SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No.__)* Biogen Idec Inc. (Name of Issuer) Common Stock, Par Value $0.0005 (Title of Class of Securities) 09062X103 (CUSIP Number) Marc Weitzen, Esq. Icahn Capital LP 767 Fifth Avenue, 47th Floor New York, New York 10153 (212) 702-4388 (Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications) August 1, 2008 (Date of Event which Requires Filing of this Statement) If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of Section 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box / /. NOTE: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See Rule 13d-7 for other parties to whom copies are to be sent. *The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page. The information required on the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes). SCHEDULE 13D CUSIP No. 09062X103 1 NAME OF REPORTING PERSON High River Limited Partnership 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) / / (b) / / 3 SEC USE ONLY 4 SOURCE OF FUNDS WC 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) / / 6 CITIZENSHIP OR PLACE OF ORGANIZATION Delaware NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: 7 SOLE VOTING POWER 3,502,261 8 SHARED VOTING POWER 0 9 SOLE DISPOSITIVE POWER 3,502,261 10 SHARED DISPOSITIVE POWER 0 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 3,502,261 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES / / 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 1.21% 14 TYPE OF REPORTING PERSON PN SCHEDULE 13D CUSIP No. 09062X103 1 NAME OF REPORTING PERSON Hopper Investments LLC 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) / / (b) / / 3 SEC USE ONLY 4 SOURCE OF FUNDS 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) / / 6 CITIZENSHIP OR PLACE OF ORGANIZATION Delaware NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: 7 SOLE VOTING POWER 0 8 SHARED VOTING POWER 3,502,261 9 SOLE DISPOSITIVE POWER 0 10 SHARED DISPOSITIVE POWER 3,502,261 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 3,502,261 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES / / 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 1.21% 14 TYPE OF REPORTING PERSON OO SCHEDULE 13D CUSIP No. 09062X103 1 NAME OF REPORTING PERSON Barberry Corp. 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) / / (b) / / 3 SEC USE ONLY 4 SOURCE OF FUNDS 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) / / 6 CITIZENSHIP OR PLACE OF ORGANIZATION Delaware NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: 7 SOLE VOTING POWER 0 8 SHARED VOTING POWER 3,502,261 9 SOLE DISPOSITIVE POWER 0 10 SHARED DISPOSITIVE POWER 3,502,261 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 3,502,261 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES / / 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 1.21% 14 TYPE OF REPORTING PERSON CO SCHEDULE 13D CUSIP No. 09062X103 1 NAME OF REPORTING PERSON Icahn Partners Master Fund LP 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) / / (b) / / 3 SEC USE ONLY 4 SOURCE OF FUNDS WC 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) / / 6 CITIZENSHIP OR PLACE OF ORGANIZATION Cayman Islands NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: 7 SOLE VOTING POWER 5,707,871 8 SHARED VOTING POWER 0 9 SOLE DISPOSITIVE POWER 5,707,871 10 SHARED DISPOSITIVE POWER 0 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 5,707,871 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES / / 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 1.97% 14 TYPE OF REPORTING PERSON PN SCHEDULE 13D CUSIP No. 09062X103 1 NAME OF REPORTING PERSON Icahn Partners Master Fund II LP 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) / / (b) / / 3 SEC USE ONLY 4 SOURCE OF FUNDS WC 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) / / 6 CITIZENSHIP OR PLACE OF ORGANIZATION Cayman Islands NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: 7 SOLE VOTING POWER 1,956,501 8 SHARED VOTING POWER 0 9 SOLE DISPOSITIVE POWER 1,956,501 10 SHARED DISPOSITIVE POWER 0 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 1,956,501 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES / / 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.67% 14 TYPE OF REPORTING PERSON PN SCHEDULE 13D CUSIP No. 09062X103 1 NAME OF REPORTING PERSON Icahn Partners Master Fund III LP 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) / / (b) / / 3 SEC USE ONLY 4 SOURCE OF FUNDS WC 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) / / 6 CITIZENSHIP OR PLACE OF ORGANIZATION Cayman Islands NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: 