-pharma-GENZ transaction could make strategic sense.”

59.Given such interest, a bidding war for Genzyme is possible. Underscoring shareholder desire for the Board to engage such interest to maximize value, Sven Borho of OrbiMed Advisors observed, “If two or three companies get involved in bidding, the $80s are achieved really easily.”

60.Media reports have similarly indicated that “the Company is likely to fetch $80 a share- or more- only if it can draw other suitors into a bidding war.” (emphasis added).

61.Shareholders are getting restless with the Board’s reluctance to actively embrace the possibility of selling the Company and engaging suitors in open, honest, and good faith

14

negotiations. As Mr. Borho indicated, “The Board has a duty to shareholders. If there’s a pretty significant bid coming, they have to take it seriously.”

62.Yet Genzyme and its Board appear content to engage in nominal “talks” with Sanofi for weeks on end, with no end in sight, through the French holiday. Such a drawn-out timetable is not the mark of a motivated Board acting in the best interest of its shareholders to maximize value. The Board has failed to act with the sense of urgency its public shareholders deserve, by either engaging Sanofi meaningfully and in a timely manner or, perhaps more fruitfully, taking steps to instigate a bidding war amongst major pharmaceutical companies.

COUNT I

AGAINST THE INDIVIDUAL DEFENDANTS FOR BREACH OF FIDUCIARY DUTY

63.Plaintiff repeats and realleges the allegations above as if fully set forth herein.

64.The Individual Defendants have a duty to maximize the Company’s value for the stockholders’ benefit. Thus, the Individual Defendants have an obligation to act in a neutral manner in order to get the highest value reasonably obtainable for the shareholders.

65.The Individual Defendants were and are under a duty:

(a)to engage in good faith negotiations and other actions with Sanofi and any other potential bidder to obtain the best possible offer for Genzyme and its stockholders;

(b)to act in the interests of the equity owners;

(c)to maximize shareholder value;

(d)to obtain the best financial and other terms when the Company’s independent existence could be materially altered by a transaction;

15

(e)to abstain from deploying any entrenchment and defensive measures to prevent Genzyme stockholders from receiving and accepting a valid and value-maximizing offer for their Genzyme shares; and

(f)to act in accordance with their fundamental duties of due care and loyalty.

66.The Individual Defendants cannot discharge their fiduciary duty by simply refusing to negotiate or failing to negotiate in good faith with Sanofi or any other potential bidder.

67.By the acts, transactions and courses of conduct alleged herein, the Individual Defendants, individually and as part of a common plan and scheme, are in breach of their fiduciary duties to Plaintiff and the other members of the Class and are attempting unfairly to deprive Plaintiff and other members of the Class of the opportunity to realize the full and fair value of their Genzyme shares. The Individual Defendants have been presented with the opportunity to pursue potential offers for all Genzyme shares at a substantial premium over the existing market price.  If the offers are not adequately pursued and the Individual Defendants fail to engage in good faith negotiations relative to these offers, Genzyme shareholders will be deprived of the opportunity for substantial gains on their investment in the Company and be irreparably damaged thereby.

68.By reason of the foregoing acts, practices and course of conduct, the Individual Defendants have failed to negotiate and investigate a potential sale of the Company in good faith in the exercise of their fiduciary obligations toward Plaintiff and the other Genzyme public stockholders.

69.As a result of the actions of the Individual Defendants, Plaintiff and the other members of the Class have been and will be damaged in that they will not have the opportunity

16

to receive their fair proportion of the value of Genzyme’s assets and businesses and will be prevented from obtaining appropriate consideration for their shares of Genzyme common stock.

70.Unless enjoined by this Court, the Individual Defendants will continue to breach their fiduciary duties owed to Plaintiff and the other members of the Class, which may lead to the withdrawal of a potential offer, which will prevent the Class from receiving its fair proportionate share of Genzyme’s valuable assets and businesses, and/or benefit them in the unfair manner complained of herein, all to the irreparable harm of the Class.

71.Plaintiff and the Class have no adequate remedy at law. WHEREFORE, Plaintiff demands judgment and preliminary and permanent relief, including injunctive relief, in its favor and in favor of the Class and against defendants as follows:

A.Declaring that this action is properly maintainable as a class action;

B.Declaring and decreeing that the Individual Defendants have breached their fiduciary duties to the Plaintiff and Genzyme stockholders by their failure to adequately inform themselves regarding the potential offer by Sanofi and/or any additional offer, and their failure to pursue the best available transaction for Genzyme stockholders.

C.Enjoining defendants’ defensive maneuvers or other defensive tactics designed to prevent Genzyme stockholders from receiving and accepting a valid and value-maximizing offer for their Genzyme shares;

D.Directing the Individual Defendants to exercise their fiduciary duties to obtain a transaction which is in the best interests of shareholders, including negotiating fully and in good-faith with Sanofi and/or any other entity;

E.Awarding Plaintiff and the Class appropriate damages;

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F.Awarding Plaintiff the costs and disbursements of this action, including reasonable attorneys’ and experts’ fees;

G.Granting such other and further relief as this Court may deem just and proper.

JURY TRIAL DEMANDED

Plaintiff hereby demands a trial by jury.

Dated: August 16, 2010	By its attorneys,
	GILMAN AND PASTOR, LLP
	/s/ David Pastor
	David Pastor (BBO #391000)
	63 Atlantic Avenue, 3rd Floor
	Boston, MA 02110
	Telephone:    (617) 742-9700
	Facsimile:      (617) 742-9701
	dpastor@gilmanpastor.com

Of Counsel:

BARROWAY TOPAZ KESSLER

MELTZER & CHECK, LLP

Marc A. Topaz

Lee D. Rudy

Michael C. Wagner

J. Daniel Albert

J. Quinn Kerrigan

280 King of Prussia Road

Radnor, Pennsylvania 19087

Telephone: (610) 667-7706

Attorneys for Plaintiff

Chester County Employees Retirement Fund

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EX-99.(A)(10)

Exhibit (a)(10)

COMMONWEALTH OF MASSACHUSETTS

MIDDLESEX, SS	SUPERIOR COURT DEPARTMENT OF THE TRIAL COURT
ALAN R. KAHN, on Behalf of Himself and All Other Similarly Situated Shareholders of Genzyme Corporation,	DOCKET NO. 10-3067
Plaintiff,	CLASS ACTIONCOMPLAINT
v.
HENRI TERMEER, DOUGLAS	JURY TRIAL DEMANDED
BERTHIAUME, ROBERT BERTOLINI, GAIL
BOUDREAUX, STEVEN BURAKOFF,
ROBERT CARPENTER, CHARLES L.
COONEY, VICTOR DZAU, ERIC ENDE,
DENNIS FENTON, COMIE MACK III,
RICHARD F. SYRON AND RALPH
WHITWORTH, GENZYME CORPORATION
and SANOFI-AVENTIS, S.A.

Defendants.

Plaintiff Alan R. Kahn (“Plaintiff’), by and through his undersigned counsel, makes the following allegations upon information and belief, except as to those allegations specifically pertaining to Plaintiff, which are predicated upon the investigation undertaken by Plaintiff’s counsel.

NATURE OF THE ACTION

1. This is a shareholder class action brought by Plaintiff on behalf of himself and all other similarly situated public shareholders of Genzyme Corporation (“Genzyme” or the “Company”) against the Company and its Board of Directors (the “Individual Defendants”), among others, to enjoin defendants from breaching their fiduciary duties in the proposed buyoutof Genzyme by Sanofi-Aventis (“Sanofi”) (the “Proposed Transaction”)

2

under which Sanofi has proposed to acquire Genzyme for $69 cash per share, or approximately $18.4 billion in the aggregate. The Proposed Transaction is unfair both with respect to price and process and is designed to benefit Genzyme’s insiders to the detriment of Plaintiff and the Class.

JURISDICTION AND VENUE

2.             This Court has jurisdiction over each defendant named herein because each defendant is either a corporation that conducts business in and maintains operations in this County, or is an individual who is a director of a corporation headquartered in Middlesex County and otherwise has sufficient minimum contacts with Massachusetts so as to render the exercise of jurisdiction by the Massachusetts courts permissible under traditional notions of fair play and substantial justice.

3.             Venue is proper in this Court because one or more of the defendants either resides in or maintains executive offices in Middlesex County, a substantial portion of the transactions and wrongs complained of herein, including the Individual Defendants’ breaches of their fiduciary duties owed to Genzyme shareholders occurred in Middlesex County, and defendants have received substantial compensation in this County by doing business here and engaging in numerous activities that had an effect in this County.

THE PARTIES

4.             Plaintiff is and was, at all times relevant hereto, a holder of Genzyme common stock.

5.             Defendant Genzyme is a corporation organized and existing under the laws of the Commonwealth of Massachusetts, with its principal executive offices located at 500 Kendall

Street, Cambridge, Massachusetts 02142. At all relevant times, the Company’s shares traded on the NASDAQ stock exchange under the symbol “GENZ.”.

6.             Defendant Henri Termeer (“Termeer”) is and has been president, chief executive officer and chairman of the board since 1983, 1985 and 1988, respectively. Termeer is also a member of both the Risk Oversight Committee and Strategic Planning and Capital Allocation Committee.

7.             Defendant Douglas Berthiaume (“Berthiaume”) is and has been a director of the Company since 1998. Berthiaume is a member of the both the Compensation Committee and the Nominating/Governance Committee.

8.             Defendant Robert Bertolini (“Bertolini”) is and has been a director of the Company since 2009. Bertolini is also Chair of the Audit Committee and a member of the Strategic Planning and Capital Allocation Committee.

9.             Defendant Gail Boudreaux (“Boudreaux”) is and has been a director of the Company since 2004. Boudreaux is Chair of the Risk Oversight Committee and a member of the Audit Committee.

10.           Defendant Steven Burakoff (“Burakoff’) is and has been a director of the Company since 2010. Burakoff is a member of both the Compensation Committee and Risk Oversight Committee. Burakoff was given his seat on the board as part of an agreement to settle a proxy fight with Carl C. Icahn.

11.           Defendant Robert Carpenter (“Carpenter”) is and has been a director of the Company since 1994. Carpenter is a member of the Compensation Committee and the Strategic Planning and Capital Allocation Committee.

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12.           Defendant Charles L. Cooney (“Cooney”) is and has been a director of the Company since 1983. Cooney is Chair of the Compensation Committee and a member of the Nominating/Governance Committee.

13.           Defendant Victor Dzau (“Dzau”) is and has been a director of the Company since 2000. Dzau is a member of the Compensation Committee and the Risk Oversight Committee.

14.           Defendant Eric Ende (“Ende”) is and has been a director of the Company since 2010. Ende is a member of the Audit Committee and the Risk Oversight Committee. Ende was given his seat on the board as part of an agreement to settle a proxy fight with Carl C. Icahn.

15.           Defendant Dennis Fenton (“Fenton”) is and has been a director of the Company since 2010. Fenton is a member of the Audit Committee and the Risk Oversight Committee. Fenton was given his seat on the board as part of a mutual cooperation agreement with Relational Investors LLC.

16.           Defendant Connie Mack III (“Mack”) is and has been a director of the Company since 2001. Mack is Chair of the Nominating/Governance Committee and a member of the Audit Committee.

17.           Defendant Richard F. Syron (“Syron”) is and has been a director of the Company since 2006. Syron is a member of the Audit Committee and the Nominating/Governance Committee.

18.           Defendant Ralph Whitworth (“Whitworth”) is and has been a director of the Company since 2010. Whitworth is Chair of the Strategic Planning and Capital Allocation Committee and a member of the Compensation Committee and the Nominating/Governance Committee. Whitworth was given his seat on the board as part of a mutual cooperation agreement with Relational Investors LLC.

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19.             Defendants Termeer, Berthiaume, Bertolini, Boudreaux, Burakoff, Carpenter, Cooney, Dzau, Ende, Fenton, Mack, Syron and Whitworth are referred to herein collectively as the “Individual Defendants.”

20.             Defendant Sanofi is one of the world’s largest pharmaceutical companies, ranking number one in Europe. In the U.S., Sanofi currently ranks among the top five pharmaceutical companies with leading positions in seven major therapeutic areas: cardiovascular, thrombosis, oncology, metabolic diseases, central nervous system, internal medicine, and vaccines. Sanofi shares are listed in Paris (EURONEXT: SAN) and in New York (NYSE: SNY). The corporate headquarters are based in Paris, France. The headquarters of its U.S. organization are based in Bridgewater, New Jersey.

CLASS ACTION ALLEGATIONS

21.             Plaintiff brings this action on behalf of himself and all other shareholders of the Genzyme (except the Defendants herein and any persons, firm, trust, corporation, or other entity related to or affiliated with them and their successors in interest), who are, or will be, threatened with injury arising from Defendants’ actions, as more fully described herein.

22.             This action is properly maintainable as a class action for the following reasons:

(a)             The Class is so numerous that joinder of all members is impracticable. As of January 29, 2010, there were over 266 million shares issued and outstanding of Genzyme common stock. Upon information and belief, Genzyme common stock is owned by thousands of shareholders of record nationwide.

(b)             Plaintiff is committed to prosecuting this action and has retained competent counsel experienced in litigation of this nature. Plaintiff’s claims are typical of the claims of the other members of the Class and Plaintiff has the same interests as the other

5

members of the Class. Plaintiff is an adequate representative of the Class and will fairly and adequately protect the interests of the Class.

(c)           The prosecution of separate actions by individual members of the Class would create the risk of inconsistent or varying adjudications with respect to individual members of the Class, which would establish incompatible standards of conduct for defendants, or adjudications with respect to individual members of the Class that would, as a practical matter, be dispositive of the interests of the other members not parties to the adjudications or substantially members or impede their ability to protect their interests.

(d)           To the extent Defendants take further steps to effectuate the Proposed Transaction, preliminary and final injunctive relief on behalf of the Class as a whole will be entirely appropriate because Defendants have acted, or refused to act, on grounds generally applicable and causing injury to the Class.

23. There are questions of law and fact that are common to the Class and that predominate over questions affecting any individual class member. The common questions include, inter alia, the following:

(a)             Whether Defendants breached their fiduciary duties of due care, good faith, and loyalty with respect to Plaintiff and the other members of the Class as a result of the conduct alleged herein;

(b)             Whether the process implemented and set forth by the Defendants for the Proposed Transaction, including but not limited to, the Merger Agreement, the negotiations concerning the Merger Agreement, and the shareholder approval process provided for the Proposed Transaction, is entirely fair to the members of the Class;

6

(c)           Whether the Individual Defendants have breached their fiduciary duty of candor by failing to disclose all material facts related to the Proposed Transaction;

(d)           Whether Sanofi aided and abetted the Individual Defendants’ breaches of fiduciary duties of candor, due care, good faith, and loyalty with respect to Plaintiff and the other members of the Class as a result of the conduct alleged herein; and

(e)           Whether Plaintiff and the other members of the Class would be irreparably harmed if Defendants are not enjoined from effectuating the conduct described herein. SUBSTANTIVE ALLEGATIONS

24.           Genzyme was founded as a small start-up in 1981, and has grown into a leading international biotech company, with over 12,000 employees and revenues of $4.5 billion in 2009. Genzyme’s products and services are sold to patients in approximately 100 countries. The company’s products and services are focused on rare inherited disorders, kidney disease, orthopaedics, cancer, transplant and immune disease, and diagnostic testing.

25.           On August 2, 2010, numerous media outlets reported that Sanofi proposed to acquire Genzyme for $69 cash per share, or approximately $18.4 billion in the aggregate.

26.           Despite Genzyme’s general struggles since it announced last year that it detected contamination at a Massachusetts based manufacturing facility, which resulted in worldwide shortages of two of its top products, Gaucher disease treatment Cerezyme and Fabry disease therapy Fabrazyme, and ultimately lead to various shareholder derivative suits, the Company is poised to benefit tremendously once these issues are resolved.

27.           In the article, “Genzyme’s Hidden Value,” Matthew Herper, a senior editor at Forbes, stated that, “[t]he manufacturing mess makes it possible that [Genzyme’s] long time

7

chief executive, Henri Termeer, might be dislodged. But more importantly, settling it could result in a rapid increase in earnings that makes Genzyme an ideal fit for a needy drug maker.”

28.           Genzyme also has a very strong product pipeline. The Company has some promising late-stage drugs like Campath for multiple scelerois and mipomersen for cholesterol.

29.           It comes as no surprise that analysts see value in the Company. Analyst Stephen Simpson, CFA, of Investopedia. corn, has stated, “if Genzyme ultimately gets approval for Campath and mipomersen, the stock is probably worth something north of the high $80’s.” Also, Sven Borho , an analyst with OrbiMed Advisors, a company which holds over 2.5 million shares of Genzyme, was recently quoted on Bloomberg.com stating that, “[i]f two or three companies get involved in bidding, the $80s are achieved really easily . . . [t]here are so few good assets out there, and this is one of the more promising assets.”

30.           Genzyme is also in a position to benefit from the Centers for Medicare and Medicaid Services final bundling rule on the end-stage renal disease prospective payment system. Biard analyst Christopher J. Raymond said in a research note that he sees the complex, 923-page rule as a positive for Genzyme.

31.           In their role as directors of a corporation, the Individual Defendants have fiduciary obligations to: (a) undertake an appropriate evaluation of Genzyme’s net worth as a merger/acquisition candidate; (b) act independently to protect the interests of the Company’s public shareholders; (c) adequately ensure that no conflicts of interest exist between the Individual Defendants’ own interests and their fiduciary obligations, and, if such conflicts exist, to ensure that all conflicts are resolved in the best interests of Genzyme’s public shareholders; and (d) actively evaluate the Proposed Transaction and engage in a meaningful auction with third parties in an attempt to obtain the best value on any sale of Genzyme.

8

32.             Based on a preliminary valuation using publicly available information, the consideration offered in the Proposed Transaction is inadequate. Prior to the current economic downturn and manufacturing problems, the stock was trading higher than the $69 offered in the Proposed Transaction. The expectation is that with the new federal healthcare legislation and FDA approval of the drugs in Genzyme’s pipeline, the Company’s value will continue to increase.

33.             This proposed consideration is inadequate and unfair to Plaintiff and the Class because, in reality, it offers a small premium, does not reflect the Company’s potential growth value, and thereby deprives Plaintiff and the Class of the true and full value of their shares.

34.             The consideration to be paid to Plaintiff and the Class in the Proposed Transaction is also unfair and grossly inadequate because, among other things, the intrinsic value of Genzyme is materially in excess of the amount offered in the Proposed Transaction, giving due consideration to the Company’s anticipated operating results, net asset value, cash flow profitability, and established markets.

35.           Additionally, four of the directors are beholden to outside influences from activist shareholders. Defendants Burakoff and Ende were given seats on the board as part of a settlement with Carl C. Icahn. Similarly, Defendants Fenton and Whitworth were given seats as the board as part of a mutual cooperation agreement with Relational Investors LLC. These Defendants are not acting in the bests interest of shareholders, but rather in the interest of the activist shareholders.

