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

FORM 8-K

Current Report
Pursuant to Section 13 or 15(d) of the
Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): October 5, 2001

Kosan Biosciences Incorporated
(Exact name of registrant as specified in its charter)

Delaware
(State or other jurisdiction of incorporation)

000-31633	94-3217016
(Commission File No.)	(I.R.S. Employer Identification No.)

3832 Bay Center Place
Hayward, California 94545

(address of principal executive offices and zip code)

(Registrant’s telephone number, including area code) (510) 732-8400

TABLE OF CONTENTS

	Item 5. Other Events.
	Item 7. Exhibits
SIGNATURE
INDEX TO EXHIBITS
Certificate of Designation
Press Release, dated as of October 8, 2001.
Rights Agreement, Dated as of October 5, 2001
Form of Rights Certificate

Item 5. Other Events.

     On October 5, 2001, the Board of Directors of Kosan Biosciences Incorporated (the “Company”) approved the adoption of a stockholder Rights Agreement (the “Rights Agreement”). Terms of the Rights Agreement provide for a dividend distribution of one preferred share purchase right (a “Right”) for each outstanding share of common stock, par value $0.001 per share (the “Common Shares”), of the Company. The description and terms of the Rights are set forth in the Rights Agreement, dated as of October 5, 2001, entered into between the Company and Mellon Investor Services LLC, as rights agent (the “Rights Agent”). The dividend is payable on October 29, 2001 (the “Record Date”) to the stockholders of record on that date. Each Right entitles the registered holder to purchase from the Company one one-hundredth of a share of Series A Junior Participating Preferred Stock, par value $0.001 per share (the “Preferred Shares”), at a price of $70.00 per one one-hundredth of a Preferred Share (the “Purchase Price”), subject to adjustment. Each one one-hundredth of a share of Preferred Shares has designations and powers, preferences and rights and the qualifications, limitations and restrictions that make its value approximately equal to the value of a Common Share.

     Initially, the Rights will be evidenced by the stock certificates representing the Common Shares then outstanding, and no separate Right Certificates, as defined below, will be distributed. Until the earlier to occur of (i) the date of a public announcement that a person, entity or group of affiliated or associated persons have acquired beneficial ownership of 20% or more of the outstanding Common Shares (an “Acquiring Person”) or (ii) ten business days (or such later date as may be determined by action of the Board of Directors prior to such time as any person or entity becomes an Acquiring Person) following the commencement of, or announcement of an intention to commence, a tender offer or exchange offer the consummation of which would result in any person or entity becoming an Acquiring Person (the earlier of such dates being called the “Distribution Date”), the Rights will be evidenced, with respect to any of the Common Share certificates outstanding as of the Record Date, by such Common Share certificate with or without a copy of the Summary of Rights, which is included in the Rights Agreement as Exhibit C thereof (the “Summary of Rights”).

     Until the Distribution Date, the Rights will be transferable with and only with the Common Shares. Until the Distribution Date (or earlier redemption or expiration of the Rights), new Common Share certificates issued after the Record Date, upon transfer or new issuance of Common Shares, will contain a notation incorporating the Rights Agreement by reference. Until the Distribution Date (or earlier redemption or expiration of the Rights), the surrender or transfer of any certificates for Common Shares outstanding as of the Record Date, even without such notation or a copy of the Summary of Rights being attached thereto, will also constitute the transfer of the Rights associated with the Common Shares represented by such certificate. As soon as practicable following the Distribution Date, separate certificates evidencing the Rights (“Right Certificates”) will be mailed to holders of record of the Common Shares as of the close of business on the Distribution Date, and such separate Right Certificates alone will evidence the Rights.

     The Rights are not exercisable until the Distribution Date. The Rights will expire on October 29, 2011 (the “Final Expiration Date”), unless the Rights are earlier redeemed or exchanged by the Company, in each case, as described below.

     The Purchase Price payable, and the number of Preferred Shares or other securities or other property, upon exercise of the Rights are subject to adjustment from time to time to prevent dilution (i) in the event of a stock dividend on, or a subdivision, combination or reclassification of, the Preferred Shares, (ii) upon the grant to holders of the Preferred Shares of certain rights or warrants to subscribe for or purchase Preferred Shares at a price, or securities convertible into Preferred Shares with a conversion price, less than the then current market price of the Preferred Shares or (iii) upon the distribution to holders of the Preferred Shares of evidences of indebtedness or assets (excluding regular periodic cash dividends paid out of earnings or retained earnings or dividends payable in Preferred Shares) or of subscription rights or warrants (other than those referred to above). The exercise of Rights for Preferred Shares is at all times subject to the availability of a sufficient number of authorized but unissued Preferred Shares.

     The number of outstanding Rights and the number of one one-hundredths of a Preferred Share issuable upon exercise of each Right are also subject to adjustment in the event of a stock split of the Common Shares or a stock

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dividend on the Common Shares payable in Common Shares or subdivisions, consolidation or combinations of the Common Shares occurring, in any case, prior to the Distribution Date.