7 SOLE VOTING POWER 743,575 8 SHARED VOTING POWER 0 9 SOLE DISPOSITIVE POWER 743,575 10 SHARED DISPOSITIVE POWER 0 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 743,575 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES / / 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.26% 14 TYPE OF REPORTING PERSON PN SCHEDULE 13D CUSIP No. 09062X103 1 NAME OF REPORTING PERSON Icahn Offshore LP 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) / / (b) / / 3 SEC USE ONLY 4 SOURCE OF FUNDS 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) / / 6 CITIZENSHIP OR PLACE OF ORGANIZATION Delaware NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: 7 SOLE VOTING POWER 0 8 SHARED VOTING POWER 8,407,947 9 SOLE DISPOSITIVE POWER 0 10 SHARED DISPOSITIVE POWER 8,407,947 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 8,407,947 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES / / 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 2.90% 14 TYPE OF REPORTING PERSON PN SCHEDULE 13D CUSIP No. 09062X103 1 NAME OF REPORTING PERSON Icahn Partners LP 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) / / (b) / / 3 SEC USE ONLY 4 SOURCE OF FUNDS WC 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) / / 6 CITIZENSHIP OR PLACE OF ORGANIZATION Delaware NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: 7 SOLE VOTING POWER 5,601,096 8 SHARED VOTING POWER 0 9 SOLE DISPOSITIVE POWER 5,601,096 10 SHARED DISPOSITIVE POWER 0 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 5,601,096 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES / / 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 1.93% 14 TYPE OF REPORTING PERSON PN SCHEDULE 13D CUSIP No. 09062X103 1 NAME OF REPORTING PERSON Icahn Onshore LP 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) / / (b) / / 3 SEC USE ONLY 4 SOURCE OF FUNDS 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) / / 6 CITIZENSHIP OR PLACE OF ORGANIZATION Delaware NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: 7 SOLE VOTING POWER 0 8 SHARED VOTING POWER 5,601,096 9 SOLE DISPOSITIVE POWER 0 10 SHARED DISPOSITIVE POWER 5,601,096 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 5,601,096 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES / / 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 1.93% 14 TYPE OF REPORTING PERSON PN SCHEDULE 13D CUSIP No. 09062X103 1 NAME OF REPORTING PERSON Icahn Capital LP 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) / / (b) / / 3 SEC USE ONLY 4 SOURCE OF FUNDS WC 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) / / 6 CITIZENSHIP OR PLACE OF ORGANIZATION Delaware NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: 7 SOLE VOTING POWER 0 8 SHARED VOTING POWER 14,009,043 9 SOLE DISPOSITIVE POWER 0 10 SHARED DISPOSITIVE POWER 14,009,043 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 14,009,043 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES / / 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 4.83% 14 TYPE OF REPORTING PERSON PN SCHEDULE 13D CUSIP No. 09062X103 1 NAME OF REPORTING PERSON IPH GP LLC 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) / / (b) / / 3 SEC USE ONLY 4 SOURCE OF FUNDS WC 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) / / 6 CITIZENSHIP OR PLACE OF ORGANIZATION Delaware NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: 7 SOLE VOTING POWER 0 8 SHARED VOTING POWER 14,009,043 9 SOLE DISPOSITIVE POWER 0 10 SHARED DISPOSITIVE POWER 14,009,043 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 14,009,043 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES / / 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 4.83% 14 TYPE OF REPORTING PERSON OO SCHEDULE 13D CUSIP No. 09062X103 1 NAME OF REPORTING PERSON Icahn Enterprises Holdings L.P. 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) / / (b) / / 3 SEC USE ONLY 4 SOURCE OF FUNDS WC 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) / / 6 CITIZENSHIP OR PLACE OF ORGANIZATION Delaware NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: 7 SOLE VOTING POWER 0 8 SHARED VOTING POWER 14,009,043 9 SOLE DISPOSITIVE POWER 0 10 SHARED DISPOSITIVE POWER 14,009,043 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 14,009,043 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES / / 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 4.83% 14 TYPE OF REPORTING PERSON PN SCHEDULE 13D CUSIP No. 09062X103 1 NAME OF REPORTING PERSON Icahn Enterprises G.P. Inc. 