36.           The Proposed Transaction will deny Class members their right to share proportionately and equitably in the true value of Company’s valuable and profitable business,

9

and future growth in profits and earnings, at a time when the Company is poised to increase its profitability.

COUNT I

Claim for Breach of Fiduciary Duties
Against the Individual Defendants

37.           Plaintiff repeats and realleges each and every allegation set forth herein.

38.           The Individual Defendants have violated the fiduciary duties owed to the public shareholders of Genzyme and have acted to put their personal interests ahead of the interests of Genzyme shareholders or acquiesced in those actions by fellow Defendants. These Defendants have failed to take adequate measures to ensure that the interests of Genzyme’s shareholders are properly protected and have embarked on a process that avoids competitive bidding and provides Sanofi with an unfair advantage.

39.           By the acts, transactions, and courses of conduct alleged herein, these Defendants, individually and acting as a part of a common plan, will unfairly deprive Plaintiff and other members of the Class of the true value of their Genzyme investment. Plaintiff and other Members of the Class will suffer irreparable harm unless the actions of these Defendants are enjoined and a fair process is substituted.

40.           The Individual Defendants have breached their duties of loyalty, entire fairness, good faith, and care by not taking adequate measures to ensure that the interests of Genzyme’s public shareholders are properly protected from over-reaching by Sanofi.

41.           By reason of the foregoing acts, practices, and courses of conduct, the Individual Defendants have failed to exercise due care and diligence in the exercise of their fiduciary obligations toward Plaintiff and the other members of the Class.

10

42.             As a result of the actions of Defendants, Plaintiff and the Class have been, and will be, irreparably harmed in that they have not, and will not, receive their fair portion of the value of Genzyme’s stock and businesses, and will be prevented from obtaining a fair price for their common stock.

43.             Unless enjoined by this Court, the Individual Defendants will continue to breach the fiduciary duties owed to Plaintiff and the Class and may consummate the Proposed Transaction to the disadvantage of the public stockholders, without providing sufficient information to enable Genzyme’s public shareholders to cast informed votes on the Proposed Transaction.

44.             The Individual Defendants have engaged in self-dealing, have not acted in good faith to Plaintiff and the other members of the Class, and have breached, and are breaching, fiduciary requirements to the members of the Class.

45.           Plaintiff and members of the Class have no adequate remedy at law. Only through the exercise of this Court’s equitable powers can Plaintiff and the Class be fully protected from the immediate and irreparable injury which these actions threaten to inflict.

COUNT II

Claim Against Sanofi for Aiding and Abetting
the Individual Defendants’ Breaches of Fiduciary Duties

46.           Plaintiff repeats and realleges each and every allegation set forth herein.

47.           The Individual Defendants breached their fiduciary duties to the Genzyme stockholders by the actions alleged supra.

48.           Such breaches of fiduciary duties could not, and would not, have occurred but for the conduct of Defendant Sanofi, which, therefore, aided and abetted such breaches through entering into the Proposed Transaction between Genzyme and Sanofi.

11

49.           Defendant Sanofi had knowledge that it was aiding and abetting the Individual Defendants’ breaches of fiduciary duties to Genzyme stockholders.

50.           Defendant Sanofi rendered substantial assistance to the Individual Defendants in their breaches of their fiduciary duties to Genzyme stockholders.

51.           As a result of Sanofi’s conduct of aiding and abetting the Individual Defendants’ breaches of fiduciary duties, Plaintiff and the other members of the Class have been, and will be, damaged in that they have been, and will be, prevented from obtaining a fair price for their shares.

52.           As a result of the unlawful actions of Defendant Sanofi, Plaintiff and the other members of the Class will be irreparably harmed in that they will be prevented from obtaining the fair value of their equity ownership in the Company. Unless enjoined by the Court, Sanofi will continue to aid and abet the Individual Defendants’ breaches of their fiduciary duties owed to Plaintiff and the members of the Class, and will aid and abet a process that inhibits the maximization of stockholder value and the disclosure of material information.

53.           Plaintiff and the other members of the Class have no adequate remedy at law. Only through the exercise of this Court’s equitable powers can Plaintiff and the Class be fully protected from immediate and irreparable injury which Defendants’ actions threaten to inflict.

PRAYER FOR RELIEF

WHEREFORE, Plaintiff demands judgment and preliminary and permanent relief, including injunctive relief, in his favor and in favor of the Class, and against the Defendants as follows:

A.              Certifying this case as a class action, certifying Plaintiff as class representative and their counsel as class counsel;

12

B.            Declaring that the conduct of the Individual Defendants in approving the Proposed Transaction and failing to negotiate in good faith with Sanofi and other acts and omissions set forth herein are breaches of the Individual Defendants’ fiduciary duties;

C.            Preliminarily and permanently enjoining the Individual Defendants from placing their own interests ahead of the interests of the Company and its shareholders;

D.            Preliminarily and permanently enjoining the Individual Defendants from initiating any defensive measures that would inhibit the Individual Defendants’ ability to maximize value for Genzyme shareholders;

E.             Awarding Plaintiff and the Class appropriate compensatory damages;

F.             Awarding Plaintiff the costs, expenses, and disbursements of this action, including any attorneys’ and experts’ fees and, if applicable, pre judgment and post-judgment interest; and

G.            Awarding Plaintiff and the Class such other relief as this Court deems just, equitable, and proper.

Dated: August 16, 2010	MATORIN LAW O CE, LLC
	By:
	Mitchell J. Mat. (BBO# 6493
	200 Highland Avenue, Suite 306
	Needham, Massachusetts 02494
	Tel: (781) 453-0100
	Fax: (888) 628-6746
	E-Mail : mmatorin@matorinlaw.com

13

GARDY & NOTIS, LLP

Mark C. Gardy

James S. Notis

Charles A. Germershausen

560 Sylvan Avenue

Englewood Cliffs, New Jersey 07632

Tel: 201-567-7377

Fax: 201-567-7337

Counsel for Plaintiff

14

EX-99.(A)(11)

Exhibit (a)(11)

COMMONWEALTH OF MASSACHUSETTS

MIDDLESEX, SS SUPERIOR COURT DEPARTMENT

DAVID SHADE, on behalf of himself and all others similarly situated,                                                                 Plaintiff, against Genzyme Corporation, Henri Termeer, Douglas Berthiaume, Robert Bertolini, Gail Boudreaux, Steven Burakoff, Robert Carpenter, Charles L. Cooney, Victor Dzau, Eric Ende, Dennis Fenton, Connie Mack III, Richard F. Syron, and Ralph Whitworth,                                                                 Defendants. DOCKET NO. CLASS ACTION COMPLAINT Jury Trial Demanded FILED IN THE OFFICE OF THE CLERK OF COURTS FOR THE COUNTY OF MIDDLESEX AUG 31 2010 [ILLEGIBLE]

Plaintiff, David Shade (“Plaintiff”), by his undersigned attorneys, as and for his class action complaint, alleges as follows, based upon information and belief and the investigation of his counsel, except for any allegations as to himself, which are based upon his personal knowledge:

1

Nature of Action

1.This is a shareholder class action brought by Plaintiff on behalf of himself and all shareholders of Genzyme Corporation (“Genzyme” or the “Company”), with certain exceptions as discussed below, seeking injunctive and other equitable relief to require Defendants to negotiate in good faith with Sanofi-Aventis, S.A. (“Sanofi”) and any other potential bidders, and to take any steps that would result in Genzyme shareholders obtaining maximum value for their shares.

2.On about August 2, 2010, according to press reports, Sanofi made an offer to purchase all the outstanding shares of Genzyme for approximately $69 per share, for a total purchase price of $19 billion.

3.Since that time, according to press reports, Genzyme has refused to provide Sanofi with due diligence materials, and has effectively refused to engage in any negotiations.

4.Genzyme’s refusal to negotiate in good faith with Sanofi, and its failure to take any other steps to put the Company up for sale at this time, is consistent with the actions of the majority of Genzyme’s board, which has repeatedly taken steps to entrench itself at the expense of Genzyme’s shareholders, as further discussed below.

5.Plaintiff brings this action in order to ensure that Genzyme’s board of directors negotiates in good faith with Sanofi and any other potential bidders, takes steps which will result in the maximization of shareholder value, and prevent the Defendants from putting their personal interests first, and entrenching themselves.

Jurisdiction and Venue

6.This Court has subject matter jurisdiction over this state law matter, and personal jurisdiction over each Defendant as each Defendant does business in this state and this

2

judicial district, and this is the place where the acts giving rise to the cause of the action occurred.

7.Venue is proper in this judicial district as one or more of the Defendants either resides or maintains executive offices in this county, and a substantial portion of the wrongs complained of herein occurred, and are occurring in this county.

The Parties

8.Plaintiff is and at all relevant times was a holder of Genzyme shares.

9.Defendant Genzyme is a corporation organized and existing under the laws of the Commonwealth of Massachusetts, and maintains its principal place of business at 500 Kendall Street, Cambridge, Massachusetts 02142.

10.Defendant Henri Termeer (“Termeer”) is and has been the president, chief executive officer and chairman the board of Genzyme since the 1980’s. Termeer is also a member of the Company’s Risk Oversight Committee and Strategic Planning and Capital Allocation Committee. In recent time, Termeer has been engaged in fighting a proxy solicitation launched by Carl Icahn (“Icahn”) and several of his investment entities, and came to a compromise with Icahn, among others, in order to retain his position, and that of a number of the other long time Genzyme board members.

11.Defendant Douglas Berthiaume (“Berthiaume”) is and has been a director of the Company since 1998. Berthiaume is a member of both the Compensation Committee and the Nominating/Governance Committee.

12.Defendant Robert Bertolini (“Bertolini”) is and has been a director of the Company since 2009. Bertolini is also Chair of the Audit Committee and a member of the Strategic Planning and Capital Allocation Committee.

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13.Defendant Gail Boudreaux (“Boudreaux”) is and has been a director of the Company since 2004. Boudreaux is Chair of the Risk Oversight Committee and a member of the Audit Committee.

14.Defendant Steven Burakoff (“Burakoff”) is and has been a director of the Company since 2010. Burakoff is a member of both the Compensation Committee and Risk Oversight Committee, and was given a board seat in a compromise with Icahn, who agreed to forego a proxy fight if Burakoff was provided a seat.

15.Defendant Robert Carpenter (“Carpenter”) is and has been a director of the Company since 1994. Carpenter is a member of the Compensation Committee and the Strategic Planning Allocation Committee.

16.Defendant Charles L. Cooney (“Cooney”) is and has been a director of the Company since 1983. Cooney is Chair of the Compensation Committee and a member of the Nominating/Governance Committee.

17.Defendant Victor Dzau (“Dzau”) is and has been a director of the Company since 2000. Dzau is a member of the Compensation Committee and the Risk Oversight Committee.

18.Defendant Eric Ende (“Ende”) is and has been a director of the Company since 2010. Ende is a member of the Audit Committee and the Risk Oversight Committee, and was given his seat on the board as part of the agreement with Icahn to settle his proxy fight, and support the remainder of the current board.

19.Defendant Dennis Fenton (“Fenton”) is and has been a director of the Company since 2010. Fenton is a member of the Audit Committee and the Risk Oversight Committee. Fenton was given his seat on the board as part of an agreement with activist

4

shareholder Ralph Whitworth (“Whitworth”) and Relational Investors, LLC (“Relational”), in which Relational agreed to support the current board.

20.Defendant Connie Mack III (“Mack”) is and has been a director of the Company since 2001. Mack is the Chair of the Nominating/Governance Committee and a member of the Audit Committee.

21.Defendant Richard F. Syron (“Syron”) is and has been a director of the Company since 2006. Syron is a member of the Audit Committee and the Nominating/Governance Committee.

22.Defendant Ralph Whitworth (“Whitworth”) is and has been a director of the Company since 2010. Whitworth is Chair of the Strategic Planning and Capital Allocation Committee and a member of the Compensation Committee and the Nominating/Governance Committee. Whitworth was given his seat on the board as part of the mutual cooperation agreement with Relational.

23.Defendants Termeer, Berthiaume, Bertolini, Boudreaux, Burakoff, Carpenter, Cooney, Dzau, Ende, Fenton, Mack, Syron, and Whitworth are hereinafter collectively referred to as the “Defendants”. Defendants Burakoff, Ende, Fenton and Whitworth are hereinafter referred to as the “Activist Directors”.

24.Non-party Sanofi is one of the work’s largest pharmaceutical companies, ranking number one in Europe. In the U.S., Sanofi currently ranks among the top five pharmaceutical companies with leading positions in seven major therapeutic areas: cardiovascular, thrombosis, oncology, metabolic diseases, central nervous system, internal medicine, and vaccines. Sanofi trades on the New York Stock Exchange as well as the Euronext.

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Class Allegations

25.Plaintiff brings this action on behalf of himself and as a class action, pursuant to Rule 23 of the Massachusetts Rules of Civil Procedure, on behalf of all shareholders of Genzyme (except the Defendants and any person, entity, agent, subsidiary, affiliate, family member, or trust related to any one of the Defendants).

26.This action is properly maintained as a class action for the following reasons:

a.The Class is so numerous that joinder of all Class members is impracticable. As of January 29, 2010, there were over 266 million shares of Genzyme stock issued and outstanding.

b.Plaintiff is committed to prosecuting this action and has retained competent counsel experienced in litigation of this nature. Plaintiff’s claims are typical of the claims of other members of the Class and Plaintiff has the same interests as the other members of the Class. Plaintiff is an adequate representative of the Class and will fairly and adequately protect the interests of the Class.

27.The prosecution of separate actions by individual members of the Class would create the risk of inconsistent or varying adjudications with respect to individual members of the Class, which would establish incompatible standards of conduct for Defendants, or adjudications with respect to individual members of the Class that would, as a practical matter, be dispositive of the interests of the other members not parties to the adjudications or substantially members or impede their ability to protect their interests.

28.To the extent that Defendants take further steps to entrench themselves, fail to negotiate in good faith with Sanofi or any other potential bidders, and institute measures

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directed at thwarting any unsolicited bid for the Company, Defendants have acted on grounds generally applicable to, and causing injury to, the Class and, therefore, preliminary and final injunctive relief on behalf of the Class, as a whole, is appropriate.

29.There are questions of law and fact that are common to the Class and that predominate over any questions affecting any individual Class member. The common questions include:

a.Whether Defendants breached their fiduciary duties of due care, good faith, candor and loyalty to Plaintiff and other members of the Class as a result of the conduct alleged herein;

b.Whether the process in which the Defendants have engaged, in which they have refused to negotiate or provide due diligence to Sanofi, and have failed to take other steps to shop the Company despite the fact that Sanofi has indicated that it may well make a hostile bid, and the Company is in play, is a breach of their fiduciary duties;

c.Whether the Director Defendants are placing their own interests, in attempting to entrench themselves in their positions, over the interests of Class members in seeing the value of their shares maximized;

d.Whether Plaintiff and other Class members will be irreparably harmed if Defendants are not caused to enter into good faith negotiations with Sanofi, and to take other steps which would maximize shareholder value.

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30.Plaintiff does not anticipate any problems with the management of this action as a class action and a class action is the most efficient means to litigate this action.

Substantive Allegations

Termeer and the Current Board Mismanage Genzyme

31.Genzyme was founded as a small start up company in 1981, and has grown into a leading international biotechnology company, with over 12, 000 employees and revenues of over $4.5 billion in 2009.

32.Its products are sold to patients in over 100 countries, and its focus in on products that relate to niche and rare inherited disorders, kidney disease, orthopedics, cancer, transplants and immune diseases.

33.Over the past several years, however, Genzyme’s growth and revenues have suffered due to the mismanagement of Termeer, and many long standing members of the current board.

34.Commencing in at least as early as mid-2007, for instance, the board started receiving letters from the Food and Drug Administration (the “FDA”) regarding the contamination of certain of the Company’s drug manufacturing facilities.

35.By 2008, the Company had received a letter from the FDA specifically discussing contamination of the Company’s manufacturing facility in Allston, Massachusetts.

36.These letters went unheeded by the board.

37.Thus, by late 2009, the FDA had commenced an investigation and inspection of Genzyme’s Allston plant, and in November 2009, issued a finding that the plant suffered from 49 instances of manufacturing deficiencies.

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38.The plant was subsequently shut down, which in turn, touched off shortages for Genzyme’s drugs for rare genetic disorders including Gaucher, Pompe and Fabry diseases, which impacted significantly on the Company’s sales and revenues.

39.The shut down further opened the door for competing therapies to enter the market on an emergency basis.

40.Although the Company attempted to clean up the manufacturing situation, in fact, it lead to more FDA citations, and on March 24, 2010, Termeer, among other Genzyme executives entered into a consent decree with FDA.

41.By way of the Consent Decree, Genzyme was made to pay a $175 million fine composed of past profits, limit its distribution of certain products, move certain of its operations out of the Allston plant, and implement a comprehensive remediation plan to improve quality and compliance at the Allston plant, which will take anywhere from two to three years.

42.The FDA further imposed certain milestones on Genzyme, which if not met, will result in the Company paying fines of up to $15,000 per day for a period of seven to eight years.

43.As a consequence of this manufacturing blunder and the fall out therefrom, Genzyme was and remains the subject of numerous class and derivative action lawsuits.

Termeer and the Current Board Attempt to Entrench Themselves

44.In response to this massive mismanagement disaster, Genzyme’s activist and largest shareholders, Icahn and Ralph Whitworth of Relational, started making public statements about Termeer’s inability to manage the Company, suggesting that he should be replaced in the June 2010 election.

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45.Consistent with these statements, both Relational and Icahn began to accumulate Genzyme stock, and making public statements suggesting that they were taking steps toward a proxy fight to remove Termeer and others on the board.

46.Termeer, in an effort to entrench himself and other long standing board members, in turn, sought to prevent a proxy fight by reaching out to Relational and entering into a compromise which would keep Relational from gaining more power and using that power to remove him and other long standing board members.

47.This compromise agreement, entered into in January 2010, provided Whitworth, and another Relational nominee, Fenton, with board positions, on an expanded 10 member board, in exchange for which Relational agreed, among other things, that it would vote for Genzyme’s slate of directors, it would enter into a standstill agreement preventing it from obtaining additional shares, it would not use its power to encourage the solicitation of proxies, and it would not work with any third party in trying to control or influence the board.

48.As a consequence, Termeer and the remaining long-term board members were effectively able to lock up Relational and keep it from taking actions that would result in their removal.

Icahn Seeks to Remove Termeer and Long Standing Board Members

49.Some time in late 2009, Icahn also commenced accumulating Genzyme shares, and in February 2010, sent a letter to the board stating his intention to nominate four directors.

50.Immediately thereafter, Genzyme amended its agreement with Relational, reaffirming that it would continue to vote its shares for Genzyme’s slate, including Termeer.

