8-K

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) November 16, 2004

ALEXION PHARMACEUTICALS, INC.

(Exact name of registrant as specified in its charter)

Delaware	0-27756	13-3648318
(State or other jurisdiction of incorporation)	(Commission File Number)	(IRS Employer Identification No.)

352 Knotter Drive, Cheshire, CT	06410
(Address of principal executive offices)	(Zip Code)

Registrant’s telephone number, including area code: (203) 272-2596

Not Applicable

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2 below):

¨ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

¨ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

¨ Pre-commencement communications pursuant to Rule 14d-2(b)) under the Exchange Act (17 CFR 240.14d-2(b))

¨ Pre-commencement communications pursuant to Rule 13e-4(g) under the Exchange Act (17 CFR 240.13e-4(c))

Item 8.01 Other Events.

On November 16, 2004, Alexion Pharmaceuticals, Inc., a Delaware corporation (the “Company”), executed a third amendment (the “Third Amendment”) to the Rights Agreement dated as of February 14, 1997, as amended by Amendment No. 1 dated as of September 18, 2000 and Amendment No. 2 dated as of December 12, 2001 (the “Rights Agreement”), by and between the Company and Continental Stock Transfer & Trust Company, as rights agent.

The Third Amendment eliminated all references and provisions relating to “Continuing Directors”, including provisions that previously required a majority of the Continuing Directors to approve the redemption or exchange of the Rights (as defined in the Rights Agreement). “Continuing Director” was defined generally to mean any director who was not an Acquiring Person or representative or nominee of or affiliated or associated with an Acquiring Person and who either was a member of the Board of Directors prior to the Stock Acquisition Date (as those terms are defined in the Rights Agreement) or subsequently became a member and whose election thereto was approved by a majority of the directors who were not Acquiring Persons or representatives or nominees of or affiliated or associated with an Acquiring Person. These provisions that have been deleted are commonly known as “dead hand” provisions. The Third Amendment also eliminated all references to determinations made by Outside Directors (as defined in the Rights Agreement). The Third Amendment is effective immediately.

The original Rights Agreement was filed as Exhibit 1 to the Registration Statement on Form 8-A with the Securities and Exchange Commission (the “SEC”) on February 21, 1997, Amendment No. 1 to the Rights Agreement was filed as Exhibit 10.1 to the Registration Statement on Form 8-A with the SEC on October 6, 2000, and Amendment No. 2 to the Rights Agreement was filed as Exhibit 10.1 to the Registration Statement on Form 8-A with the SEC on February 12, 2002, each of which is hereby incorporated herein by reference.

A copy of the Third Amendment is attached hereto as Exhibit 99.1 and is hereby incorporated herein by reference.

Item 9.01 Financial Statements and Exhibits.

(c) Exhibits.

99.1 Amendment No. 3, dated as of November 16, 2004, to the Rights Agreement by and between the Company and Continental Stock Transfer & Trust Company, as rights agent.

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SIGNATURES

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 hereunto duly authorized.

	ALEXION PHARMACEUTICALS, INC.
Date: November 16, 2004	By:	/s/ Thomas I. H. Dubin
	Name:	Thomas I. H. Dubin
	Title:	Vice President and General Counsel

EX-99.1

Exhibit 99.1

AMENDMENT NO. 3 TO RIGHTS AGREEMENT

This Amendment No. 3 (“Amendment No. 3”) is made as of November 16, 2004 to the Rights Agreement, dated as of February 14, 1997, by and between Alexion Pharmaceuticals, Inc., a Delaware corporation (the “Company”), and Continental Stock Transfer & Trust Company (the “Rights Agent”), as amended by Amendment No. 1 thereto, dated as of September 18, 2000, and Amendment No. 2 thereto, dated as of December 12, 2001 (collectively, the “Rights Agreement”). Capitalized terms not herein defined shall have the meaning ascribed thereto in the Rights Agreement.

WHEREAS, pursuant to Section 26 of the Rights Agreement, the Company may and the Rights Agent shall, if the Company so directs, amend any provision of the Rights Agreement in any respect whatsoever at any time prior to the Stock Acquisition Date;

WHEREAS, the Stock Acquisition Date has not occurred; and

WHEREAS, the Company desires to amend the Rights Agreement to, among other things, remove its so-called “dead hand” provisions which grant only Continuing Directors the right to redeem the Rights;

NOW, THEREFORE, in consideration of the premises and other good and valuable consideration, the parties hereby agree as follows:

1. Amendment to Section 1. Each of Sections 1(k) and 1(s) of the Rights Agreement is hereby deleted in its entirety and replaced with the following: “Intentionally Omitted”.