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) / / (b) / / 3 SEC USE ONLY 4 SOURCE OF FUNDS WC 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) / / 6 CITIZENSHIP OR PLACE OF ORGANIZATION Delaware NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: 7 SOLE VOTING POWER 0 8 SHARED VOTING POWER 14,009,043 9 SOLE DISPOSITIVE POWER 0 10 SHARED DISPOSITIVE POWER 14,009,043 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 14,009,043 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES / / 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 4.83% 14 TYPE OF REPORTING PERSON CO SCHEDULE 13D CUSIP No. 09062X103 1 NAME OF REPORTING PERSON Beckton Corp. 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) / / (b) / / 3 SEC USE ONLY 4 SOURCE OF FUNDS WC 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) / / 6 CITIZENSHIP OR PLACE OF ORGANIZATION Delaware NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: 7 SOLE VOTING POWER 0 8 SHARED VOTING POWER 14,009,043 9 SOLE DISPOSITIVE POWER 0 10 SHARED DISPOSITIVE POWER 14,009,043 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 14,009,043 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES / / 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 4.83% 14 TYPE OF REPORTING PERSON CO SCHEDULE 13D CUSIP No. 09062X103 1 NAME OF REPORTING PERSON Carl C. Icahn 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) / / (b) / / 3 SEC USE ONLY 4 SOURCE OF FUNDS 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) / / 6 CITIZENSHIP OR PLACE OF ORGANIZATION United States of America NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: 7 SOLE VOTING POWER 0 8 SHARED VOTING POWER 17,511,304 9 SOLE DISPOSITIVE POWER 0 10 SHARED DISPOSITIVE POWER 17,511,304 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 17,511,304 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES / / 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 6.03% 14 TYPE OF REPORTING PERSON IN SCHEDULE 13D Item 1. Security and Issuer This statement relates to the Common Stock, par value $0.0005 (the "Shares"), issued by Biogen Idec Inc. (the "Issuer"). The address of the principal executive offices of the Issuer is Biogen Idec Inc., 14 Cambridge Center, Cambridge, Massachusetts 02142. Item 2. Identity and Background The persons filing this statement are High River Limited Partnership ("High River"), Hopper Investments LLC ("Hopper"), Barberry Corp. ("Barberry"), Icahn Partners Master Fund LP ("Icahn Master"), Icahn Partners Master Fund II LP ("Icahn Master II"), Icahn Partners Master Fund III LP ("Icahn Master III"), Icahn Offshore LP ("Icahn Offshore"), Icahn Partners LP ("Icahn Partners"), Icahn Onshore LP ("Icahn Onshore"), Icahn Capital LP ("Icahn Capital"), IPH GP LLC ("IPH"), Icahn Enterprises Holdings L.P. ("Icahn Enterprises Holdings"), Icahn Enterprises G.P. Inc. ("Icahn Enterprises GP"), Beckton Corp. ("Beckton"), and Carl C. Icahn, a citizen of the United States of America (collectively, the "Reporting Persons"). The principal business address of each of (i) High River, Hopper, Barberry, Icahn Offshore, Icahn Partners, Icahn Onshore, Icahn Capital, IPH, Icahn Enterprises Holdings, Icahn Enterprises GP and Beckton is White Plains Plaza, 445 Hamilton Avenue - Suite 1210, White Plains, NY 10601, (ii) Icahn Master, Icahn Master II and Icahn Master III is c/o Walkers SPV Limited, P.O. Box 908GT, 87 Mary Street, George Town, Grand Cayman, Cayman Islands, and (iii) Mr. Icahn is c/o Icahn Associates Corp., 767 Fifth Avenue, 47th Floor, New York, NY 10153. Barberry is the sole member of Hopper, which is the general partner of High River. Icahn Offshore is the general partner of each of Icahn Master, Icahn Master II and Icahn Master III. Icahn Onshore is the general partner of Icahn Partners. Icahn Capital is the general partner of each of Icahn Offshore and Icahn Onshore. Icahn Enterprises Holdings is the sole member of IPH, which is the general partner of Icahn Capital. Beckton is the sole stockholder of Icahn Enterprises GP, which is the general partner of Icahn Enterprises Holdings. Carl C. Icahn is the sole stockholder of each of Barberry and Beckton. As such, Mr. Icahn is in a position indirectly to determine the investment and voting decisions made by each of the Reporting Persons. In addition, Mr. Icahn is the indirect holder of approximately 91% of the outstanding depositary units representing limited partnership interests in Icahn Enterprises L.P. ("Icahn Enterprises"). Icahn Enterprises GP is the general partner of Icahn Enterprises, which is the sole limited partner of Icahn Enterprises Holdings. Each of High River and Barberry is primarily engaged in the business of investing in securities. Hopper is primarily