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51.Through the spring of 2010, Termeer and Icahn engaged in a public battle through SEC filings, in which Icahn made clear his belief that Termeer and other long standing board members had severely damaged the Company, through their improper supervision of the Company’s manufacturing facilities, among other things, and that the Company was performing significantly worse than its peers.

52.This public fight culminated in an SEC filings, including a filing by Icahn on about May 26, 2010 of a scathing Definitive Statement on Form 14A (the “Proxy Statement”).

53.The Proxy Statement contained a presentation, entitled “Genzyme: Time to Change the Old Guard”, in which Icahn detailed how and why Termeer and the then current board had engaged in “extreme mismanagement”, and the damage they had caused to Genzyme.

54.Icahn noted that:

a.The Company had suffered severe manufacturing problems, of which the board had notice but apparently ignored;

b.These severe manufacturing problems had disrupted the Company’s relationship with the FDA, which now needed to be normalized; and

c.The key to the Company’s profitability was to get its plants back to running.

55.The Proxy Statement further noted that Genzyme’s stock had consistently underperformed its peers for over five years that management had overpromised but underperformed, that its efforts at fixing the Company’s issues remain unresolved, and worst of all, that due to management’s failure to properly oversee the Company, it had suffered a “manufacturing disaster of epic proportion.”

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56.Icahn then set forth at least 11 ways in which the board, including Termeer, had failed in its oversight role including failing to prevent FDA actions, failing to anticipate potential problems, failing to plan for operational redundancy, failing to build sufficient inventory reserves, failing to adequately disclose the magnitude of problems, failing to supply accurate timeliness for resolution of the above issues, failing to effectively deploy capital, failing to compensate employees relative to performance, continuing to fail to resolve problems despite years of warning letters from the FDA, all of which resulted in the destruction of shareholder value.

57.Icahn supported these contentions with a timeline setting forth the “History of FDA Warnings & Manufacturing Problems” demonstrating that Genzyme’s board and management knew since at least February 2009 about problems with the Allston plant and had received even earlier warnings about the board’s monitoring problems but had failed to adequately address these issues.

58.The Proxy Statement concluded that management, including Termeer had “clearly NOT adequately addressed manufacturing issues” , as recently as April 2010, that Genzyme was stills unable to meet demand for its products, and that under Termeer’s rein, the Company lost significant long terms shareholder value, including a loss of the confidence of the FDA and the Company’s clients.

59.Icahn then urged shareholders to “allow [the] Icahn slate to help fix this `broken’ company”, by increasing monitoring, selling off non-core portions of the Company, permanently resolving the manufacturing issues, and repairing the Company’s tarnished image. Icahn urged shareholder to change the “corporate culture from the top”, including removing Terrneer, Cooney, Mack and Sryron—long time and entrenched directors.

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60.As to the rest of the board, the Proxy Statement explained that the “Board Has Become Stagnant With Too Many Long-Standing Members”, and contained a graph demonstrating that many of the members had been on the board for over 20 years. The Proxy Statement concluded that Termeer was too close to the Company given his 25 years at the Company, and that the average board tenure of many of the other directors was more than 12 years.

61.Icahn further questioned how Termeer was able to earn approximately $35 million since 2007 given his performance and the massive mismanagement which had occurred at the Company under his supervision.

62.Finally, the Proxy Statement indicated that Icahn would ask the board to evaluate Termeer and current management taking into account the massive mismanagement that had occurred under their watch, and the extent of their compensation.

63.Soon after this scathing Proxy Statement, and this public airing of Termeer’s faults, Termeer reached out to Icahn in an attempt to stave off a proxy fight, and his potential ouster from the Company.

64.Concerned that Icahn would be successful in getting his slate elected at a June 16th shareholder meeting, in a partial concession to Icahn, and in an effort to keep his position and those of the other long term directors, Termeer agreed to allow Icahn to propose two nominees to the now expanded board of 13 directors, if Icahn agreed to vote his shares in support of Termeer and the current slate of directors.

65.Some commentators speculated that one of the reasons for the compromise was Termeer’s concern that Icahn would sell the Company to the highest bidder—an opportunity which would benefit shareholders, but cut against Termeer’s personal interest and that of the

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other long standing directors in maintaining their positions. See Genzyme v. Icahn: Is Carl’s Bark Worse than His Bite?, www.biojobblog.com/2010/06/articles/biocareers.

Management Refuses to Negotiate In Good Faith With Sanofi

66.Press reports indicate that on about August 2, 2010 , Sanofi offered to purchase Genzyme for $69 to $70 per share for a total price of $18.5 billion.

67.Although it may take years for Genzyme to recover from its massive mismanagement, and the slew of lawsuits it faces as a result of Termeer’s and other’s mismanagement, press reports indicate that Genzyme has continued to refuse to provide Sanofi with due diligence and that talks have stalled.

68.In fact, on August 30, 2010, Genzyme filed a Form 8-K with the SEC attaching a letter which Termeer purportedly sent to Sanofi.

69.This letter confirmed for the first time that in fact, Sanofi had made a formal offer to Genzyme for the purchase of the Company at $69 per share, and that Genzyme had twice refused to negotiate with Sanofi.

70.While the letter indicated that Genzyme’s advisors and Sanofi’s advisors had some discussions about Genzyme’s progress in addressing its mismanagement of its manufacturing facilities, the letter did not indicate that Genzyme had provided Sanofi with any material which would have enabled it to comfortably commence negotiations for a higher bid.

71.In fact, the letter indicated that Sanofi indicated that it was willing to pay more but that it did not want to bid against itself—meaning that if Genzyme would engage in full and fair negotiations, Sanofi would be willing to raise its offer.

72.Moreover, Sanofi’s chief executive officer, Christopher Viehbacher, has accused Defendants of “stonewalling” negotiations. “We are disappointed that you rejected our

14

proposal on Aug. 11 without discussing its substance with us,” Sanofi’s chief executive wrote in a letter to Genzyme’s chief executive, Henri A. Termeer, “Our financial advisers finally met briefly on Aug. 24, but the meeting simply served as further confirmation that as throughout you remain unwilling to have constructive discussions.”

73.This letter makes clear that it is Genzyme’s refusal to engage in any meaningful negotiations which is preventing Plaintiff and the Class members from obtaining maximum price for its shares.

74.Press reports further indicate that Sanofi may take steps to launch a hostile bid for the Company.

75.Further, on August 31, 2010, the Boston Globe reported that Defendant Termeer acknowledged that Genzyme could be up for sale, yet the Company still refuses to engage Sanofi or other potential bidders. See “Genzyme CEO says sale possible, at the right price,” http://www.boston.com/business/ticker/2010/08/genzyme_ceo_say.

76.At this point, given the state of Genzyme’s manufacturing facilities, that it will be under FDA supervision for years, that it has allowed competitors to encroach on some of its niche markets, and the fact that Termeer himself has considered selling significant portions of the Company, there is no reason for Genzyme to refuse to negotiate in good faith with Sanofi, or to take other steps which would prevent selling the Company for maximum value.

77.The only rationale for Genzyme’s reluctance to negotiate in good faith with Sanofi is that Termeer and other board members, consistent with their earlier conduct, continue to put their interests first in entrenching themselves rather than doing what is best for the shareholders and the Company.

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78.The Activist Directors do not have sufficient clout to ensure that Genzyme will be sold, or that Termeer is negotiating in good faith with Sanofi. They constitute only four of the 13 directors, to which Termeer expanded the board when he believed he was in jeopardy of losing his position. Moreover, to this point, they have apparently been unable to get Termeer and other members of management to enter into negotiations with Sanofi.

79.Plaintiff thus brings this action to ensure that the board, and particularly Termeer, takes all steps necessary to maximize shareholder value, including negotiating in good faith with Sanofi, and shopping the Company or entering a “go shop” period if a deal is struck with Sanofi.

80.Moreover, Plaintiff brings this action to ensure that any transaction be entirely fair to the public shareholders of Genzyme, including that any transaction provide the shareholders with a fair price, and be obtained through a fair process, untainted by Termeer’s interests and those of the other board members.

81.In their roles as directors of a corporation, the Defendants have fiduciary obligations under Massachusetts G.C.L. Ch. 156 D, Section 8.30 (2010) to: discharge their duties in (1) good faith, (2) with the care that a person in a like position would reasonably believe appropriate under similar circumstances, and (3) in a manner the director reasonably believes to be in the best interests of the company.

82.Included in those duties is the duty to take steps to maximize shareholder value when appropriate, and to engage in transactions that are entirely fair to the shareholders of the company.

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83.By failing to negotiate in good faith with Sanofi, and instead taking steps to entrench themselves, the Defendants have breached their fiduciary duties to Genzyme’s shareholders and Class members.

Count: Breach of Fiduciary Duty Against The Defendants

84.Plaintiff repeats and realleges each and every allegation as set forth above.

85.The Defendants have violated their fiduciary duties owed to Genzyme and its shareholders and have acted to put their personal interests ahead of the interests of Genzyme shareholders or acquiesced in those actions by the remaining Directors. These Defendants have failed to take adequate measures to ensure that the interests of Genzyme’s shareholders are properly protected and have embarked on a process to entrench themselves at the expense of Genzyme and its shareholders.

86.By the acts, transactions and courses of conduct alleged herein, the Defendants, individually and acting as part of a common plan, will unfairly deprive Plaintiff and other members of the Class of the value of their shareholdings, causing them irreparable damage.

87.The Defendants have and will continue to breach their duties of loyalty, candor, entire fairness, good faith and care by not taking steps to enter into a transaction with Sanofi at the best possible price, and by failing to take other steps to maximize shareholder value.

88.By reason of the foregoing acts, or failure to act, and courses of conduct, the Defendants have failed to exercise due care and diligence in the exercise of their fiduciary duties owed to Plaintiff, the Class and Genzyme.

89.Unless equitable relief is awarded, including causing the Defendants to negotiate in good faith with Sanofi or other potential bidders, preventing them from taking steps

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which would thwart a reasonable bid by Sanofi, and causing them to auction or take other steps which would result in maximum value to the shareholders and Genzyme, the Class and Genzyme will be irreparably harmed.

90.Class members have no adequate remedy at law.

Prayer for Relief

WHEREFORE, Plaintiff demands judgment and preliminary and permanent relief, including injunctive relief, in his favor and in favor of the Class, against the Defendants as follows:

A.Certifying this case as a class action, certifying Plaintiff as a class representative, and his counsel as Class counsel;

B.Declaring that the Defendants’ conduct in failing to negotiate in good faith with Sanofi, and in failing to take other steps to maximize value are breaches of the Defendants’ fiduciary duties;

C.Preliminarily and permanently enjoining the Defendants from placing their own interest ahead of those of the Class and Genzyme;

D.Preliminarily and permanently enjoining the Defendants from instituting defensive measure which would inhibit their ability to maximize shareholder value, and enable them to entrench themselves;

E.Awarding Plaintiff and the Class appropriate compensatory damages;

F.Awarding Plaintiff costs and expenses of this action, including attorneys fees and experts’ fees, and if applicable, pre-judgment interest and post-judgment interest; and

G.Awarding Plaintiff and the Class such other and further relief as the Court deems just and reasonable.

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Dated: August 31, 2010

BERMAN DEVALERIO
By:	/s/ Abigail R. Romeo
Kathleen Donovan-Maher (BBO #558947)
Patrick T. Egan (BBO #637477)
Abigail R. Romeo (BBO #657680)
One Liberty Square
Boston, MA 02109
Tel. (617) 542-8300
Fax (617) 542-1194
Lynda J. Grant
The Grant Law Firm, PLLC
521 Fifth Avenue, 17th Floor
New York, NY 10175
T/212-292-4441
F/212-292-4442
Attorneys for Plaintiff and the Class

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EX-99.(A)(12)

Exhibit (a)(12)

COMMONWEALTH OF MASSACHUSETTS

MIDDLESEX, SS.		SUPERIOR COURT DEPARTMENT
		OF THE TRIAL COURT
Louisiana Municipal Police Employees’ Retirement System, on behalf of itself and all others similarly situated,	) ) )
	)
Plaintiff,	)	C.A. No. 10-3327
v.	)
	)
HENRI A. TERMEER, DOUGLAS A. BERTHIAUME, ROBERT J. BERTOLINI, GAIL K. BOUDREAUX, STEVE BURAKOFF, ROBERT J. CARPENTER, CHARLES L. COONEY, VICTOR J. DZAU, ERIC ENDE, DENNIS M. FENTON, SENATOR CONNIE MACK III, RICHARD F. SYRON, RALPH V. WHITWORTH, AND GENZYME CORPORATION,	) ) ) ) ) ) ) ) )
Defendants.

CLASS ACTION COMPLAINT

Plaintiff Louisiana Municipal Police Employees’ Retirement System (“LAMPERS” or “Plaintiff”), on behalf of itself and all other similarly situated public shareholders of Genzyme Corporation (hereinafter “Genzyme” or the “Company”) brings the following Class Action complaint (“Complaint”) against the Company and the individual members of the board of directors of Genzyme (the “Directors,” “Director Defendants” or the “Board”, and together with Genzyme, the “Defendants”). The allegations of the Complaint are based on the personal knowledge of Plaintiff as to itself and on information and belief (including the investigation of counsel and review of publicly available information) as to all other matters:

SUMMARY OF ACTION

1.This action arises from Defendants’ steadfast refusal to even engage in negotiations with Sanofi-Aventis SA (“Sanofi”) about a possible Sanofi acquisition of Genzyme.

The Defendants’ actions are unreasonable and constitute a breach of their fiduciary duties under Massachusetts law.

2.Genzyme specializes in making complex therapies for rare illnesses that are difficult for generic drugmakers to copy.

3.The Company has grown dramatically since it was founded in 1981, with now more than 12,000 employees and 85 locations in over 40 countries and products available in nearly 100 countries. Concomitantly with this growth, the Company’s stock price has risen as well, hitting a high of $83.25 a share in August of 2008.

4.However, the Company began to experience significant manufacturing problems and product contamination, resulting in the temporary closure of at least one Genzyme plant in June 2009 and the subsequent imposition of a $175 million fine by the Food and Drug Administration (“FDA”), along with the threat of hundreds of millions of dollars of additional fines if the manufacturing and product quality issues were not promptly resolved. As a result, the Company’s sales have dropped precipitously, along with its stock price. Indeed, Genzyme’s stock fell to $47.16 in June of this year, 43% off its 2008 high.

5.Genzyme shareholders were finally presented with an opportunity to capitalize (or for some, stem their losses) on their Genzyme investment when Sanofi approached the Genzyme Board in July about possibly acquiring the Company. In early July of this year, Sanofi, France’s largest pharmaceutical company, privately proposed to the Genzyme Board an acquisition of the Company at between $67 and $70 a share, and rumors of this proposal began to be reported on July 23, 2010. Rather than an engaging in any negotiations or further discussions, the Genzyme Board simply rebuffed Sanofi, stating that the Company was not for sale.

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6.Further attempts by Sanofi to engage the Defendants proved fruitless. Sanofi publicly disclosed its all-cash $69 a share offer on August 29, 2010, but that was also rejected by Genzyme, without any counterproposal or offer to negotiate.

7.Since the market first learned of Sanofi’s interest in Genzyme on July 23, 2010, no other bidders for the Company have emerged. Additionally, while Genzyme’s stock price initially rose in response to news about the Sanofi offer (going to $71.50 on August 3, 2010), as Genzyme’s rejections and refusals to negotiate were disclosed, Genzyme’s stock has been dropping, falling to around $66 a share. According to analysts, if Genzyme succeeds in driving Sanofi away, Genzyme’s stock will likely fall to around $50 a share.

8.Defendants’ “just say no” campaign is unreasonable. Sanofi has stated that it is open to even higher bids if Genzyme will at least enter into negotiations – but Defendants have refused all Sanofi attempts to engage in discussions about a proposed deal. Moreover, it is unlikely that Sanofi will commence an attempt at a hostile takeover, as that would prevent Sanofi from engaging in any due diligence of Genzyme. As analysts have noted, Sanofi would not pursue such a “blind” approach, given the manufacturing problems plaguing Genzyme. Indeed, in a recent filing with the FDA, Genzyme estimated that it may take up to four years to resolve those problems (despite a previous estimate of only 2-3 years).

9.In short, there is no reason for Defendants to refuse to even engage in negotiations with Sanofi. There is much to gain by negotiating – a potentially lucrative buyout, but even more to lose by refusing to do – driving Sanofi away and having Genzyme’s stock price plunge precipitously.

10.In order to improperly entrench themselves, Defendants have refused all of Sanofi’s advances, refused to allow Sanofi to conduct necessary due diligence, and refused to

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even enter into negotiations with Sanofi. Under these circumstances, Defendants have breached their fiduciary duties and unreasonably deprived Genzyme’s shareholders of the opportunity to consider and vote on Sanofi’s offer. Defendants’ entrenchment is purely for the benefit of the Director Defendants (who would lose their positions at Genzyme if Sanofi’s offer were to succeed) and deprives shareholders of a valuable opportunity to maximize their value of their shares.

JURISDICTION AND VENUE

11.This Court has jurisdiction over the subject matter of this action pursuant to M.G.L. c. 212, §3 because this action is civil in nature, for money damages, and there is no reasonable likelihood that the recovery by Plaintiff will result in less than $25,000.

12.Venue is proper in this Court pursuant to M.G.L. c. 212, § 14 because this action is connected with the business of Genzyme and Genzyme has a principal place of business in Cambridge, Middlesex County, Massachusetts.

THE PARTIES

13.Plaintiff LAMPERS is a retirement system created for the purpose of providing retirement allowances and other benefits for full-time municipal police officers and employees in the state of Louisiana, secretaries to chiefs of police and employees of this retirement system. LAMPERS is a stockholder of Genzyme, has been a stockholder of Genzyme throughout the class period alleged in this Complaint and will continue to be a stockholder of Genzyme through the conclusion of this litigation.

14.Defendant Genzyme is a biotechnology company, headquartered and incorporated in Massachusetts, that is focused on rare inherited disorders, kidney disease, orthopedics, cancer, transplant and immune disease, and diagnostic testing.

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15.Defendant Henri A. Termeer (“Termeer”) has been President of Genzyme since 1983, the Company’s CEO since 1985 and the Chairman since 1988. Termeer is a member of the Risk Oversight Committee and the Strategic Planning and Capital Allocation Committee. Termeer owns approximately 1.5% of Genzyme Stock. Termeer’s overall cash compensation for 2009 was $3,779,960.

16.Defendant Douglas A. Berthiaume (“Berthiaume”) is a Genzyme Director and has been since 1988. Berthiaume is a member of the Compensation Committee and the Nominating/Governance Committee. Berthiaume owns 160,303 of Genzyme stock and was compensated a total of $444,942 in fees, stock awards and option awards for the year ending December 31, 2009 for his services as a Director.