     Preferred Shares purchasable upon exercise of the Rights will not be redeemable. Each Preferred Share will be entitled to a minimum preferential quarterly dividend payment of $1.00 but will be entitled to an aggregate dividend of 100 times the dividend declared per Common Share. In the event of liquidation, the holders of the Preferred Shares would be entitled to a minimum preferential liquidation payment of $100 per share, but would be entitled to receive an aggregate payment equal to 100 times the payment made per Common Share. Each Preferred Share will have 100 votes, voting together with the Common Shares. Finally, in the event of any merger, consolidation or other transaction in which Common Shares are exchanged, each Preferred Share will be entitled to receive 100 times the amount of consideration received per Common Share. These rights are protected by customary anti-dilution provisions. Because of the nature of the Preferred Shares’ dividend and liquidation rights, the value of one one-hundredth of a Preferred Share should approximate the value of one Common Share. The Preferred Shares would rank junior to any other series of the Company’s preferred stock.

     In the event that any person or group of affiliated or associated persons becomes an Acquiring Person, proper provision shall be made so that each holder of a Right, other than Rights beneficially owned by the Acquiring Person and its associates and affiliates (which will thereafter be void), will for a 60-day period have the right to receive upon exercise that number of Common Shares having a market value of two times the exercise price of the Right (or, if such number of shares is not and cannot be authorized, the Company may issue Preferred Shares, cash, debt, stock or a combination thereof in exchange for the Rights). This right will terminate 60 days after the date on which the Rights become nonredeemable (as described below), unless there is an injunction or similar obstacle to exercise of the Rights, in which event this right will terminate 60 days after the date on which the Rights again become exercisable.

     Generally, under the Rights Agreement, an “Acquiring Person” shall not be deemed to include (i) the Company, (ii) a subsidiary of the Company, (iii) any employee benefit or compensation plan of the Company or (iv) any entity holding Common Shares for or pursuant to the terms of any such employee benefit or compensation plan.

     In the event that the Company is acquired in a merger or other business combination transaction or 50% or more of its consolidated assets or earning power are sold to an Acquiring Person, its associates or affiliates or certain other persons in which such persons have an interest, proper provision will be made so that each holder of a Right will thereafter have the right to receive, upon the exercise thereof at the then current exercise price of the Right, that number of shares of common stock of the acquiring company which at the time of such transaction will have a market value of two times the exercise price of the Right.

     At any time after an Acquiring Person becomes an Acquiring Person and prior to the acquisition by such Acquiring Person of 50% or more of the outstanding Common Shares, the Board of Directors of the Company may exchange the Rights (other than Rights owned by such person or group which have become void), in whole or in part, at an exchange ratio of one Common Share, or one one-hundredth of a Preferred Share, per Right (or, at the election of the Company, the Company may issue cash, debt, stock or a combination thereof in exchange for the Rights), subject to adjustment. With certain exceptions, no adjustment in the Purchase Price will be required until cumulative adjustments require an adjustment of at least 1% in such Purchase Price. No fractional Preferred Shares will be issued (other than fractions which are integral multiples of the number of one one-hundredths of a Preferred Share issuable upon the exercise of one Right, which may, at the election of the Company, be evidenced by depositary receipts), and in lieu thereof, an adjustment in cash will be made based on the market price of the Preferred Shares on the last trading day prior to the date of exercise.

     At any time prior to the earliest of (i) such time that any person becomes an Acquiring Person or (ii) the Final Expiration Date, the Board of Directors of the Company may redeem the Rights in whole, but not in part, at a price of $0.001 per Right (the “Redemption Price”). Following the expiration of the above periods, the Rights become nonredeemable. Immediately upon any redemption of the Rights, the right to exercise the Rights will terminate, and the only right of the holders of Rights will be to receive the Redemption Price.

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     The terms of the Rights may be amended by the Board of Directors of the Company without the consent of the holders of the Rights, except that from and after such time as the Rights are distributed, no such amendment may adversely affect the interest of the holders of the Rights, excluding the interests of an Acquiring Person.

     Until a Right is exercised, the holder thereof, as such, will have no rights as a stockholder of the Company, including, without limitation, the right to vote or to receive dividends.

     The Rights have certain anti-takeover effects. The Rights will cause substantial dilution to a person or group that attempts to acquire the Company on terms not approved by the Company’s Board of Directors. The Rights should not interfere with any merger or other business combination approved by the Board of Directors since the Rights may be amended to permit such acquisition or redeemed by the Company at $0.001 per Right prior to the earliest of (i) the time that a person or group has acquired beneficial ownership of 20% or more of the Common Shares or (ii) the final expiration date of the rights.

Item 7. Exhibits

4.3	Registrant’s Certificate of Designation of Series A Junior Participating Preferred Stock.
99.1	Press Release, dated as of October 8, 2001, entitled “Kosan Adopts Stockholders Right Plan.”
99.2	Rights Agreement, dated as of October 5, 2001, between Kosan Biosciences Incorporated and Mellon Investor Services LLC.
99.3	Form of Rights Certificate.

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SIGNATURE

     Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

	Kosan Biosciences Incorporated
Dated: October 15, 2001	By:	/s/ SUSAN M. KANAYA
		Susan M. Kanaya Vice President, Finance, Chief Financial Officer and Secretary

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INDEX TO EXHIBITS

4.3	Registrant’s Certificate of Designation of Series A Junior Participating Preferred Stock.
99.1	Press Release, dated as of October 8, 2001, entitled “Kosan Adopts Stockholders Rights Plan.”
99.2	Rights Agreement, dated as of October 5, 2001, between Kosan Biosciences Inc. and Mellon Investor Services LLC.
99.3	Form of Rights Certificate.

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