engaged in the business of serving as the general partner of High River. Each of Icahn Master, Icahn Master II, Icahn Master III and Icahn Partners is primarily engaged in the business of investing in securities. Icahn Offshore is primarily engaged in the business of serving as the general partner of each of Icahn Master, Icahn Master II and Icahn Master III. Icahn Onshore is primarily engaged in the business of serving as the general partner of Icahn Partners. Icahn Capital is primarily engaged in the business of serving as the general partner of each of Icahn Offshore and Icahn Onshore. IPH is primarily engaged in the business of serving as the general partner of Icahn Capital. Icahn Enterprises Holdings is primarily engaged in the business of holding direct or indirect interests in various operating businesses. Icahn Enterprises GP is primarily engaged in the business of serving as the general partner of each of Icahn Enterprises and Icahn Enterprises Holdings. Beckton is primarily engaged in the business of holding the capital stock of Icahn Enterprises GP. Carl C. Icahn's present principal occupation or employment is serving as (i) Chief Executive Officer of Icahn Capital LP, a wholly owned subsidiary of Icahn Enterprises, through which Mr. Icahn manages various private investment funds, including Icahn Partners, Icahn Master, Icahn Master II and Icahn Master III, (ii) Chairman of the Board of Icahn Enterprises GP, the general partner of Icahn Enterprises, a New York Stock Exchange listed diversified holding company engaged in a variety of businesses, including investment management, metals, real estate and home fashion, and (iii) Chairman of the Board and a director of Starfire Holding Corporation ("Starfire"), a holding company engaged in the business of investing in and/or holding securities of various entities, and as Chairman of the Board and a director of various of Starfire's subsidiaries. The name, citizenship, present principal occupation or employment and business address of each director and executive officer of the Reporting Persons are set forth in Schedule A attached hereto. None of the Reporting Persons nor any manager or executive officer of the Reporting Persons, has, during the past five years, (a) been convicted in a criminal proceeding (excluding traffic violations or similar misdemeanors), or (b) been a party to a civil proceeding of a judicial or administrative body of competent jurisdiction and as a result of such proceeding was or is subject to a judgment, decree or final order enjoining future violations of, or prohibiting, or mandating activities subject to, Federal or State securities laws or a finding of any violation with respect to such laws. Item 3. Source and Amount of Funds or Other Consideration The Reporting Persons hold, in the aggregate, 17,511,304 Shares. The aggregate purchase price of the Shares purchased by the Reporting Persons collectively was $916,501,219 (including commissions). The source of funding for the purchase of these Shares was the general working capital of the respective purchasers. The Shares are held by the Reporting Persons in margin accounts together with other securities. Such margin accounts may from time to time have debit balances. Part of the purchase price of the Shares purchased by the Reporting Persons was obtained through margin borrowing. The Shares purchased by the Reporting Persons are maintained in margin accounts that include positions in securities in addition to Shares. As of the close of business on August 8, 2008, the indebtedness of (i) High River's margin account was approximately $1,206,212,537, (ii) Icahn Partners' margin account was approximately $221,166,992, (iii) Icahn Master's margin account was approximately $391,343,830, (iv) Icahn Master II's margin account was approximately $104,183,136, and (v) Icahn Master III's margin account was approximately $41,633,836. Item 4. Purpose of Transaction The Reporting Persons recently acquired Shares and further increased their position in the belief that the Shares were undervalued. Representatives of the Reporting Persons have had, and from time to time may seek to continue to have, discussions with representatives of the Issuer to discuss general business issues relating to the Issuer as well as their concerns relating to shareholder value. The Reporting Persons may, from time to time and at any time, acquire additional Shares and/or other equity, debt or other securities (collectively, "Securities") of the Issuer in the open market or otherwise and reserve the right to dispose of any or all of their