17.Defendant Robert J. Bertolini (“Bertolini”) is a Genzyme Director and has been since 2009. Bertolini is the Chair of the Audit Committee and a member of the Risk Management and Strategic Planning and Capital Allocation Committees. Bertolini was compensated a total of $264,835 in fees, stock awards and option awards for the year ending December 31, 2009 for his services as a Director.

18.Defendant Gail K. Boudreaux (“Boudreaux”) is a Genzyme Director and has been since 2004. Boudreaux is the Chair of the Risk Oversight Committee and a member of the Audit Committee. Boudreaux owns 70,000 shares of Genzyme stock and was compensated a total of $417,442 in fees, stock awards and option awards for the year ending December 31, 2009 for her services as a Director.

19.Defendant Steven J. Burakoff (“Burakoff’) is a Genzyme Director and has been since June 2010. Burakoff is a member of the Compensation Committee and the Risk Oversight Committee. As a Director, Burakoff will receive as compensation: an annual retainer of

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$40,000, paid quarterly; $2,500 for each Board meeting attended; $1,500 for each committee meeting he attends; and for each year, or partial year that he serves, equity awards in the form of stock options to purchase 7,125 shares of stock and restricted stock units (“RSU”) for 2,375 shares of stock, each of which will vest at the 2011 annual meeting.

20.Defendant Robert J. Carpenter (“Carpenter”) is a Genzyme Director and has been since 1994. Carpenter serves as Genzyme’s independent lead director and is a member of the Compensation and Strategic Planning and Capital Allocation Committees. Carpenter owns 113,330 shares of Genzyme stock and was compensated a total of $415,942 in fees, stock awards and option awards for the year ending December 31, 2009 for his services as a Director.

21.Defendant Charles L. Cooney (“Cooney”) is a Genzyme Director and has been since 1983. Cooeny is the Chair of the Compensation Committee and a member of the Nominating/Governance Committee. Cooney owns 66,891 shares of Genzyme stock and was compensated a total of $424,442 in fees, stock awards and option awards for the year ending December 31, 2009 for his services as a Director.

22.Defendant Victor J. Dzau (“Dzau”) is a Genzyme Director and has been since 2000. Dzau is a member of the Compensation and Risk Oversight Committees. Dzau owns 75,137 shares of Genzyme stock and was compensated a total of $412,942 in fees, stock awards and option awards for the year ending December 31, 2009 for his services as a Director.

23.Defendant Eric J. Ende (“Ende”) is a Genzyme Director and has been since June 2010. Ende is a member of the Audit Committee and the Risk Oversight Committee. As a Director, Ende will receive as compensation: an annual retainer of $40,000, paid quarterly; $2,500 for each Board meeting attended; $1,500 for each committee meeting he attends; and for each year, or partial year that he serves, equity awards in the form of stock options to purchase

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7,125 shares of stock and RSUs for 2,375 shares of stock, each of which will vest at the 2011 annual meeting.

24.Defendant Dennis M. Fenton (“Fenton”) is a Genzyme Director and has been since June 2010. Fenton is a member of the Audit Committee and the Risk Oversight Committee. As a Director, Fenton will receive as compensation: an annual retainer of $40,000, paid quarterly; $2,500 for each Board meeting attended; $1,500 for each committee meeting he attends; and for each year, or partial year that he serves, equity awards in the form of stock options to purchase 7,125 shares of stock and RSUs for 2,375 shares of stock, each of which will vest at the 2011 annual meeting.

25.Defendant Connie Mack III (“Mack”) is a Genzyme Director and has been since 2001. Mack is the Chair of the Nominating/Governance Committee and a member of the Audit Committee. Mack owns 78,687 shares of Genzyme stock and was compensated a total of $421,942 in fees, stock awards and option awards for the year ending December 31, 2009 for his services as a Director.

26.Defendant Richard F. Syron (“Syron”) is a Genzyme Director and has been since 2006. Syron is a member of the Audit and Nominating/Governance Committees. Syron owns 55,011 shares of Genzyme stock and was compensated a total of $417,442 in fees, stock awards and option awards for the year ending December 31, 2009 for his services as a Director.

27.Defendant Ralph V. Whitworth (“Whitworth”) is a Genzyme Director and has been since April 2010 and owns 10,622,708 shares of Genzyme stock (4% of the Company’s outstanding shares). Whitworth is the Chair of the Strategic Planning and Capital Allocation Committee of the Board. Whitworth receives: 1) an annual retainer of $40,000, paid quarterly; (2) a cash payment of $2,500 for each Board meeting and $1,500 for each committee meeting

7

attended; (3) an annual retainer for serving as a committee chair to be set somewhere between $10,000 and $20,000; and (4) an annual grant of stock options to purchase 7,125 shares of Genzyme’s common stock and RSUs for 2,375 shares of Genzyme’s common stock, which are granted on the date of the annual shareholders meeting and vest on the date of the next annual shareholders meeting. Whitworth will receive a pro-rated annual retainer for 2010 and, under Genzyme’s 2007 Director Equity Incentive Plan, has been granted stock options to purchase 7,125 shares of Genzyme’s common stock and RSUs for 2,375 shares of Genzyme’s common stock effective April 14, 2010, which will vest at the 2010 annual meeting of shareholders.

28.Defendants Termeer, Berthiaume, Bertolini, Boudreaux, Burakoff, Carpenter, Cooney, Dzau, Ende, Fenton, Mack, Syron, and Whitworth collectively constitute the entirety of the Company’s Board. These individuals are hereinafter referred to collectively as the “Directors” or the “Director Defendants.”

29.By virtue of their positions as Directors and/or officers of Genzyme and/or their exercise of control and ownership over the business and corporate affairs of the Company, the Director Defendants have, and at all relevant times had, the power to control and influence and did control and influence and cause the Company to engage in the practices complained of herein.

30.Each Director Defendant herein is sued individually and as an aider and abettor and in his/her capacity as a Director of Genzyme. The liability of each of the Defendants arises from the fact that they have engaged in all or part of the unlawful acts, plans, schemes, or transactions complained of herein.

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THE DIRECTOR DEFENDANTS’ FIDUCIARY DUTIES

31.Pursuant to the M.G.L. 156D §8.30, a director is required to discharge his duties as a director: 1) in good faith; 2) with the care that a person in a like position would reasonably believe appropriate under similar circumstances; and 3) in a manner the director reasonably believes to be in the best interests of the corporation.

32.Each Director Defendant owed and owes the Genzyme shareholders fiduciary obligations of due care, good faith, and loyalty and were and are required to: (1) use their ability to control and manage Genzyme in a fair, just, and equitable manner; (2) act in furtherance of the best interests of the Genzyme shareholders; (3) act to maximize shareholder value in connection with any change in ownership and control to the extent consistent with governing statutes; (4) govern Genzyme in such a manner as to heed the expressed views of its public shareholders; (5) refrain from abusing their positions of control; and (6) not favor their own interests at the expense of the Company’s public shareholders.

33.The Director Defendants, separately and together, as they continue to refuse to negotiate with Sanofi, are knowingly or recklessly violating their fiduciary duties of good faith and care owed to the Class.

FACTUAL BACKGROUND

A.Genzyme Experiences Several Manufacturing Crises and Other Woes

34.Founded in 1981, Genzyme has grown from a small start-up to a diversified enterprise with more than 12,000 employees. A leading biotech company with products and services focusing on rare inherited disorders, kidney disease, orthopaedics, cancer, transplant and immune disease, and diagnostic testing, Genzyme has a substantial development program focusing on various areas of unmet medical need.

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35.Today Genzyme has more than 85 locations in over 40 countries, including 17 manufacturing facilities, and the Company’s products are available in nearly 100 countries.

36.In the fall of 2008, the Company’s stock hit its peak at $83.25 a share. In the following months, the Company began to experience one manufacturing disaster after another – causing disruption in its production of key Genzyme drugs, a resulting decrease in the Company’s total sales, and a plunge in the Company’s stock price. Despite the Defendants’ attempts to fix the Company’s manufacturing problems and resume full shipment of the effected drugs, the Company’s stock price has not reached its 2008 peak.

37.The problems began in June 2009, when Genzyme’s Allston, Massachusetts plant was forced to shut down completely after a virus was discovered in one of the bioreactors. Genzyme’s forced shut down has caused massive production shortages of its two best selling drugs, Cerezyme and Fabrazyme. Each drug, which can cost $250,000 or more a year, is prescribed to treat rare diseases in patients who lack enzymes needed for critical bodily functions. Last year Cerezyme, a treatment for Gaucher (a genetic condition that causes lipids, a fatty substance, to accumulate in cells and certain organs), generated almost $795 million in sales. Fabrazyme, designed to treat Fabry disease (a condition that causes glycolipids to accumulate within the blood vessels, other tissues and organs) had just under $430 million in 2009.

38.As a result of the contamination and subsequent forced shut down, supplies of Cerezyme and Fabrazyme are heavily depleted and remain insufficient to meet patient demand still today, more than a year later. The manufacturing problems have caused the Company to “ration” the drug treatments, forcing patients to adopt a treatment plan using only half the normal dose, and in some cases only 20-30 percent of the normal dose.

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39.The drug shortages have resulted in hundreds of millions of dollars in lost sales, prompting Genzyme to forecast a drop in its annual revenue, estimating 2010 annual revenue to be $4.4 billion, down from $4.5 billion in 2009.

40.As a result of the June 2009 contamination of the Allston plant, the FDA hit Genzyme with a whopping $175 million fine, stating that the Company had violated stringent manufacturing rules and compromised patients’ safety. The Company was forced to sign a consent decree to correct the manufacturing and product quality violations.

41.Pursuant to the consent decree, Genzyme will now have to retain a third party consultant, Quantic, to both assist it in submitting a remediation plan to the FDA and to oversee the implementation of the plan itself. The decree contemplates a remediation plan that will take two to three years to complete, with milestones staggered throughout this period. For each milestone Genzyme misses, the FDA can require Genzyme to pay $15,000 per day per affected drug until the remediation milestone has been satisfied. Genzyme has until the end of the year to submit its manufacturing remediation plan to the FDA.

42.The decree also requires the Company to transfer its operations for filling drug vials from Allston to other facilities. Indeed, some of the Allston operations have been moved out of the United States to the Company’s facility in Waterford, Ireland, and the Company executed a separate agreement with Hospira Worldwide Inc. for that company to provide bottle filling and finishing services for certain Genzyme medicines. If Genzyme fails to meet FDA deadlines for moving these and other services to other facilities, the Company may face an additional $130 million in fines.

43.The Company has already had to extend the remediation timeline envisioned in the FDA consent decree. While the initial timeline for complete remediation agreed to by the

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FDA and Genzyme was two to three years, the Company now states that the manufacturing issues will take three to four years to correct.

44.Manufacturing and product quality issues are not confined to Genzyme’s Allston plant. In July, 2010, Genzyme was forced to discard large amounts of Cerezyme and Fabrazyme because of a disrupted water supply at a Boston factory. This caused the Company to take a $21.9 million write-off in its second quarter 2010 results.

45.Additionally, on August 9, 2010, Genzyme announced that it was experiencing more manufacturing problems. The Company stated in a regulatory filing that it was taking another second quarter write-off, this one for $6.5 million, for medicines that had failed to meet quality standards, resulting in a loss for the period. On August 10, 2010, the Company identified the same drugs that were at issue in the June 2009 Allston plant shut-down – Cerezyme and Fabrazyme – along with additional drugs – thyroid medicine Thyrogen and its Cholestagel cholesterol fighter.

46.In a further setback for Genzyme, patients, frustrated with drug shortages, have begun to challenge Genzyme’s exclusive licenses to certain drugs. According to Bloomberg, a group of patients with Fabry disease have asked the Department of Health and Human Services (“HHS”) to break Genzyme’s exclusive license to the patent for Fabrazyme. The petition was submitted on August 2, 2010 and asks that the Fabrazyme patents be opened up so that “responsible entities” can use the technology to make and sell the drug, which has been rationed since the June 2009 Allston plant contamination. See Bloomberg, Medicines, Fresenius, Genzyme, Boeing, Google, Puma: Intellectual Property, August 5, 2010. The patient group’s representative, C. Allen Black Jr., has said, “[i]f we are able to interest manufacturers, we can

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end or lessen the shortage,” and in the event that the Company runs into trouble again “there is still a drug source for patients.” See id.

B.Sanofi’s Initial Offer And Defendants’ Failure To Negotiate

47.Sanofi is France’s largest drugmaker and fourth biggest company by market value. It is based in Paris, France. A leading global pharmaceutical company, Sanofi operates in over 100 countries to advance healthcare around the world.

48.On July 23, 2010, The New York Times published an article titled “Sanofi Said to Have Offered to Make a Bid for Genzyme,” disclosing Sanofi’s initial approach to Genzyme. The article stated:

Sanofi-Aventis has made an informal takeover approach to Genzyme, a person brief on the matter said on Friday, as the French drug maker seeks to bolster its biotechnology offerings.

Genzyme would bring Sanofi an attractive portfolio of drugs that treat rare conditions like Fabry disease. Because of their relative complexity, Genzyme’s products fetch high prices. Cerezyme, a treatment for Gaucher’s disease and one of the company’s main products, has garnered more than $1 billion in annual sales, though it is used to treat fewer than 6,000 patients.

49.While the initial communication between Sanofi and Genzyme was not publicly disclosed, a combination of those companies makes business sense. Indeed, as would be reported later, analysts believed that a Sanofi-Genzyme merger would result in a strategic advantage because:

Sanofi faces generic competition on the bulk of its best-selling drugs by 2012, at a speed unparalleled among large European pharmaceutical peers. A generic version of its best seller Lovenox received U.S. approval last month. Acquiring Genzyme would give Sanofi a new pipeline of highly profitable treatments for rare diseases.

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Half of Sanofi’s new-development portfolio is in biological treatments such as vaccines, but it lacks expertise in Genzyme’s specialist biotech field.

See The Wall Street Journal, “Sanofi’s Genzyme Health Warning,” August 3, 2010.

50.On July 29, 2010, there were reports that Sanofi’s board had authorized its executives to formally offer up to $70 per share or $18.7 billion for Genzyme. On or around that same date, Sanofi sent a letter to Genzyme’s board outlining a potential takeover. The letter proposed paying $67 to $70 a share. See The New York Times, “Drug Giants Said to Talk of Merger,” August 2, 2010.

51.On August 3, 2010, according to the Wall Street Journal, Sanofi presented Genzyme with an offer of $69 a share, representing a 31% premium over Genzyme’s average share price in the twenty days leading up to July 22 – the day before reports began to circulate that Sanofi was interested in acquiring Genzyme.

52.Almost immediately, there were reports that the Genzyme Board did not even consider entering into negotiations or any discussions at all with Sanofi, despite the strategic advantages in a combination of those companies.

53.On August 11, 2010, without any public release or announcement to the shareholders (but which news would later be publicly reported), Defendants summarily rejected Sanofi’s proposal.

54.Despite this rejection, Sanofi continued to attempt friendly negotiations with Defendants. Sanofi’s attempts continued for about a month, until late August. Finally, after repeated requests, Defendant Termeer allowed financial advisors from the two companies to meet on August 24, 2010, although that meeting had a “limited scope.” However, the Director Defendants did not engage in any negotiations with Sanofi, or allow Sanofi or its advisors access

14

to any Genzyme materials or facilities. Sanofi requested, but Genzyme rejected, the opportunity to conduct due diligence. As Sanofi CEO, Chris Viehbacher (“Viehbacher”) stated, “the meeting simply served as further confirmation that as throughout you remain unwilling to have constructive discussion.” See The Wall Street Journal, “Sanofi Unveils Genzyrne ‘Bear Hug’”, August 29, 2010.

55.On August 29, 2010, Viehbacher publicly disclosed Sanofi’s bid. According to an article in The Wall Street Journal, Viehbacher sent the Genzyme Board a “bear hug” letter offering an $18.5 billion all cash bid for Genzyme at $69 per share. Id. In the letter, Viehbacher described Sanofi’s frustrations at Defendant Termeer’s unwillingness to engage in discussions, and Sanofi’s disappointment that the proposal was rejected on August 11 without any substantive discussions. See id. Sanofi expressed the hope that the offer would bring the “resistant” Genzyme Board to the table.

56.Sanofi made it clear to Defendant Termeer and Genzyme’s Board that Sanofi is “prepared to consider all alternatives to successfully complete this transaction. Id. Viehbacher indicated that Sanofi is open to negotiating on price, saying “we are reasonable people,” and he looked forward to the opportunity to “sit down with the board of directors and have the opportunity to present each other’s views.” Id.

57.According to Bloomberg, Viehbacher has “left the door open to a higher bid.” See Bloomberg, “Sanofi May Need to Pay $77 a Share for Genzyme,” August 31, 2010. However, Viehbacher’s counterpart at Genzyme, Termeer, has refused to even commence negotiations. In his letter of August 30, 2010, Termeer stated:

On August 11, 2010, Genzyme responsded to your first letter dated July 29, 2010. In our response, we stated that, “without exception, each member of the Genzyme board believes this is not the right time to sell the company, because your opportunistic takeover

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proposal does not begin to recognize the significant progress underway to rectify our manufacturing challenges or the potential for our new-product pipeline.” Our board met last evening in response to your second letter and unanimously confirmed those views.

* * *

You and your advisors claim you are willing to pay more but that you are unwilling to “bid against yourself.” The Genzyme board is not prepared to engage in merger negotiations with Sanofi based upon an opportunistic proposal with an unrealistic starting price that dramatically undervalues our company.

See Business Wire, “Genzyme Confirms Receipt of Unsolicited Proposal,” August 30, 2010. While Viehbacher has stated that his priority is to sit down with Genzyme’s management and “discuss what the options are,” the Defendants have made this impossible.

58.In fact, Defendants have not even allowed Sanofi to commence due diligence to determine whether there is more value to Genzyme to justify a higher bid. As analyst Jeff Holford at Jefferies International stated in an August 10, 2010 interview, this due diligence is critical, particularly for biotechnology companies such as Genzyme experiencing manufacturing setbacks, which make those companies “risky” targets and “good examples of why companies should not pay any price to get those assets.” He cited Novartis AG’s 2006 acquisition of Chiron Corp., where manufacturing glitches took years to resolve.

59.Similarly, Michael Leuchten, senior research analyst and senior scientist at Barclays Capital stated in a research report “[t]he company [Sanofi] needs access to the books, manufacturing plants and correspondence with the FDA to do the appropriate due diligence.” However, as Viehbacher aptly summarized, Sanofi had “essentially encountered a brick wall.” See id.

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60.The Defendants’ “just say no” campaign is designed only, and will have no effect but to, drive Sanofi away. Indeed, Sanofi has already stated that it will not “bid against itself.”

61.Additionally, Genzyme is not the only game in town. Analysts have reported that Sanofi may consider other targets, including Bausch & Lomb Inc., Allergen, Inc. and Celgene Corp., should a deal with Genzyme fail. Indeed, as reported by Bloomberg on August 25, 2010, in an article entitled “Sanofi Said Unwilling to Raise Genzyme Bid, Weighing Options,” Sanofi has “said it plans to expand in the eye-care business.”