2. Amendment to Section 11(a)(ii). The first sentence of Section 11(a)(ii) of the Rights Agreement is hereby amended (a) by deleting the clause “who are not Acquiring Persons or representatives, nominees, Affiliates or Associates of an Acquiring Person (the ‘Outside Directors’)” therein and (b) by replacing the defined term “Outside Directors” with “Directors” in the parenthetical clause in Section 11(a)(ii)(A) thereof.

3. Amendment to Section 23.

(a) The first sentence of Section 23(a) of the Rights Agreement is hereby amended by deleting the first parenthetical clause therein, which reads “(which resolution shall, if adopted following the Stock Acquisition Date, be effective only with the concurrence of a majority of the Continuing Directors and only if the Continuing Directors constitute a majority of the number of directors then in office)”, in its entirety.

(b) The first sentence of Section 23(b) of the Rights Agreement is hereby amended (i) by deleting the first parenthetical clause therein, which reads “(with, if required, the concurrence of a majority of the Continuing Directors)”, in its entirety and (ii) by deleting the clause “, with the concurrence of a majority of the Continuing Directors,” in the second parenthetical clause therein.

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4. Amendment to Section 23A(a). The first sentence of Section 23A(a) of the Rights Agreement is hereby amended by deleting the first parenthetical clause therein, which reads “(with the concurrence of a majority of the Continuing Directors and only if the Continuing Directors constitute a majority of the number of Directors then in office)”, in its entirety.

5. Amendment to Section 25. Section 25 of the Rights Agreement is hereby amended by (a) deleting the address “25 Science Park, New Haven, Connecticut 06511” and replacing it with “352 Knotter Drive, Cheshire, Connecticut 06410”, (b) deleting the address “2 Broadway, 19^th Floor, New York, NY 10004” and replacing it with “17 Battery Place, New York, New York 10004” and (c) replacing “Attention: Secretary” with “Attention: General Counsel”.

6. Amendment to Section 26. Section 26 of the Rights Agreement is hereby amended (a) by deleting the first parenthetical clause in the second sentence thereof, which reads “(which resolution shall be effective only with the concurrence of a majority of the Continuing Directors, and only if the Continuing Directors constitute a majority of the number of directors then in office)”, in its entirety and (b) by deleting the parenthetical clause in clause (A) of the proviso to the second sentence thereof, which reads “(with, where required, the concurrence of a majority of the Continuing Directors)”, in its entirety.

7. Amendment to Section 28. Section 28 of the Rights Agreement is hereby amended (a) by deleting the parenthetical clause which reads “(with, where specifically provided for herein, the concurrence of the Continuing Directors or the Outside Directors)” in each instance such parenthetical clause appears in the second and last sentences thereof in its entirety, (b) by replacing the clause “the Outside Directors or the Company” with “the Company” immediately prior to clause (i) of the last sentence thereof and (c) by deleting the clause “, the Continuing Directors or the Outside Directors” in clause (iii) of the last sentence thereof.

8. Amendment to Section 30. The last sentence of Section 30 of the Rights Agreement is hereby amended by deleting the clause “with the concurrence of a majority of the Continuing Directors or the Outside Directors or by the Outside Directors” therein.

9. Amendments to Exhibit C. Exhibit C (the Summary of Rights to Purchase Preferred Stock), to the Rights Agreement is hereby amended (a) by deleting the clause “who are not Acquiring Persons or representatives or nominees of or affiliated or associated with an Acquiring Person” in the first sentence of the sixth paragraph thereof, (b) by deleting the second sentence in the eighth paragraph thereof in its entirety and (c) by deleting the clause “, with the concurrence of a majority of the Continuing Directors,” in the ninth paragraph thereof.

10. No Further Amendment. Except as expressly amended by this Amendment No. 3, the Rights Agreement shall remain in full force and effect as the same was in effect immediately prior to the date of this Amendment No. 3.

11. Counterparts. This Amendment No. 3 may be executed in one or more counterparts, each of which shall be deemed an original and all of which together shall constitute one and the same document.

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IN WITNESS WHEREOF, each of the parties hereto has caused this Amendment No. 3 to be executed in its respective corporate name by one of its duly authorized officers, all as of the date first above written.

ALEXION PHARMACEUTICALS, INC.
By:	/s/    David W. Keiser
Name:	David W. Keiser
Title:	President
CONTINENTAL STOCK TRANSFER & TRUST COMPANY
By:	/s/     Roger Bernhammer
Name:	Roger Bernhammer
Title:	Vice President

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