Securities in the open market or otherwise, at any time and from time to time, and to engage in any hedging or similar transactions with respect to the Securities. Item 5. Interest in Securities of the Issuer (a) The Reporting Persons may be deemed to beneficially own, in the aggregate, 17,511,304 Shares, representing approximately 6.03% of the Issuer's outstanding Shares (based upon the 290,254,475 Shares stated to be outstanding as of July 17, 2008 by the Issuer in the Issuer's Form 10-Q filed with the Securities and Exchange Commission on July 22, 2008 for the quarterly period ended June 30, 2008). (b) High River has sole voting power and sole dispositive power with regard to 3,502,261 Shares. Each of Hopper, Barberry and Carl C. Icahn has shared voting power and shared dispositive power with regard to such Shares. Icahn Master has sole voting power and sole dispositive power with regard to 5,707,871 Shares. Each of Icahn Offshore, Icahn Capital, IPH, Icahn Enterprises Holdings, Icahn Enterprises GP, Beckton and Mr. Icahn has shared voting power and shared dispositive power with regard to such Shares. Icahn Master II has sole voting power and sole dispositive power with regard to 1,956,501 Shares. Each of Icahn Offshore, Icahn Capital, IPH, Icahn Enterprises Holdings, Icahn Enterprises GP, Beckton and Mr. Icahn has shared voting power and shared dispositive power with regard to such Shares. Icahn Master III has sole voting power and sole dispositive power with regard to 743,575 Shares. Each of Icahn Offshore, Icahn Capital, IPH, Icahn Enterprises Holdings, Icahn Enterprises GP, Beckton and Mr. Icahn has shared voting power and shared dispositive power with regard to such Shares. Icahn Partners has sole voting power and sole dispositive power with regard to 5,601,096 Shares. Each of Icahn Onshore, Icahn Capital, IPH, Icahn Enterprises Holdings, Icahn Enterprises GP, Beckton and Mr. Icahn has shared voting power and shared dispositive power with regard to such Shares. Each of Hopper, Barberry and Mr. Icahn, by virtue of their relationships to High River (as disclosed in Item 2), may be deemed to indirectly beneficially own (as that term is defined in Rule 13d-3 under the Act) the Shares which High River directly beneficially owns. Each of Hopper, Barberry and Mr. Icahn disclaims beneficial ownership of such Shares for all other purposes. Each of Icahn Offshore, Icahn Capital, IPH, Icahn Enterprises Holdings, Icahn Enterprises GP, Beckton and Mr. Icahn, by virtue of their relationships to each of Icahn Master, Icahn Master II and Icahn Master III (as disclosed in Item 2), may be deemed to indirectly beneficially own (as that term is defined in Rule 13d-3 under the Act) the Shares which each of Icahn Master, Icahn Master II and Icahn Master III directly beneficially owns. Each of Icahn Offshore, Icahn Capital, IPH, Icahn Enterprises Holdings, Icahn Enterprises GP, Beckton and Mr. Icahn disclaims beneficial ownership of such Shares for all other purposes. Each of Icahn Onshore, Icahn Capital, IPH, Icahn Enterprises Holdings, Icahn Enterprises GP, Beckton and Mr. Icahn, by virtue of their relationships to Icahn Partners (as disclosed in Item 2), may be deemed to indirectly beneficially own (as that term is defined in Rule 13d-3 under the Act) the Shares which Icahn Partners directly beneficially owns. Each of Icahn Onshore, Icahn Capital, IPH, Icahn Enterprises Holdings, Icahn Enterprises GP, Beckton and Mr. Icahn disclaims beneficial ownership of such Shares for all other purposes. (c) The following table sets forth all transactions with respect to Shares effected during the past sixty (60) days by any of the Reporting Persons. Except as otherwise noted below, all such transactions were purchases of Shares effected in the open market, and the table includes commissions paid in per share prices. Name of Date of No. of Shares Purchase Price Per Reporting Person Transaction Purchased Share (U.S.