62.The unreasonableness of Defendants’ actions is further evidenced by the failure of any other bidders to emerge. As Marc Booty, investment manager at Pictet Asset Management Ltd. said in an August 9, 2010 interview with Bloomberg, “[w]ithout a competing bid what’s there to drive the price up?”

63.If forced to choose between walking away and mounting a hostile takeover attempt, Sanofi would likely walk. As analysts have explained, a hostile takeover bid by Sanofi “wouldn’t allow a full review of manufacturing changes made after a plant contamination caused drug shortages.” See M. Tirrcll and Trista Kelley, “Sanofi Hostile Genzyme Bid Deemed Unlikely,” September 1, 2010, Telegram. Michael Leuchten, an analyst with Barclays Capital in London said, “[a] potential deal is only possible after Sanofi has the opportunity for full due diligence.” Id. Michael Yee, an analyst with RBC Capital Markets, similarly stated: “[a]ny potential bidder would want to see how well Genzyme resolved production glitches.” Id.

64.With the Genzyme Board freezing Sanofi out of due diligence and not engaging Viehbacher and Sanofi in any negotiations, Sanofi is deprived of the information and opportunity to increase its bid. As reported on August 31, 2010 by Bloomberg, Sanofi “indicated it may raise its $69-a-share cash bid if Genzyme’s management would come to the negotiating table.”

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However, Defendants have stubbornly refused to come to the table, thereby unreasonably depriving Genzyme’s shareholders of the opportunity to consider and vote on Sanofi’s offer.

65.Absent a deal with Sanofi, Genzyme’s share price is sure to plummet. While Genzyme’s share price climbed from $49.86 on July 22, 2010 (just prior to rumors that Sanofi was interested in Genzyme) to $71.50 on August 3, 2010 on continuing disclosures regarding Sanofi’s offer, as the market grew concerned that the deal might not happen, due to Defendants’ intransigence, Genzyme’s stock has fallen, eventually trading down to around $66 a share.

66.Without another bidder in play and with Sanofi unlikely to go hostile, the shareholders will be the ones left holding the bag. As one analyst noted: “[n]o one wants to be the one holding Genzyme stock when it was down near $50, reaches near $70 and then goes down to $50 again, which would happen if Sanofi walked away.” See Bloomberg Businessweek, “Sanofi, Genzyme in ‘Game of Chicken’ as No Rivals Bid,” August 12, 2010. Citigroup analysts have said that were Sanofi to walk away, “Genzyme’s share would likely fall to between $50 and $55,” which is about where the stock was trading in the month leading up to the first disclosure of Sanofi’s interest. See Bloomberg, “Sanofi May Need to Pay $77 a Share for Genzyme,” August 31, 2010.

67.In short, there is no reason for Defendants to simply rebuff Sanofi without any counterproposal or offer to engage in negotiations. Defendants’ actions are unreasonable and transparently designed to entrench themselves in their positions and drive Sanofi away. Under these circumstances, Defendants’ actions are in violation of Massachusetts law and constitute a breach of their fiduciary duties.

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CLASS ACTION ALLEGATIONS

68.Plaintiff brings this action pursuant to Rule 23 of the Massachusetts Rules of Civil Procedure on behalf of itself and all other holders of Genzyme common stock (other than Defendants and any persons or entities related to or affiliated with Defendants and/or their successors-in-interest) who have been harmed and/or are threatened with harm as a result of Defendants’ wrongful conduct alleged herein (the “Class”).

69.This action is properly maintainable as a class action.

70.The Class is so numerous that joinder of all members is impracticable. As of August 30, 2010, there were 266 million shares of Genzyme common stock outstanding, which were held by individuals and entities too numerous to bring separate actions. At all relevant times, the beneficial holders of Genzyme stock have been geographically dispersed throughout the United States and internationally.

71.There are questions of law and fact that are common to the Class and that predominate over any issues affecting only individual Class members, including, among others:

(a)whether Defendants have fulfilled or instead have breached their fiduciary duties of due care, good faith, and loyalty to Plaintiff and the other members of the Class;

(b)whether Plaintiff and the other members of the Class have been harmed by Defendants’ alleged failure to fulfill their fiduciary duties of due care, good faith, and loyalty; and

(c)whether Defendants’ refusal not to engage in negotiations with Sanofi or afford the shareholders of Genzyme the opportunity to vote on Sanofi’s offer are reasonable or instead unreasonable responses to any perceived threat.

72.Plaintiff is committed to prosecuting this action and has retained competent counsel experienced in litigation of this nature. Plaintiff’s claims are typical of the claims of the

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other members of the Class. Accordingly, Plaintiff is an adequate representative of the Class and will fairly and adequately protect the interests of the Class.

73.The prosecution of separate actions by individual members of the Class would create a risk of (a) inconsistent or varying adjudications with respect to individual members of the Class which would establish incompatible standards of conduct for Defendants, or (b) adjudications with respect to individual members of the Class which would as a practical matter be dispositive of the interests of the other members not parties to the adjudications or substantially impair or impede their ability to protect their interests.

74.Defendants have acted or refused to act on grounds generally applicable to the Class with respect to the matters complained of herein, thereby making appropriate the relief sought herein with respect to the Class as a whole.

75.A class action is superior to other available methods for the fair and efficient adjudication of this controversy. The expense and burden of individual litigation make it impracticable for Class members individually to seek redress for the wrongful conduct alleged herein. Plaintiff anticipates that there will be no difficulty in the management of this litigation as a class action.

COUNT I

(Class Claim For Breach of Fiduciary Duty Against All Defendants)

76.Plaintiff repeats and realleges each and every allegation above as if set forth in full herein.

77.The Defendants owe Plaintiff and the Class the utmost fiduciary duties of due care and loyalty, including the obligation to act in good faith. The Defendants have failed to

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fulfill their fiduciary duties by rejecting all offers and approaches by Sanofi and refusing to engage in any negotiations with Sanofi.

78.Rather than engage in discussions with Sanofi, Defendants, in violation of Massachusetts law and in breach of their fiduciary duties, improperly adopted a “just say no” policy that was an unreasonable and disproportionate response to Sanofi’s proposal and a violation of the fundamental rights of Plaintiff and the Class.

79.Defendants’ breaches of their fiduciary duties have and are continuing to cause harm to Plaintiff and the Class by, inter alia, foreclosing opportunity to maximize shareholder value through an acquisition by Sanofi and preventing the shareholders from the opportunity to vote on that transaction, thus impacting shareholder franchise.

80.Plaintiff and the Class have no adequate remedy at law.

PRAYER FOR RELIEF

WHEREFORE, Plaintiff prays for judgment in favor of itself and the Class and against Defendants, as follows:

(a)declaring that this action is properly maintainable as a class action;

(b)declaring that the Defendants have breached their fiduciary duties to Plaintiff and the Class by refusing to negotiate with Sanofi;

(c)awarding Plaintiff and the Class compensatory damages, together with pre- and post-judgment interest;

(d)awarding Plaintiff the costs of pursuing this action, including, but not limited to, Plaintiff’s attorneys’ fees and expenses and experts’ fees; and

(e)awarding such other and further relief as the Court deems just and proper.

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	By its attorneys,
	/s/ Joel Z. Eigerman
	Joel Z. Eigerman BBO #152000 60 Reservoir Street Cambridge, MA 02138 (617) 945-1068
	GRANT & EISENHOFER, P.A.
	BY:	/s/ John C. Kairis/jze
		Jay W. Eisenhofer
		John C. Kairis
		Cynthia A. Calder
		1201 North Market Street, Suite 2100
		Wilmington, DE 19801
		Telephone: (302) 622-7000
September 2, 2010

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EX-99.(E)(1)

Exhibit (e)(1)

Excerpt from Genzyme Corporation’s Definitive Proxy Statement on Schedule 14A related to the 2010 Annual Meeting of Shareholders as filed with the Securities and Exchange Commission on April 26, 2010.

DIRECTOR COMPENSATION

for the year ended December 31, 2008

Name	Fees Earned or Paid in Cash ($)	Stock Awards (1)(2)	Option Awards ($)(1)(2)	All Other Compensation ($)	Total ($)
Douglas A. Berthiaume	98,500	104,596	262,865	—	465,961
Gail K. Boudreaux	70,000	104,596	262,865	—	437,461
Robert J. Carpenter	69,500	104,596	262,865	—	436,961
Charles L. Cooney	79,500	104,596	262,865	—	446,961
Victor J. Dzau	69,500	104,596	262,865	—	436,961
Sen. Connie Mack	77,000	104,596	262,865	—	444,461
Richard F. Syron	67,500	104,596	262,865	—	434,961

(1)The amounts reported for stock and option awards represent the expense recognized in our financial statements for 2008 in accordance with Financial Accounting Standards No. 123R (“FAS 123R”), excluding an estimate for forfeitures related to service-based vesting conditions. Compensation expense for RSUs is based on the grant date fair market value of the award and is recognized over the service period, which generally represents the vesting period. On May 22, 2008, under the automatic grant provisions of our 2007 Director Equity Plan, each non-employee director was granted RSUs for 2,500 shares, and stock options to purchase 7,500 shares, of our stock. The RSUs have a grant date fair value of $171,200, or $68.48 per share. The 2008 expense was $104,596 for each award. The stock options have an exercise price of $68.48 per share, which was the closing price of our stock on that date. Each option grant has an aggregate grant date fair value of $184,031, or $24.54 per share, computed in accordance with FAS 123R and based on the Black-Scholes option pricing model. The 2008 expense was $112,435 for each stock option granted in 2008 plus 2008 vesting for stock options granted in 2007.

For a discussion of the relevant assumptions we use to calculate grant date fair value, see the sections “Accounting for Stock-Based Compensation” in “Note A. Summary of Significant Accounting Policies” and “Note M. Stockholders’ Equity” of the “Notes to Consolidated Financial Statements” in our 2008 Annual Report on Form 10-K.

(2)Non-employee directors had the following aggregate stock options and RSUs outstanding as of December 31, 2008:

	Stock Options	RSUs
Douglas A. Berthiaume	87,836	2,500
Gail K. Boudreaux	67,500	2,500
Robert J. Carpenter	126,687	2,500
Charles L. Cooney	58,235	2,500
Victor J. Dzau	70,087	2,500
Sen. Connie Mack	76,187	2,500
Richard F. Syron	52,500	2,500

The outstanding stock options have an average exercise price of $55.51 per share and a remaining average life of 6.2 years.

Henri Termeer, our only employee director, does not receive any additional compensation for his service on the board of directors. The other seven directors, who are not employees, receive the following cash compensation for their service on the board and its committees:

·an annual retainer of $40,000, paid quarterly;

·$2,500 for each board meeting they attend;

·$1,500 for each committee meeting they attend;

·an annual retainer of $20,000 for service as audit committee chair, paid quarterly;

·an annual retainer of $10,000 for service as compensation committee chair, paid quarterly; and

·an annual retainer of $10,000 for service as nominating and corporate governance committee chair, paid quarterly.

Non-employee directors also receive equity awards for each year (or partial year) that they serve on our board. Stock options and RSUs are granted automatically under our 2007 Director Equity Plan on the date of each annual meeting of shareholders or, in the case of directors elected other than at an annual meeting, upon election to the board. The plan provides for an annual grant to each non-employee board member of (1) stock options to purchase 7,500 shares of our stock, and (2) RSUs for 2,500 shares of our stock. Stock options and RSUs become fully vested on the date of the next annual shareholders meeting following the date of grant, provided the director is an active member of the board at the opening of business on that date. Each stock option grant has an exercise price equal to the closing price of the stock on the date of grant and a term of ten years. RSUs are valued on the date of grant based on the closing price of our stock. The plan provides for acceleration of all unvested awards in the event of a change in control of the company.

Under our Directors Deferred Compensation Plan, each director may choose to defer receipt of all or part of the cash compensation payable to him or her as a director until the year following the year his or her service as a director ends or until another date specified in advance by the director. The director can elect to defer compensation in exchange for a future payment of cash, stock or a combination of cash and stock. At the director’s election, the future payments may be made in either a lump sum or annual installments for a period specified by the director, up to a maximum of five years. Amounts deferred in the cash account are credited with interest on the last day of each calendar quarter at the rate paid on 90-day Treasury bills hypothetically purchased on the first day of the calendar quarter. Amounts deferred in the stock account are treated as invested in hypothetical shares of our common stock, and the hypothetical shares are credited to the director’s account on the first day of each calendar quarter based on the average closing price of our common stock for all trading days during the preceding quarter. As of December 31, 2008, five of the seven eligible directors had accounts under the plan.

COMPENSATION DISCUSSION AND ANALYSIS

In considering our executive compensation policies and practices, we have an obligation to balance our interest in conserving cash and minimizing shareholder dilution, with our interest in using compensation to attract, retain and motivate employees who contribute to the company’s success. In reconciling these competing concerns, we strive to act in the long-term best interests of the company and our shareholders. The board of directors has chartered the compensation committee to discharge the responsibilities of the board to establish executive compensation policies and oversee executive compensation practices. The compensation committee may consult with compensation consultants, academics and other experts to support the board’s commitment to be knowledgeable and current regarding executive compensation trends and best practices. The committee has hosted, and plans in the future to host, special meetings with the full board to educate board members on key issues in the business environment and the role those issues play in executive compensation. These meetings include a review of our compensation philosophy as it applies to equity and cash, as well as accounting and disclosure requirements.

Objectives and Overview of Executive Compensation.  Our objective is to make executive compensation decisions that are thoughtful, transparent and consistent with the overall goals of the organization.

·Our executive compensation philosophy is built on a platform of simplicity and alignment with shareholder interests. We pay our executives using three components: base salary, annual incentive cash awards and long-term equity awards. We have avoided other long-term obligations such as defined benefit programs, supplemental employee retirement plans, nonqualified deferred compensation plans and retiree health benefits.

·Our perspective is long-term. Our compensation program reflects the nature of the long product development business cycle in the healthcare industry. This approach attempts to align our compensation decisions with shareholders’ interests in our achievement of sustainable business objectives and corporate performance goals. We operate in a complex, dynamic environment and it often takes years to achieve our goals. For example, moving a therapeutic product from concept to market can take in excess of eight years, and many products never make it to market. Acquisitions, of products, companies or intellectual property rights, are opportunistic in nature. Building an infrastructure to accommodate future products and growth requires early investment with

no guarantee of return. This perspective requires us to properly prepare for the future to continue to drive our growth and success.

·We also maintain a philosophy of inclusiveness by providing a broad-based equity program to motivate our employees to become stakeholders and invest in achieving success for the company. Motivating our employees to achieve business goals and milestones aligns their interests with our shareholders’ interests.

Process and Philosophy for Setting Executive Compensation.  We look to our named executive officer group to focus on building and creating the future of the company and expect them to make strategic decisions that continue to move the company successfully forward. We apply deliberate, thoughtful processes throughout the year to discuss and correlate executive compensation levels with performance. The committee reviews and sets cash compensation for all of our executives for the coming year in December. In February, the committee reviews the prior year’s overall performance to determine whether and at what level to award cash incentive compensation for the previous year. In May, the committee determines whether to award equity compensation and, if awarded, the amount and mix of such awards. Therefore, throughout the year there is a continuing assessment of corporate and individual executive performance that guides the committee in making compensation decisions. By making compensation decisions considering both competitive market practice and our unique organization and culture, we strive to achieve a balance between creating an appropriate compensation program for our executives while recognizing shareholder interests in limiting company expenditures.

Our expectations for our chief executive officer and other executive officers are focused on a sustainable business strategy that includes:

·financial performance;

·company growth through both acquisitions and internal product development;

·strategic management of the complexities of a global business with a diverse and growing product portfolio and expanding the business into a greater number of new markets; and

·operational business management, including development of a diverse and complex global manufacturing infrastructure, investment in strong science and research capabilities, integration of acquisitions, and development of a strong executive management team.

The compensation committee establishes annual cash incentive targets for our named executive officers based on an individual component and a corporate component. The corporate component is based on the achievement of the operating income goal set by the board of directors in connection with approving our annual budget. The committee believes the operating income goal is set at a realistic, but not easily achievable level, which should focus our executive team on meeting our short-term financial goals. Certain factors present challenges to our executive team that must be met in order to achieve short-term results that are sustainable over the long-term, including:

·international pricing pressures for our products;

·multiple and complex regulatory pathways;

·containment of expenditures while continuing to grow our businesses and develop new products;

·managing the uncertainties of fluctuations in foreign currency exchange; and

·managing resources for multiple function projects, such as late-stage R&D and capital projects.

The corporate component of the annual cash incentive is payable based on a formula that allows for 100% payment when 100% of the operating income goal is met. If the operating income goal is exceeded, for every 1% above the goal, 2.5% is added to the annual cash incentive payment up to a maximum of 150% payment for achievement of 120% or more of the goal. If the operating income goal is not met, for every 1% below the goal, 1.5% is deducted from the annual cash incentive payment. No corporate annual cash incentive is paid if less than 86% of the operating income goal is met. The individual component of the bonus is paid at the discretion of the committee.

Peer Group and Market Analysis.  The compensation committee analyzes the compensation practices of peer companies from the biotechnology industry sector for comparison purposes and to gain an external perspective in preparation for setting executive salaries and short- and long-term incentive compensation. The committee regularly reviews this industry group as well as companies in other business sectors and the peer companies disclosed by our peer companies to ensure that the committee is considering executive compensation levels against appropriately comparable companies. Towers Perrin prepares an analysis using our industry-based list to identify specific financial characteristics of each company to consider for our peer group, which include:

·revenue size and growth rate;

·research and development expense;

·number of employees;

·market capitalization;

·one- and three-year total shareholder return;

·net income;

·similarity of core businesses to ours; and

·international presence.

Following the compensation committee’s analysis and discussions with Towers Perrin and select senior management personnel, the committee decides which companies make up our peer group. Our current peer group includes: Allergan, Inc., Amgen Inc., Biogen Idec Inc., Celgene Corp., Cephalon, Inc., Genentech, Inc. and Gilead Sciences, Inc. While we recognize that the number of peer companies we reference for compensation purposes is limited, we believe that these organizations best reflect the selection criteria outlined above. The committee looks at the data from this peer group on a holistic and individual basis when considering appropriate pay positioning.

In addition to peer group analysis, each year the compensation committee considers nationally recognized, published survey data for market comparisons for select executive positions. For 2008, the committee reviewed survey data from four published survey sources:

·the 2007 Towers Perrin Executive Compensation Database;

·the 2007 Towers Perrin Pharmaceutical Executive Compensation Database;

·the 2007 Radford Global Life Sciences Compensation Survey; and

·Watson Wyatt’s 9th Annual Survey of Long Term Incentives.

These surveys help the committee to match our incumbent executives to appropriate survey positions, when data is available, by looking at scope of responsibilities for various positions as well as internal comparisons. Specifically, for each executive officer position, the committee reviews competitive levels of base salary, annual incentive awards and equity incentive grants to supplement the data gathered from the proxy filings of our peer companies listed above.

Equity.  We structure our equity compensation program to correlate with the performance of the company over time. Our shareholders expect us to create value, and that value is ultimately reflected in our stock price. Our equity compensation program is designed to address shareholder interests by providing our employees appropriate long-term incentives to motivate and retain them in a future-oriented, research and development-based environment such as ours. To utilize equity compensation responsibly and maintain competitiveness, the compensation committee establishes guidelines to limit the total number of equity awards that may be granted in a fiscal year to a stated percentage of shares outstanding. The objective of this philosophy is to manage the potential dilutive impact of the program to shareholders while continuing to provide broad-based equity awards. Each year we evaluate and adapt our program to address the challenges of an increasing employee population and the limited availability of equity reserves. We utilize a combination of stock option grants and

restricted stock unit (RSU) awards. This approach helps manage dilution and allows us to deliver an equity component of total compensation that both continues to hold value and rewards for increased market value.

Equity grant guidelines and timing.  We award equity under three programs: a new hire grant program, a general grant program and a recognition grant program. Each year the compensation committee establishes guidelines and reviews our philosophy for granting equity under each program to determine appropriate and competitive grant levels. We have in place mechanisms for each of our three equity programs to ensure that awards are not back-dated. We have established processes, discussed below, for approving, dating and pricing new hire and recognition awards. Each year the committee evaluates the use of equity as a compensation tool, considering employee eligibility and past award practice, and sets a budget to manage its use. For 2008, the committee decided to continue a broad-based granting philosophy, award both stock options and restricted stock units, and manage to a maximum of 2.25% of shares outstanding for the combined programs.

New Hire Equity Grants.  We utilize a new hire equity grant program as an attraction tool in the hiring process for certain employees and executives throughout the year. Each year the compensation committee approves the total pool of shares available for the program. The committee has approved a new hire grant matrix, based on salary level, which determines the number of stock options and RSUs that may be granted to eligible new employees, other than executive officers, when they are hired. The committee has authorized our senior vice president, chief human resources officer to pre-approve and administer new hire grants pursuant to the matrix. The committee reviews all new hire grants on an annual basis. Grants to newly hired executive officers require specific approval by the committee prior to grant. Awards to employees who are hired on or prior to the 15th of each month are granted and priced (using the closing price of our stock) on the 15th (or next business day if the stock market is not open on the 15th) of the month of the employee’s date of hire. Awards to employees who are hired after the 15th of the month are granted and priced (using the closing price of our stock) on the 15th (or next business day if the stock market is not open on the 15th) of the month following the employee’s date of hire.

General Equity Grant.  Our largest equity program, which includes executive officers and other employees, is a broad-based equity grant of stock options and RSUs pursuant to an overall long-term equity incentive compensation plan. Such grants have covered approximately 89% of the shares granted during the calendar year for the past few years and have been awarded to approximately 98% of our worldwide employees. Each year the compensation committee decides if it is going to approve a broad-based equity grant and if so, plans for it to occur on the date of the annual shareholders meeting. Our bylaws call for the annual meeting to be held on the fourth Thursday of May or as otherwise determined by the board. The date of these annual meetings is set months in advance as part of the normal scheduling process for the board and its committees. This grant is not timed to coincide with the release of any material non-public information. The committee pre-approves a grant matrix, based on employee base salary and individual performance review ratings, that determines the number of options and/or RSUs that may be awarded to each eligible employee, other than the executive officers. To determine executive officer grants, the committee considers peer group proxy and survey data. The exercise price of the stock option grant is pre-approved by the committee and set as the closing price of our stock on the date of the grant, which is the date of the annual shareholders meeting.

For our general grant in 2008, awards were comprised of either a combination of stock options and RSUs or just RSUs. Combination awards were granted 50% in stock options and 50% in RSUs, applying a 3:1 ratio such that one RSU was awarded for every three stock options. RSU awards were determined under the same formula as the combination awards.

Recognition Stock Option Grants.  We also have a long-term equity incentive program, utilizing stock options, to recognize those employees who demonstrate excellence and outstanding achievement during the year. Executive officers are not eligible for this program. Each year the compensation committee approves a total pool of stock options available for the recognition stock option program and has authorized our senior vice president, chief human resources officer to approve the individual grants for the recognized employees. The individuals are nominated and vetted through an approval process that includes their immediate supervisor, the executive in charge of the business unit or function and our human resources department. At each meeting, the committee reviews all recognition grants that have been awarded since its last meeting. All recognition grants approved by the senior vice president, chief human resources officer by no later than one day prior to each quarterly earnings announcement are granted, and the exercise price set as, the closing price of our stock on the third business day following such earnings announcement by the company.

Mr. Termeer’s compensation.  At its meeting in December 2007, the compensation committee set executive base and target incentive cash compensation levels for 2008. In setting Mr. Termeer’s cash compensation, the committee considered cash compensation levels of CEOs in our peer group, survey data provided by its executive compensation consultant, and Mr. Termeer’s individual performance over the past year relative to our business strategy. The committee also considered secondary factors, including Genzyme’s sustained strong financial performance during Mr. Termeer’s tenure, and Mr. Termeer’s cash and equity compensation during the past 12 years. In setting his salary and target cash incentive for 2008,

the committee determined that Mr. Termeer’s leadership was directly responsible for both the short-term and sustained performance and growth of the company. To reflect this, the committee decided to increase Mr. Termeer’s overall cash compensation for 2008, both salary and target incentive compensation, by 5.7% to $3,476,550. This increase aligns with the company’s overall compensation budget, which we manage to 5.5%, and is comparable to industry norms.

The compensation committee believes that an emphasis on cash incentive compensation tied to corporate performance is appropriate for a chief executive officer. Accordingly, Mr. Termeer’s level of short-term incentive compensation should continue to reflect Genzyme’s pay-for-performance philosophy under which his target annual incentive cash compensation makes up more than half of his potential total cash compensation. The committee set Mr. Termeer’s base salary at $1,580,250 and his cash incentive target at $1,896,300. The actual cash incentive award paid to Mr. Termeer may be lower or higher than target based on actual performance for the year. Of this amount, approximately 60%, or $1,137,780 is tied to corporate financial performance and 40%, or $758,520 is tied to individual performance. The corporate financial performance component is payable based on the extent to which we achieve the operating income goal set by the board in connection with approving the 2008 annual budget. The committee generally assesses the payment of Mr. Termeer’s individual cash incentive target based on his strategic management of the company and its operations in achieving a long-term, sustainable business strategy.

In setting Mr. Termeer’s cash compensation for 2008, the committee noted that earnings for 2007 were forecasted to close the year at approximately 20% growth and identified the following items that were consistent both with our business strategy and performance:

Acquisitions/Product Growth

·Late stage clinical trials of Mozobil in non-Hodgkin’s lymphoma and multiple myeloma and Synvisc-One met their primary endpoints;

·Renvela, the next generation Renagel, was approved for sale in the U.S.;

·Investments in the genetics and diagnostics businesses resulted in a revenue increase of 19%;

·Three-year analysis demonstrated a robust, highly statistically significant treatment effect of alemtuzumab for multiple sclerosis compared to Rebif®;

·The acquisition of Bioenvision provided us with the exclusive, worldwide rights to clofarabine; and

·Alemtuzumab for the treatment of multiple sclerosis moved into phase 3 trials.

Strategic Management

·Mr. Termeer continued to manage toward sustainable future growth as demonstrated by strong commercial activity, expansion in critical markets such as China and India, continued opportunistic acquisition and licensing strategy, strengthening science, continued breadth and depth through the product pipeline, and focused investment in research and development growth.

Operational Management

·A continued effort to grow and expand Genzyme’s global manufacturing facilities, and

·A continued effort to expand and strengthen global marketing and sales distribution.

In May 2008, the compensation committee awarded an equity grant to Mr. Termeer comprised of stock options and RSUs. The committee considers Mr. Termeer’s equity awards “at risk” compensation and believes it is appropriate for equity awards to comprise a significant portion of Mr. Termeer’s total compensation. The committee referenced CEO equity data from proxy materials of the company’s peer group provided by Towers Perrin to guide their analysis. The committee reviewed Mr. Termeer’s performance and the long-range performance and growth of the company, noting the following specific key performance measures from 2007:

·Genzyme’s revenues increased to $3.8 billion, representing a 20% year-to-year increase with strong positioning for 2008;

·Multiple clinical trials met end points, such as Mozobil in non-Hodgkin’s lymphoma and multiple myeloma, and Synvisc-One and alemtuzumab for multiple sclerosis progressed to phase 3 trials;

·The successful launch of Myozyme, the most rapid launch of any of our enzyme replacement therapies, and Renvela’s approval in the U.S.;

·Strong growth in the genetics and diagnostic businesses;

·Communications with investors on long-term growth objectives, sustainability, and financial commitments of Genzyme’s goal of 20% compound average non-GAAP earnings growth from 2006 through 2011;

·Strong commercial activity around the world;

·Expansion into key markets, including China and India;

·A strong investment in research and development;

·Continued opportunistic acquisition strategy; and

·Continued development of the executive team through reorganization of product responsibilities.

As a result of their analysis, and to recognize Mr. Termeer’s management of the operations of the company toward long-term sustainable growth, the compensation committee concluded that providing a grant equal to the same number of stock options and RSUs as was granted in 2007 would be both appropriate and competitive with the peer group. The committee granted Mr. Termeer stock options to purchase 200,000 shares of our stock and RSUs for 67,000 shares. The committee applied the same formula that was applied to all other employees who were granted stock options and RSUs at the same time, constructing an award that provided for 50% of the grant in stock options and 50% in RSUs, applying a 3:1 ratio such that one RSU was awarded for every three stock options.

The following table summarizes the components of 2008 compensation decisions approved by the committee as a percentage of total compensation for Mr. Termeer:

	2008 ($)(1)	% of Total Compensation
Base salary	1,580,250	12	%
Target cash incentive
—corporate performance	1,137,780
—individual performance	758,520
Total target cash incentive	1,896,300	15	%
Total target cash compensation	3,476,550	27	%
Value of equity awards(2)
—stock options	4,454,400	36	%
—RSUs	4,588,160	37	%
Total equity value	9,042,560	73	%
Total compensation	12,519,110	100	%

(1)Represents total target compensation for 2008 only. Actual cash incentive paid in 2009 for 2008 performance is disclosed in the Summary Compensation Table on page 24. Does not reflect other amounts included in the Summary Compensation Table, such as expense of equity awards vesting in 2008 that were granted in 2008 and in prior years or any other compensation.

(2)Based on grant date fair value, discussed on pages 24-25 of this proxy statement.

Compensation for other named executive officers.  To determine executive compensation for 2008, the compensation committee reviewed the compensation data of our peer group companies, as well as compensation surveys of

the pharmaceutical and biopharmaceutical industries and general survey data. The committee looks at the data to evaluate the appropriateness and competitiveness of our pay positioning, but does not target a certain level of compensation. The committee’s objective is to ensure that total compensation for our executive positions is appropriate and reflects the individual performance of each executive.

The approach to compensation for our named executive officers also reflects our non-hierarchical management structure. We employ a relatively flat management structure compared with the more traditional multi-tiered management structures employed by many other companies. Our executive officers make up an operating committee that includes business, legal, medical and scientific officers. This operating committee meets regularly to discuss the ongoing management of the company as well as strategic planning for the company’s development and future growth. They have an integral role in helping Mr. Termeer chart the future of the company. Cash and equity compensation for members of this group falls within relatively narrow ranges, reflecting the flat management layer directly below the CEO. Due to the way this group operates, the differential between the compensation levels for our named executive officers and the compensation for Mr. Termeer is greater than that seen in the more traditional hierarchical compensation structures employed by many other companies.

For the named executive officers other than himself, Mr. Termeer discusses with the compensation committee each officer’s individual performance and his recommendation for merit increases and target annual cash incentive compensation amounts. Because the named executive officers are responsible for implementing our strategic direction, Mr. Termeer’s recommendations focus on sustainable, strategic decision-making capabilities for each individual relative to the company as a whole and each individual’s areas of responsibility. Mr. Termeer’s recommendations for 2008 included an emphasis on incentive compensation to reflect a pay for performance structure. The committee also reviews a two-year history of cash compensation for each named executive officer. The committee reviews Mr. Termeer’s recommendations and makes its cash compensation decisions based on each officer’s performance, its assessment of that individual’s performance relative to the group and each officer’s compensation in light of competitive market information. At its December 2007 meeting, the committee approved base salary increases ranging from 3.7 - 4.3% for 2008 for the named executive officers other than Mr. Termeer.

A significant portion of executive compensation consists of annual cash incentive awards. The annual cash incentive targets are tied to both corporate performance and performance in individual areas of responsibility. To reflect an emphasis on pay for performance, approximately 79% of the annual cash incentive target for the named executive officers, other than Mr. Termeer, is tied to corporate financial performance. The corporate financial performance component is payable based on the extent to which we achieve the operating income goal set by the board in connection with approving the 2008 annual budget.

For our named executive officers, equity is used as an incentive to manage the business to realize and maximize long-term shareholder value. In May 2008, to determine the number of options and RSUs to grant to each named executive officer, the committee considered:

·Mr. Termeer’s recommendations regarding each named executive officer’s performance in 2008 and assessment of the officer’s long-term potential at Genzyme;

·proxy data from our peer group;

·Watson Wyatt’s custom survey of long-term incentive practices in the biotechnology industry;

·our expected business position for the next several years; and

·our equity granting history for the last three years.

The committee approved equity awards of 45,000 stock options and 15,000 RSUs for each of our named executive officers, other than Mr. Termeer. The committee concluded that providing a grant equal to the same number of stock options and restricted stock units as was granted in 2007 would be both appropriate and competitive with our peer group. The committee applied the same formula that was applied to all other employees who were granted stock options and RSUs at the same time, constructing awards that provided for 50% of the grant in stock options and 50% in RSUs, applying a 3:1 ratio such that one RSU was awarded for every three stock options.

The following table summarizes the components of 2008 compensation decisions approved by the committee as a percentage of total compensation for the named executive officers listed in the “Summary Compensation Table” on page 24 of this proxy statement:

	M. Wyzga		E. Collier		G. Gemayel(1)		S. Smith		P. Wirth
Base salary	17	%	18	%	51	%	16	%	23	%
Target cash incentive	16	%	16	%	49	%	16	%	15	%
Total target cash compensation	33	%	34	%	100	%	32	%	38	%
Value of equity awards(2)	67	%	66	%	N/A		68	%	63	%
Total compensation(3)	100	%	100	%	100	%	100	%	100	%

(1)Dr. Gemayel resigned from the company effective June 1, 2008 and did not receive an equity award in 2008.

(2)Based on grant date fair value, discussed on pages 24-25 of this proxy statement.

(3)Represents total target compensation for 2008 only. Actual cash incentives paid in 2009 for 2008 performance are disclosed in the Summary Compensation Table on page 24. Does not reflect other amounts included in the Summary Compensation Table, such as expense of equity awards vesting in 2008 that were granted in 2008 and in prior years or any other compensation.

Without sustained growth and positive stock price performance, our executives carry the risk that they will not be able to realize significant gains from all of their equity-based awards. Our long-term incentive program, by design, provides a link to shareholder interests and to the company’s long-term performance. The compensation committee does not consider realized gains from prior stock option or RSU awards in its compensation decisions, for either cash or equity, as such awards recognize past achievement. While we encourage share ownership through this program, we do not have a formal share ownership policy. Historically, on average, our named executive officers wait more than six years before exercising stock options. In addition, we do not have a specific policy regarding hedging the economic risk of share ownership, but advise our executive officers about the potential for violations under the short-sale rules of the Exchange Act.

Executive Employment Agreements.  Messrs. Termeer and Wirth each have an initial three-year employment agreement that automatically extends by one year each December 31st, unless written notice of non-renewal is given. These agreements were amended and restated effective December 31, 2008 to (1) comply with, or ensure exemption from, Section 409A of the Code, (2) align the change in control definition with the definition used in the severance agreements for our other executive officers, and (3) reflect current Genzyme compensation and benefits practices. Each agreement provides that the board, or a duly appointed committee of the board, shall set salary annually, and that such base salary shall not be lower than the base salary for the preceding calendar year. Both agreements provide:

·certain life and disability insurance benefits;

·eligibility to participate in the company’s annual cash incentive plan;

·eligibility to participate in the company’s equity incentive plans;

·certain payments and benefits for termination without cause, with or without a change in control event, or termination by the executive for good reason following a change in control;

·accelerated vesting of equity awards in the event of termination without a change in control event without cause or due to death or disability; and

·confidentiality, non-competition and ownership of inventions provisions.

Executive Severance Agreements.  The committee believes that it is in the best interests of the company and its shareholders to ensure the continued dedication of our named executive officers, should the company be in the situation of facing a change in control. Such a situation would require our named executive officers to remain highly focused and attentive to managing the operations of the company. The financial security provided by severance benefits can mitigate the inevitable distractions created by the personal uncertainties and risks created by a pending or threatened change in control.

Other than Messrs. Termeer and Wirth, whose severance arrangements are included in their employment agreements and described above, we have severance agreements with all of our named executive officers. These agreements have an initial one-year term and renew automatically each December 31st for an additional one-year period, unless written notice of non-renewal is given. Under these agreements, payments will be made upon the involuntary termination of the named

executive officer’s employment by us without cause or by the named executive officer for good reason following a change in control.

For a more complete description and quantification of benefits payable to our named executive officers upon and following termination of employment see “Potential Payments Upon Termination or Change in Control” on pages 33-37.

None of the agreements provide for tax gross-up payments, which allows us to avoid the often significant costs that could be involved in gross-up payments related to change in control. None of Mr. Termeer’s, Mr. Wirth’s, or any named executive officer’s agreements contain any clawback provisions.

Executive separation arrangement.  Dr. Georges Gemayel, Executive Vice President responsible for our Renal, Therapeutics (excluding our lysosomal storage disorders business unit), Transplant and Biosurgery business units, left the company effective June 1, 2008. Under a separation agreement with Dr. Gemayel, he received a lump sum payment of $748,000 which was an amount equal to 12 month’s salary and 50% of his 2008 cash incentive target, and payment for his accrued unused vacation pay. He also received accelerated vesting of options due to vest in May 2009 and an extension of the period of time to exercise his vested options to May 31, 2009. In addition, he received accelerated vesting of two-thirds of unvested RSUs awarded to him in May 2007.