$) ------------------- ------------------- ----------------- ------------------- High River August 1, 2008 180,000 51.50 ------------------- ------------------- ----------------- ------------------- High River August 1, 2008 541,600 51.43 ------------------- ------------------- ----------------- ------------------- High River August 4, 2008 100,000 50.13 ------------------- ------------------- ----------------- ------------------- High River August 5, 2008 4,900 50.08 ------------------- ------------------- ----------------- ------------------- High River August 6, 2008 39,280 50.19 ------------------- ------------------- ----------------- ------------------- High River August 7, 2008 50,000 49.98 ------------------- ------------------- ----------------- ------------------- High River August 8, 2008 7,680 49.97 ------------------- ------------------- ----------------- ------------------- High River August 11, 2008 620 49.98 ------------------- ------------------- ----------------- ------------------- High River August 11, 2008 91,000 50.51 ------------------- ------------------- ----------------- ------------------- Icahn Master August 1, 2008 293,286 51.50 ------------------- ------------------- ----------------- ------------------- Icahn Master August 1, 2008 611,947 51.43 ------------------- ------------------- ----------------- ------------------- Icahn Master August 4, 2008 162,937 50.13 ------------------- ------------------- ----------------- ------------------- Icahn Master August 5, 2008 9,307 50.08 ------------------- ------------------- ----------------- ------------------- Icahn Master August 6, 2008 64,018 50.19 ------------------- ------------------- ----------------- ------------------- Icahn Master August 7, 2008 81,488 49.98 ------------------- ------------------- ------------------------------------- Icahn Master August 8, 2008 12,518 49.97 ------------------- ------------------- ------------------------------------- Icahn Master August 11, 2008 1,010 49.98 ------------------- ------------------- ------------------------------------- Icahn Master August 11, 2008 148,309 50.51 ------------------- ------------------- ------------------------------------- Icahn Master II August 1, 2008 100,573 51.50 ------------------- ------------------- ------------------------------------- Icahn Master II August 1, 2008 322,181 51.43 ------------------- ------------------- ------------------------------------- Icahn Master II August 4, 2008 55,873 50.13 ------------------- ------------------- ------------------------------------- Icahn Master II August 5, 2008 2,419 50.08 ------------------- ------------------- ------------------------------------- Icahn Master II August 6, 2008 21,943 50.19 ------------------- ------------------- ------------------------------------- Icahn Master II August 7, 2008 27,932 49.98 ------------------- ------------------- ------------------------------------- Icahn Master II August 8, 2008 4,291 49.97 ------------------- ------------------- ------------------------------------- Icahn Master II August 11, 2008 346 49.98 ------------------- ------------------- ------------------------------------- Icahn Master II August 11, 2008 50,836 50.51 ------------------- ------------------- ------------------------------------- Icahn Master III August 1, 2008 38,226 51.50 ------------------- ------------------- ------------------------------------- Icahn Master III August 1, 2008 123,869 51.43 ------------------- ------------------- ------------------------------------- Icahn Master III August 4, 2008 21,237 50.13 ------------------- --------------------------------------------------------- Icahn Master III August 5, 2008 861 50.08 ------------------- ------------------- ------------------------------------- Icahn Master III August 6, 2008 8,340 50.19 ------------------- ------------------- ------------------------------------- Icahn Master III August 7, 2008 10,615 49.98 ------------------- ------------------- ------------------------------------- Icahn Master III August 8, 2008 1,629 49.97 ------------------- ------------------- ------------------------------------- Icahn Master III August 11, 2008 132 49.98 ------------------- ------------------- ------------------------------------- Icahn Master III August 11, 2008 19,321 50.51 ------------------- ------------------- ------------------------------------- Icahn Partners August 1, 2008 287,915 51.50 ------------------- ------------------- ------------------------------------- Icahn Partners August 1, 2008 1,108,403 51.43 ------------------- ------------------- ------------------------------------- Icahn Partners August 4, 2008 159,953 50.13 ------------------- ------------------- ------------------------------------- Icahn Partners August 5, 2008 7,013 50.08 ------------------- ------------------- ------------------------------------- Icahn Partners August 6, 2008 62,819 50.19 ------------------- ------------------- -------------------- ---------------- Icahn Partners August 7, 2008 79,965 49.98 ------------------- ------------------- ------------------------------------- Icahn Partners August 8, 2008 12,282 49.97 ------------------- ------------------- ------------------------------------- Icahn Partners August 11, 2008 