Tax law limits on executive compensation.  Section 162(m) of the Code generally does not permit Genzyme a federal income tax deduction for taxable year compensation in excess of $1,000,000 paid to each of our chief executive officer and our three highest paid executive officers other than the chief executive officer and the chief financial officer. Certain performance-based compensation that is awarded under a plan, the material terms of which have been approved by shareholders is exempt from the deduction limit. Although the 2008 salary and annual cash incentive awards paid to our named executive officers do not qualify for the performance-based compensation exemption, our shareholders have approved the 2001 and 2004 Equity Incentive Plans, which are designed to allow us to deduct the compensation expense related to awards granted to our named executive officers under those plans. We have in the past and may in the future award compensation that is not fully deductible under Section 162(m) when we view such compensation as consistent with our compensation policies and in the best interests of the company and its shareholders.

This compensation discussion and analysis is intended to provide an overview and analysis of the policies and decisions made for executive compensation. We believe that the decisions of the compensation committee and the company follow a deliberate and thoughtful process and are aligned with both the short- and long-term objectives of the corporation and its shareholders. The following tables and disclosures are intended to support and augment this discussion.

SUMMARY COMPENSATION TABLE

for the year ended December 31, 2008

Name and Principal Position	Year	Salary ($)	Stock Awards ($)(1)(3)	Option Awards ($)(2)(3)	Non-Equity Incentive Plan Compensation ($)(4)	All Other Compensation ($)(5)	Total ($)
Henri A. Termeer	2008	1,578,514	2,325,152	7,791,889	1,962,725	115,502	13,773,782
Chief Executive Officer(6)	2007	1,503,620	839,784	10,040,452	2,142,000	105,773	14,631,629
	2006	1,431,938	—	19,166,150	1,725,500	125,330	22,448,918
Michael S. Wyzga	2008	509,538	520,559	1,486,258	489,500	13,347	3,019,202
Executive Vice President;	2007	489,577	188,011	1,660,709	560,000	11,230	2,909,527
Chief Financial Officer	2006	467,654	—	1,940,886	433,125	11,000	2,852,665
Earl M. Collier, Jr.	2008	557,515	520,559	1,554,233	489,500	13,800	3,135,607
Executive Vice President	2007	536,577	188,011	3,333,115	555,000	11,250	4,623,953
	2006	514,615	—	2,068,913	433,125	11,000	3,027,653
Georges Gemayel	2008	224,277	437,454	1,523,318	—	798,291	2,983,340
Executive Vice President(7)	2007	489,577	188,011	1,861,918	555,000	11,250	3,105,756
	2006	467,654	—	1,986,398	438,125	11,000	2,903,177
Sandford D. Smith	2008	489,538	520,559	1,390,349	489,500	13,800	2,903,746

Executive Vice President	2007	469,654	188,011	2,979,219	555,000	11,250	4,203,134
	2006	451,674	—	1,526,355	389,583	—	2,367,612
Peter Wirth	2008	734,331	520,559	1,486,258	489,500	15,711	3,246,359
Executive Vice President(8)	2007	705,423	188,011	1,660,709	560,000	13,161	3,127,304
	2006	675,500	—	2,070,880	433,125	12,913	3,192,418

(1)Amounts represent the FAS 123R compensation expense, excluding an estimate of forfeitures related to service-based vesting conditions, recognized in our financial statements with respect to RSUs granted in 2008 and 2007. Compensation expense for RSUs is based on the grant date fair market value of the award and is recognized over the service period, which generally represents the vesting period. The RSUs granted on May 22, 2008 had a grant date fair market value of $68.48 per share. The RSUs granted on May 24, 2007 had a grant date fair market value of $62.16 per share.

(2)Amounts represent the FAS 123R compensation expense, excluding an estimate of forfeitures related to service-based vesting conditions, recognized in our financial statements with respect to the vested portion of stock options granted in 2008, 2007 and 2006 plus vesting that occurred in 2008, 2007 and 2006 for options granted in previous years. In addition, FAS 123R requires us to fully expense stock options when there is no risk of forfeiture of the award. Messrs. Termeer, Collier and Smith have each reached a company retirement eligibility threshold for option awards which provides for acceleration of vesting for stock options at termination of employment other than for cause. Although option grants to Messrs. Termeer, Collier and Smith vest over four years and the company does not permit the exercise of unvested options, these grants have been fully expensed in 2008, 2007 and 2006 for Mr. Termeer and in 2008 and 2007 for Messrs. Collier and Smith. Options awarded prior to 2006 were granted prior to our adoption of FAS 123R and, therefore, will continue to be expensed over the requisite nominal vesting period.

The option awards expense was determined using the Black-Scholes option valuation model, which estimates the value of an equity award using subjective assumptions which can vary over time. Valuation information for the 2008 option awards can be found below in the “Grants of Plan-Based Awards” table on page 29. For a more complete discussion of FAS 123R and the relevant assumptions we use to calculate the grant date fair value of option awards for 2008, 2007 and 2006, see the section “Accounting for Stock-Based Compensation” in “Note A. Summary of Significant Accounting Policies” and “Note M. Stockholders’ Equity” of the “Notes To Consolidated Financial Statements” in our 2008 Annual Report on Form 10-K.

For a discussion of the relevant FAS 123 assumptions we used to calculate the grant date fair value of option awards granted from 1997 through 2005, which had vesting in 2008, 2007 and 2006, see the section “Accounting for Stock-Based Compensation” in “Note A. Summary of Significant Accounting Policies” and “Note K. Stockholders’ Equity” of the “Notes To Consolidated Financial Statements” in our 1997 Annual Report on Form 10-K and “Accounting for Stock-Based Compensation” in “Note A. Summary of Significant Accounting Policies” and “Note N. Stockholders’ Equity” of the “Notes To Consolidated Financial Statements” in our 2002 and 2005 Annual Reports on Form 10-K.

(3)Option award amounts include the following expense for options vested or expensed in 2008:

Grant Date	H. Termeer Expense ($)	M. Wyzga Expense ($)	E. Collier Expense ($)	G. Gemayel Expense ($)	S. Smith Expense ($)	P. Wirth Expense ($)
5/31/01	5,693	—	—	—	—	—
5/27/04	805,729	141,878	141,878	141,878	99,840	141,878
5/26/05	2,526,067	410,115	410,115	463,899	288,269	410,115
5/25/06	—	402,190	—	577,915	—	402,190
5/24/07	—	209,162	—	339,626	—	209,162
5/22/08	4,454,400	322,913	1,002,240	—	1,002,240	322,913
Total	7,791,889	1,486,258	1,554,233	1,523,318	1,390,349	1,486,258

Option award amounts include the following expense for options vested or expensed in 2007:

Grant Date	H. Termeer Expense ($)	M. Wyzga Expense ($)	E. Collier Expense ($)	G. Gemayel Expense ($)	S. Smith Expense ($)	P. Wirth Expense ($)
5/25/00	3,876	—	—	—	—	—
5/31/01	13,670	—	—	—	—	—
5/29/03	875,454	165,875	165,875	—	82,938	165,875
8/18/03	—	—	—	367,085	—	—
5/27/04	1,989,293	350,289	350,289	350,288	246,500	350,289
5/26/05	2,517,799	408,772	408,772	408,772	287,325	408,772
5/25/06	—	400,868	1,364,098	400,868	1,318,375	400,868
5/24/07	4,640,360	334,905	1,044,081	334,905	1,044,081	334,905
Total	10,040,452	1,660,709	3,333,115	1,861,918	2,979,219	1,660,709

In 2007, each of Messrs. Collier and Smith reached a retirement eligibility threshold which provides for acceleration of vesting of stock options at termination of employment other than for cause. Mr. Termeer reached this threshold in 2006. Amounts above represent the full FAS 123R expense for options granted in 2006 which do not fully vest until 2010 and in 2007 which do not fully vest until 2011.

Option award amounts include the following expense for options vested or expensed in 2006:

Grant Date	H. Termeer Expense ($)	M. Wyzga Expense ($)	E. Collier Expense ($)	G. Gemayel Expense ($)	S. Smith Expense ($)	P. Wirth Expense ($)
1/30/97	—	—	75	—	—	—
5/25/00	9,757	—	—	—	—	—
5/31/01	13,670	—	—	—	—	—
5/30/02	845,157	130,697	258,649	—	99,216	260,691
5/29/03	2,144,568	406,339	406,339	—	203,170	406,339
8/18/03	—	—	—	582,548	—	—
5/27/04	1,992,545	350,861	350,861	350,861	246,902	350,861
5/26/05	2,521,933	409,443	409,443	409,443	287,797	409,443
5/25/06	11,638,520	643,546	643,546	643,546	689,270	643,546
Total	19,166,150	1,940,886	2,068,913	1,986,398	1,526,355	2,070,880

In 2006, Mr. Termeer reached a retirement eligibility threshold which provides for acceleration of vesting of stock options at termination of employment other than for cause. Amounts above represent the full FAS 123R expense for options awarded in 2006, even though the options do not fully vest until 2010.

In addition to any expense for options that may be granted in future years, we will incur the following expense for options granted in prior years to the named executive officers as they vest:

Year	H. Termeer Expense ($)	M. Wyzga Expense ($)	E. Collier Expense ($)	S. Smith Expense ($)	P. Wirth Expense ($)
2009	1,008,773	974,570	163,777	115,119	974,570
2010	—	568,776	—	—	929,588
2011	—	282,496	—	—	—
2012	—	78,317	—	—	—

In addition to any expense for RSUs that may be granted in future years, we will recognize expense over the vesting period for RSUs granted in 2008 and 2007 to the named executive officers as follows:

Year	H. Termeer Expense ($)	M. Wyzga Expense ($)	E. Collier Expense ($)	S. Smith Expense ($)	P. Wirth Expense ($)
2009	2,916,337	652,916	652,916	652,916	652,916
2010	2,076,595	464,905	464,905	464,905	464,905
2011	595,012	133,208	133,208	133,208	133,208

(4)In February 2009, the compensation committee evaluated the achievement of the 2008 annual cash incentive targets. For 2008, the company exceeded the operating income goal established in the 2008 budget by 1% and, in accordance with the corporate financial performance formula, the committee awarded the corporate component of the annual cash incentive at 102.5% of target for all of the named executive officers. In addition, Mr. Termeer made recommendations to the committee for the individual performance component of each named executive officer’s annual incentive based on his evaluation of each officer’s performance for the year. Mr. Termeer discussed the company’s 2008 performance and each executive’s contribution in attaining strong financial results, continued

product growth, and a continued development of a strong product pipeline. The committee reviewed and discussed the following recommendations and specific comments from Mr. Termeer related to each of the named executive officers:

·Mr. Wyzga: Mr. Termeer noted Mr. Wyzga’s strong leadership in managing the financial operations of the company, his strong management of the treasury function, and his leadership for a number of significant IT projects.

·Mr. Collier: Mr. Termeer discussed Mr. Collier’s value and contribution to the company’s strategic direction, his role in the successful integration of Bioenvision, Inc. and his contribution to the outstanding growth and performance of our genetics division.

·Mr. Smith: Mr. Termeer noted the impressive manner in which Mr. Smith provides leadership and continued growth and expansion of the commercial businesses around the world in a dynamic and complex environment from both a product and geographical perspective. Mr. Termeer also highlighted Mr. Smith’s unique management style which has allowed him to expand his organization while adapting to local needs.

·Mr. Wirth: Mr. Termeer noted Mr. Wirth’s invaluable role as leader and strategic thought partner, his significant contribution in the structure and execution of all M&A and board transactions, and his excellent guidance of all legal issues.

Following their review and assessment of each officer’s performance, the committee awarded the individual performance component to the named executive officers other than Mr. Termeer at 100% of target. Aggregate total bonuses for the named executive officers, other than Mr. Termeer, totaled 102% of target.

Mr. Termeer’s individual performance target for 2008 was set at 40% of his total cash incentive, or $758,520. The compensation committee awarded Mr. Termeer 105% of his individual cash incentive for a total payment of $796,500. The committee considered the following accomplishments which led to an operationally and strategically strong year in determining the individual portion of Mr. Termeer’s 2008 annual cash incentive payment:

Financial Performance.

·Strong financial performance in 2008, with revenues increasing approximately 20% over 2007 and strong cash flow in a time when the importance of cash has increased.

Acquisitions/Product Growth.

·The approval of Mozobil in the United States and continued progress of multiple products in clinical trials;

·Entry into a collaboration with Isis Pharmaceuticals, Inc. under which we acquired the exclusive, worldwide rights to develop mipomersen, responding to the unmet medical need for severe hypercholesterolemia;

·Management of the integration of prior transactions such as the acquisition of Bioenvision;

·Entry into a collaboration with PTC Therapeutics, Inc. under which we acquired rights to commercialize outside of the U.S. and Canada ataluren (formerly PTC124), a potential treatment for Duchenne muscular dystrophy and cystic fibrosis;

·Entry into a collaboration with Osiris Therapeutics, Inc. under which we acquired rights to commercialize outside of the U.S. and Canada Prochymal and Chondrogen, late-stage adult stem cell treatments with potential to treat a wide range of diseases such as graft vs. host disease, Crohn’s disease, type 1 diabetes, acute myocardial infarction, and osteoarthritis of the knee; and

·Management of issues associated with approval of Myozyme (aglucosidase alfa) produced at the 4000 liter scale in Europe and approval of Lumizyme (aglucosidase alfa) produced at the 2000 liter scale in the U.S.

Operational Management.

·Reorganized key commercial businesses, which we believe will help strengthen the long-term sustainability of the company;

·Expanded the scope and responsibilities of the internal management committee responsible for prioritizing R&D initiatives; and

·Recognition of the company by Science Magazine as the third best science organization in the world in which to work.

Facilities

·Maintained a continued focus on building and strengthening the development of our global infrastructure with a special focus on environmentally responsible facilities. (5)  All other compensation above includes company contributions made under our retirement savings plan, a 401(k) plan.

(6)All other compensation for Mr. Termeer for 2008, 2007 and 2006 includes insurance premiums totaling $28,103 in each year that we paid for life and disability insurance benefits. In addition, for security purposes we provide a driver to Mr. Termeer for commuting to and from work and work-related events. The cost to the company of providing this benefit to Mr. Termeer was $73,599 for 2008, $66,420 for 2007 and $60,845 for 2006. This cost is based on the driver’s salary plus vehicle expenses, including gas, mileage, and vehicle lease expense. Mr. Termeer also received a grossed-up taxable benefit of $25,382 in 2006 for personal use of the corporate aircraft.

(7)Dr. Gemayel left the company effective June 1, 2008. For a description of payments made to Dr. Gemayel under his separation agreement see “Executive separation arrangement” on page 35.

(8)For Mr. Wirth, all other compensation includes insurance premiums of $1,911 for 2008 and 2007 and $1,913 for 2006 that we paid for life insurance benefits.

Our policy on the use of corporate aircraft.  We pay for travel on private and commercial aircraft for our executives, but only if such travel is directly related to the performance by the executive of his or her job. We lease an aircraft for business travel and pay for the service based on the route traveled regardless of the passenger load. Employees authorized to use the aircraft for business travel are allowed to bring family members or guests along on the trip provided they have the prior approval of the chief executive officer and the chief financial officer. When an employee brings a family member or guest along on a business trip and does not reimburse the company for such costs, then the employee is considered to have received a benefit equal to the value of the trip. We use the equivalent cost of first class airfare method to calculate the value of this benefit. The value of the trip is determined by data on an equivalent first class trip as quoted by our independent travel agency.

In certain circumstances we consider the presence of spouses at business functions integral to the success of a business trip. A significant portion of our economic growth includes expansion into emerging markets, such as China and Southeast Asia. This expansion activity often includes ceremonial meetings with dignitaries of local governments. Spouses of our representatives are expected to attend these ceremonial meetings by the local dignitaries. Generally, the success of the meetings and the benefit to Genzyme is deemed to be substantial and therefore the cost of the spouse’s flight is considered a normal business expense and no taxable fringe benefit is created. For similar reasons, we view the spouse’s flight as integrally and directly related to the performance of the executive’s duties and, consequently, do not consider the cost to represent a perquisite.

The specific facts and circumstances of each trip that includes spousal travelers are reviewed by us and may require the value of the spousal travel to be declared income to the employee for financial and/or tax reporting. When appropriate, the value of the travel will be reported as income to the employee and will be grossed up to pay the taxes due for this additional income.

GRANTS OF PLAN-BASED AWARDS

for the year ended December 31, 2008

						All Other	All Other
						Stock	Option			Grant
						Awards:	Awards:	Exercise		Date Fair
						Number of	Number of	or Base		Value of
			Estimated Future Payouts Under			Shares of	Securities	Price of		Stock and
	Approval	Grant	Non-Equity Incentive Plan Awards(1)			Stock or	Underlying	Option		Option
Name	Date	Date	Threshhold ($)	Target ($)	Maximum ($)	Units (#)	Options (#)	Awards ($/Sh)		Awards ($)
Henri A. Termeer		N/A	—	1,896,300	2,465,190
	5/21/08	5/22/08				67,000				4,588,160
	5/21/08	5/22/08					200,000	$	68.48	4,454,400
Michael S. Wyzga		N/A	—	480,000	670,000
	5/21/08	5/22/08				15,000				1,027,200
	5/21/08	5/22/08					45,000	$	68.48	1,002,240
Georges Gemayel		N/A	—	480,000	670,000	—	—	N/A		N/A
Earl M. Collier, Jr.		N/A	—	480,000	670,000
	5/21/08	5/22/08				15,000				1,027,200
	5/21/08	5/22/08					45,000	$	68.48	1,002,240
Sandford D. Smith		N/A	—	480,000	670,000
	5/21/08	5/22/08				15,000				1,027,200
	5/21/08	5/22/08					45,000	$	68.48	1,002,240
Peter Wirth		N/A	—	480,000	670,000
	5/21/08	5/22/08				15,000				1,027,200
	5/21/08	5/22/08					45,000	$	68.48	1,002,240

(1)Represents target payout under our annual cash incentive plan for 2008. Actual amounts paid in February 2009 are included in the “Non-Equity Incentive Plan Compensation” column of the Summary Compensation Table on page 24. The maximum amounts assume a payout of 150% of the corporate component of the named executive officer’s annual cash incentive. The annual cash incentive program is described in the “Compensation Discussion and Analysis” on page 15.

On May 22, 2008, stock options and RSUs were granted to the named executive officers, at the same time that stock options and RSUs were granted to all qualified, eligible employees of the company. Stock option awards to Messrs. Collier, Smith and Wyzga were made under the 2001 Equity Incentive Plan. All other awards were made under the 2004 Equity Incentive Plan. The awards were approved by our compensation committee at a meeting held on May 21, 2008. The stock options have an exercise price of $68.48 per share, which was the closing price of our stock on May 22, 2008, the date of grant. The options have a ten-year term and vest 20% on the date of grant with an additional 20% vesting annually over the next four years on the anniversary of the date of grant. For Messrs. Wyzga and Wirth, RSUs vest 100% on the third anniversary of the date of grant. RSUs for Messrs. Termeer, Collier and Smith, who have reached a retirement eligibility threshold, vest in one-third increments on each of the next three anniversaries of the date of grant.

The grant date fair value of the stock options granted in 2008 was $22.27 per share, computed in accordance with FAS 123R and based on the Black-Scholes option pricing model. The grant date fair value of the RSUs granted in 2008 was $68.48 per share, which was the closing price of our stock on the date of grant. We incorporate our discussion of the relevant assumptions we use to calculate the grant date fair value of equity awards into this section by reference from the section “Accounting for Stock-Based Compensation” in “Note A. Summary of Significant Accounting Policies” and “Note M. Stockholders’ Equity” of the “Notes To Consolidated Financial Statements” in our 2008 Annual Report on Form 10-K.

The stock option awards for the named executive officers include vesting acceleration in the event of termination as a result of disability or death, or upon a change in control of the company. The RSU awards for Messrs. Termeer and Wirth include vesting acceleration in the event of termination as a result of disability or death, or upon a change in control of the company. The 2008 RSU awards for the other named executive officers, however, include vesting acceleration in the event of termination as a result of death or upon a change in control of the company, but not for disability. For stock option awards, in the event of termination as a result of disability or death, the named executive officers, or their beneficiaries, will have one year to exercise vested options unless the options otherwise would expire under their stated terms.

In addition, if the named executive officer reaches the age of 60 and has completed five years of service with the company, at termination of employment for any reason other than cause, vesting of stock options will be accelerated and the executive officer will have three years to exercise the options unless they otherwise would expire under their stated terms. This retirement eligibility provision does not apply to options granted before December 1, 2003. The named executive

officers do not have any acceleration of vesting provision relating to retirement eligibility for RSU awards. Nonstatutory options for the named executive officers are transferable to defined family members.

If a named executive officer leaves his employment with us for any reason other than death, disability, retirement (as described above) or following a change in control, he may exercise vested options for a period of 90 days from the date of termination. If terminated for cause, he may exercise vested options for a period of 90 days from the date of termination. Unvested options will be cancelled as of the date of termination. Stock options and RSUs for Messrs. Termeer and Wirth will also automatically vest if either one’s employment is terminated by the company without cause prior to a change in control.

OUTSTANDING EQUITY AWARDS AT FISCAL YEAR-END

for the year ended December 31, 2008

	Option Awards				Stock Awards
Name	Number of Securities Underlying Unexercised Options (#) Exercisable(1)	Number of Securities Underlying Unexercised Options (#) Unexercisable(1)(2)	Option Exercise Price ($)	Option Expiration Date	Number of Shares or Units of Stock That Have Not Vested(#)(3)	Market Value of Shares or Units of Stock That Have Not Vested($)(4)
Henri A. Termeer	1,224		467.56	1/25/2009	134,000	8,893,580
	4,148		95.76	1/25/2009
	4,719		223.18	8/26/2009
	400,000		26.50	5/25/2010
	8,421		226.83	5/25/2010
	500,000		53.47	5/31/2011
	12,362		126.59	5/31/2011
	5,614		274.31	5/31/2011
	600,000		32.52	5/30/2012
	6,181		85.74	5/30/2012
	7,017		41.50	5/30/2012
	475,000		46.24	5/29/2013
	460,000		43.90	5/27/2014
	340,000	85,000	62.98	5/26/2015
	240,000	160,000	58.50	5/25/2016
	80,000	120,000	62.16	5/24/2017
	40,000	160,000	68.48	5/22/2018

	Option Awards				Stock Awards
Name	Number of Securities Underlying Unexercised Options (#) Exercisable(1)	Number of Securities Underlying Unexercised Options (#) Unexercisable(1)(2)	Option Exercise Price ($)	Option Expiration Date	Number of Shares or Units of Stock That Have Not Vested(#)(3)	Market Value of Shares or Units of Stock That Have Not Vested($)(4)
Michael S. Wyzga	488		95.76	1/25/2009	30,000	1,991,100
	144		467.56	1/25/2009
	287		223.18	8/26/2009
	343		226.75	5/25/2010
	592		135.25	2/9/2011
	505		274.31	5/31/2011
	791		126.59	5/31/2011
	954		85.74	5/30/2012
	90,000		46.24	5/29/2013
	81,000		43.90	5/27/2014
	55,200	13,800	62.98	5/26/2015
	41,400	27,600	58.50	5/25/2016
	18,000	27,000	62.16	5/24/2017
	9,000	36,000	68.48	5/22/2018

	Option Awards				Stock Awards
Name	Number of Securities Underlying Unexercised Options (#) Exercisable(1)	Number of Securities Underlying Unexercised Options (#) Unexercisable(1)(2)	Option Exercise Price ($)	Option Expiration Date	Number of Shares or Units of Stock That Have Not Vested(#)(3)	Market Value of Shares or Units of Stock That Have Not Vested($)(4)
Earl M. Collier, Jr.	1,640		95.76	1/25/2009	30,000	1,991,100
	484		467.56	1/25/2009
	4,719		223.18	8/26/2009
	4,373		26.50	5/25/2010
	479		226.75	5/25/2010
	4,945		135.25	2/9/2011
	21,000		53.47	5/31/2011
	505		274.31	5/31/2011
	3,115		126.59	5/31/2011
	651		41.50	5/30/2012
	3,708		85.74	5/30/2012
	36,820		32.52	5/30/2012
	55,200	13,800	62.98	5/26/2015
	41,400	27,600	58.50	5/25/2016
	18,000	27,000	62.16	5/24/2017
	9,000	36,000	68.48	5/22/2018

	Option Awards				Stock Awards
Name	Number of Securities Underlying Unexercised Options (#) Exercisable(1)	Number of Securities Underlying Unexercised Options (#) Unexercisable(1)(2)	Option Exercise Price ($)	Option Expiration Date	Number of Shares or Units of Stock That Have Not Vested(#)(3)	Market Value of Shares or Units of Stock That Have Not Vested($)(4)
Sandford D. Smith	683		95.76	1/25/2009	30,000	1,991,100
	201		467.56	1/25/2009
	287		223.18	8/26/2009
	407		226.75	5/25/2010
	14,700		53.47	5/31/2010
	351		135.25	2/9/2011
	308		274.31	5/31/2011
	370		126.59	5/31/2011
	241		41.50	5/30/2012
	791		85.74	5/30/2012
	9,000		46.24	5/29/2013
	22,800		43.90	5/27/2014
	38,800	9,700	62.98	5/26/2015
	41,400	27,600	58.50	5/25/2016
	18,000	27,000	62.16	5/24/2017
	9,000	36,000	68.46	5/22/2018

	Option Awards				Stock Awards
Name	Number of Securities Underlying Unexercised Options (#) Exercisable(1)	Number of Securities Underlying Unexercised Options (#) Unexercisable(1)(2)	Option Exercise Price ($)	Option Expiration Date	Number of Shares or Units of Stock That Have Not Vested(#)(3)	Market Value of Shares or Units of Stock That Have Not Vested($)(4)
Peter Wirth	232,180		29.44	1/25/2009	30,000	1,991,100
	2,067		95.76	1/25/2009
	610		467.56	1/25/2009
	287		223.18	8/26/2009
	48,216		26.50	5/25/2010
	1,208		226.75	5/25/2010
	520		135.25	2/9/2011
	1,571		274.31	5/31/2011
	642		126.59	5/31/2011
	62,000		53.47	5/31/2011
	2,245		41.50	5/30/2012
	185,300		32.52	5/30/2012
	1,468		85.74	5/30/2012
	90,000		46.24	5/29/2013
	81,000		43.90	5/27/2014
	55,200	13,800	62.98	2/26/2015
	41,400	27,600	58.50	5/25/2016
	18,000	27,000	62.16	5/24/2017
	9,000	36,000	68.48	5/22/2018

(1)Includes stock options originally granted in our Biosurgery and Molecular Oncology tracking stocks which were converted into stock options for Genzyme Stock on June 30, 2003. A total of 88,293 of these converted options are exercisable with exercise prices from $41.50 to $467.56.

(2)Stock options vest 20% on the date of grant and 20% per year over four years on the anniversary of the date of grant. The grant date of the stock options is ten years prior to the option expiration date.

(3)The following table provides information with respect to the vesting of each outstanding RSU held by the named executive officers as of December 31, 2008:

RSU Vesting Date	H. Termeer	M. Wyzga	E. Collier	S. Smith	P. Wirth
May 22, 2009	22,333		5,000	5,000
May 22, 2010	67,000	15,000	15,000	15,000	15,000
May 24, 2010	22,333		5,000	5,000
May 22, 2011	22,334	15,000	5,000	5,000	15,000
Totals	134,000	30,000	30,000	30,000	30,000

(4)The market value of RSUs is based on a price of $66.37, which was the closing price of our stock on December 31, 2008.

OPTION EXERCISES AND STOCK VESTED

for the year ended December 31, 2008

	Option Awards		Stock Awards
Name	Number of Shares Acquired On Exercise (#)	Value Realized on Exercise ($)	Number of Shares Acquired on Vesting (#)	Value Realized On Vesting ($)
Henri A. Termeer	0	0	0	0
Michael S. Wyzga	29,390	1,364,557	0	0
Earl M. Collier, Jr.	106,200	3,542,220	0	0
Georges Gemayel	253,192	5,381,032	10,000	676,600
Sandford D. Smith	25,000	711,421	0	0
Peter Wirth	0	0	0	0

POTENTIAL PAYMENTS UPON TERMINATION OR CHANGE IN CONTROL

Due to factors such as the timing during the year of an event, the company’s stock price and the executive’s age, any of which can affect the nature and amount of benefits provided upon the events discussed below, actual amounts paid or distributed may vary.

Termination outside of a change in control.  The employment agreements for Messrs. Termeer and Wirth provide for the following payments upon termination by us without cause prior to a change in control:

·a lump sum payment of two times the sum of the annual salary and annual cash incentive;

·continued health, life and disability insurance and other benefits for two years from the date of termination, except to the extent comparable benefits are provided by a new employer; and

·full vesting of all non-performance based rights, options or awards under our equity incentive plans.

Assuming the employment of Messrs. Termeer and Wirth had been terminated by us without cause prior to a change in control on December 31, 2008, they would have been entitled to the following payments:

	Lump Sum Base + Bonus ($)	Benefits ($)	Value of Accelerated Equity Awards ($)(1)	Total(2)
Henri A. Termeer	7,444,500	176,140	10,946,130	18,566,770
Peter Wirth	2,590,000	54,910	2,368,764	5,013,674

(1)Assumes a stock price of $66.37, which was the closing price of our stock on December 31, 2008, the last trading day of the year.

(2)Cash payment amounts are based on the following components:

·base pay using salary as of December 31, 2008 times the multiplier;

·annual cash incentive, calculated by taking the higher of (a) the last cash incentive paid, or (b) the average of the last two cash incentives paid, times the multiplier;

·health benefits, based on COBRA rates as of January 1, 2009;

·life and disability insurance premiums, based on current formula calculations; and

·accrued vacation balances as of December 31, 2008.

Termination due to death or disability.  Under the employment agreements with Messrs. Termeer and Wirth, in the event that their employment is terminated due to death or disability, we will pay all amounts earned, as of the date of termination, under any compensation or benefit plan of the company at the time such payments are due. In addition, under the terms and conditions of all of the named executive officers’ equity awards under our equity incentive plans, all non-performance based rights, options or awards would be fully vested and the named executive officers would have one year from the date of termination to exercise the options unless the options otherwise would expire under their stated terms. Assuming the employment of the named executive officers had been terminated due to death or disability on December 31, 2008, they would have been entitled to the following payments:

	Value of Accelerated Equity Awards Due to Death ($)(1)	Value of Accelerated Equity Awards Due to Disability ($)(1)(2)
Henri A. Termeer	10,946,130	10,946,130
Michael S. Wyzga	2,368,764	1,373,214
Earl M. Collier, Jr.	2,368,764	1,373,214
Sandford D. Smith	2,354,865	1,359,315
Peter Wirth	2,368,764	2,368,764

(1)Assumes a stock price of $66.37, which was the closing price of our stock on December 31, 2008, the last trading day of the year.

(2)RSU awards granted to Messrs. Wyzga, Collier and Smith in 2008 do not provide for vesting as a result of disability.

Termination with retirement eligibility.  Under the terms and conditions of the named executive officers’ equity awards under our equity incentive plans, if their employment terminates for any reason other than for cause after they have reached retirement eligibility (defined as age 60 plus completion of at least five years of service), they will receive full vesting of their outstanding non-performance based stock options and will have three years from the date of termination to exercise the options unless the options would otherwise expire under their stated terms. None of our named executive officers receive any accelerated vesting for RSUs. Messrs. Termeer, Collier and Smith have met the retirement eligibility definition, and assuming these executive officers had terminated their employment on December 31, 2008 other than for cause, they would have been entitled to accelerated vesting of stock options with the following value:

	Value of Accelerated Stock Options ($)(1)
Henri A. Termeer	2,052,550
Earl M. Collier, Jr.	377,664
Sandford D. Smith	363,765

(1)Assumes a stock price of $66.37, which was the closing price of our stock on December 31, 2008, the last trading day of the year.

Executive separation arrangement.  Dr. Georges Gemayel left the company effective June 1, 2008. Under a separation agreement with Dr. Gemayel, he received:

·a lump sum payment of 12 month’s salary;

·50% of his 2008 cash incentive target;

·accelerated vesting of 36,300 options due to vest in May 2009 and an extension of the period of time to exercise his vested options to May 31, 2009; and

·accelerated vesting of two-thirds of unvested RSUs awarded to him in May 2007, totaling 10,000 shares.

The total value of Dr. Gemayel’s separation arrangement was:

Salary + Bonus ($)	Value of Accelerated Equity Awards ($)(1)	Total ($)
748,000	946,372	1,694,372

(1)Value of stock options is based on a stock price of $68.46, which was the closing price of our stock on May 30, 2008. The value of RSUs is based on a stock price of $67.66, the closing price of our stock on June 2, 2008 which was the date of release of the shares.

Termination following a change in control.  Under the employment agreements with Messrs. Termeer and Wirth, upon termination following a change in control of the company, by us other than for cause or as a result of death or disability or by Mr. Termeer or Mr. Wirth for good reason, we must:

·make a lump sum severance payment of three times the sum of the annual salary and annual cash incentive;

·continue life, disability, accident and health insurance coverage for three years, except to the extent comparable benefits are provided by a new employer; and

·in certain circumstances, pay legal costs and relocation expenses associated with the termination.

Under the severance agreements with Messrs. Collier, Smith and Wyzga, upon termination of employment following a change in control of the company, by us without cause or by the named executive officer for good reason, we must:

·make a lump sum severance payment of two times the sum of the annual salary and annual cash incentive;

·continue life, disability, accident and health insurance coverage for two years following the date of termination, except to the extent comparable benefits are provided by a new employer;

·provide outplacement services; and

·in certain circumstances, pay legal costs and relocation expenses associated with such termination.

In addition, under the terms and conditions of the named executive officers’ equity awards under our equity incentive plans, upon a change in control they will receive full vesting of their outstanding stock options and RSUs.

Under the named executive officer’s employment or severance agreements, as applicable, the amounts payable upon a change in control would be reduced to the extent necessary to prevent payments to each named executive officer from exceeding the limit of Section 4999 of the Code applicable to “excess parachute payments” as defined in Section 280G of the Code. Assuming the employment of our named executive officers had been terminated following a change in control of the company by us without cause or by the named executive officer for good reason on December 31, 2008, with no such reduction, they would have been entitled to the following payments:

	Lump Sum Base+Bonus ($)	Benefits ($)	Value of Accelerated Equity Awards ($)(1)	Total(2)
Henri A. Termeer	11,166,750	432,205	10,946,130	22,545,085
Michael S. Wyzga	2,140,000	312,716	2,368,764	4,821,480
Earl M. Collier, Jr.	2,226,000	312,821	2,368,764	4,907,585
Sandford D. Smith	2,090,000	306,817	2,354,865	4,751,682
Peter Wirth	3,885,000	267,250	2,368,764	6,521,014

(1)Assumes a stock price of $66.37, which was the closing price of our stock on December 31, 2008, the last trading day of the year.

(2)Cash payment amounts are based on the following components:

·base pay using salary as of December 31, 2008 times the applicable multiplier;

·annual cash incentive, calculated by taking the higher of (a) the last cash incentive paid, or (b) the average of the last two cash incentives paid, times the applicable multiplier;

·health benefits, based on COBRA rates as of January 1, 2009;

·life, accident and disability insurance premiums, based on current formula calculations;

·accrued vacation balances as of January 1, 2009;

·outplacement services, using the maximum provided for in the agreements;

·relocation services, based on most recent costs paid by us for executive relocation; and

·legal fees, based on an estimate of average attorney rates and hours of estimated services needed.

Under the employment agreements with Messrs. Termeer and Wirth, and the severance agreements with Messrs. Wyzga, Collier and Smith, a “change in control” would be deemed to have occurred if:

(A)          any person, other than Genzyme or our affiliate, becomes the beneficial owner, directly or indirectly, of our securities representing 50% or more of the combined voting power of our then outstanding securities;

(B)           during any period of 24 consecutive months, the individuals who at the beginning of such period constituted our board of directors or any individuals who would be continuing directors cease for any reason to constitute a majority of our board of directors;

(C)           there is consummated a merger, share exchange or consolidation with any other company or the sale of all or substantially all of our assets (each a business combination), other than (i) a business combination that would result in the Genzyme shareholders prior to the business combination continuing to hold a majority of the voting power of the surviving entity or (ii) a business combination effected to implement a recapitalization of the company where no person becomes the beneficial owner of 50% or more of the voting power of our then outstanding securities; or

(D)          our shareholders approve a plan of complete liquidation of the company.

EQUITY PLANS

The following table provides information about shares of our stock that may be issued under our 2001 Equity Incentive Plan, 2004 Equity Incentive Plan, 2007 Director Equity Plan, Directors’ Deferred Compensation Plan and 1999 Employee Stock Purchase Plan, as of December 31, 2008:

Equity Compensation Plan Information

Plan Category	Number of securities to be issued upon exercise of outstanding options, warrants and rights (a)		Weighted-average exercise price of outstanding options, warrants and rights (b)		Number of securities remaining available for future issuance under equity compensation plans (excluding securities reflected in column (a)) (c)
Equity compensation plans approved by security holders	34,849,963	(1)	$	50.64	7,397,221	(2)
Equity compensation plans not approved by security holders	—		—		—
Total	34,849,963		$	50.64	7,397,221

(1)Includes options outstanding assumed in the following acquisitions:

	Acquisition Date	Options Outstanding	Weighted-average exercise price ($)
Ilex	December 2004	63,863	63.54
Focal	June 2001	1,413	310.75
Novazyme	September 2001	1,384	4.09
Biomatrix	December 2000	6,411	505.72
Geltex	December 2000	39,897	13.41

Also includes 16,215 shares in deferred compensation obligations that may be paid out in shares of our common stock.

(2)Includes 509,686 shares that may be issued under our 1999 Employee Stock Purchase Plan plus 89,747 shares reserved under our Directors’ Deferred Compensation Plan.