992 49.98 ------------------- ------------------- ------------------------------------- Icahn Partners August 11, 2008 145,534 50.51 ------------------- ------------------- ------------------------------------- Item 6. Contracts, Arrangements, Understandings or Relationship with Respect to Securities of the Issuer Except as otherwise described herein, there are no contracts, arrangements, understandings or relationships (legal or otherwise) among the persons named in Item 2 and between such persons and any person with respect to any securities of the Issuer, including but not limited to transfer or voting of any of the securities, finder's fees, joint ventures, loan or option arrangements, puts or calls, guarantees of profits, division of profits or loss, or the giving or withholding of proxies. Item 7. Material to be Filed as Exhibits 1 Joint Filing Agreement of the Reporting Persons SIGNATURE After reasonable inquiry and to the best of each of the undersigned knowledge and belief, each of the undersigned certifies that the information set forth in this statement is true, complete and correct. Dated: August 11, 2008 HIGH RIVER LIMITED PARTNERSHIP By: Hopper Investments LLC, general partner By: /s/ Edward Mattner ------------------ Name: Edward Mattner Title: Authorized Signatory HOPPER INVESTMENTS LLC By: /s/ Edward Mattner ------------------ Name: Edward Mattner Title: Authorized Signatory BARBERRY CORP. By: /s/ Edward Mattner ------------------ Name: Edward Mattner Title: Authorized Signatory ICAHN PARTNERS MASTER FUND LP By: /s/ Edward E. Mattner --------------------- Name: Edward E. Mattner Title: Authorized Signatory ICAHN PARTNERS MASTER FUND II LP By: /s/ Edward E. Mattner --------------------- Name: Edward E. Mattner Title: Authorized Signatory ICAHN PARTNERS MASTER FUND III LP By: /s/ Edward E. Mattner --------------------- Name: Edward E. Mattner Title: Authorized Signatory ICAHN OFFSHORE LP By: /s/ Edward E. Mattner --------------------- Name: Edward E. Mattner Title: Authorized Signatory ICAHN PARTNERS LP By: /s/ Edward E. Mattner --------------------- Name: Edward E. Mattner Title: Authorized Signatory ICAHN ONSHORE LP By: /s/ Edward E. Mattner --------------------- Name: Edward E. Mattner Title: Authorized Signatory ICAHN CAPITAL LP By: IPH GP LLC, its general partner By: Icahn Enterprises Holdings L.P., its sole member By: Icahn Enterprises G.P. Inc., its general partner By: /s/ Dominick Ragone ------------------- Name: Dominick Ragone Title: Chief Financial Officer IPH GP LLC By: Icahn Enterprises Holdings L.P., its sole member By: Icahn Enterprises G.P. Inc., its general partner By: /s/ Dominick Ragone ------------------- Name: Dominick Ragone Title: Chief Financial Officer ICAHN ENTERPRISES HOLDINGS L.P. By: Icahn Enterprises G.P. Inc., its general partner By: /s/ Dominick Ragone ------------------- Name: Dominick Ragone Title: Chief Financial Officer ICAHN ENTERPRISES G.P. INC. By: /s/ Dominick Ragone ------------------- Name: Dominick Ragone Title: Chief Financial Officer BECKTON CORP. By: /s/ Edward E. Mattner --------------------- Name: Edward E. Mattner Title: Authorized Signatory /s/ Carl C. Icahn ----------------- CARL C. ICAHN [Signature Page of Schedule 13D - Biogen Idec Inc.] EXHIBIT 1 JOINT FILING AGREEMENT In accordance with Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, as amended, the persons named below agree to the joint filing on behalf of each of them of a statement on Schedule 13D (including amendments thereto) with respect to the Common Stock of Biogen Idec Inc. and further agree that this Joint Filing Agreement be included as an Exhibit to such joint filings. In evidence thereof, the undersigned, being duly authorized, have executed this Joint Filing Agreement this 11th day of August, 2008. HIGH RIVER LIMITED PARTNERSHIP By: Hopper Investments LLC, general partner By: /s/ Edward Mattner --------------------------- Name: Edward Mattner Title: Authorized Signatory HOPPER INVESTMENTS LLC By: /s/ Edward Mattner --------------------------- Name: Edward Mattner Title: Authorized Signatory BARBERRY CORP. By: /s/ Edward Mattner --------------------------- Name: Edward Mattner Title: Authorized Signatory ICAHN PARTNERS MASTER FUND LP By: /s/ Edward E. Mattner ------------------------------ Name: Edward E. Mattner Title: Authorized Signatory ICAHN PARTNERS MASTER FUND II LP By: /s/ Edward E. Mattner ------------------------------ Name: Edward E. Mattner Title: Authorized Signatory ICAHN PARTNERS MASTER FUND III LP By: /s/ Edward E. Mattner ------------------------------ Name: Edward E. Mattner Title: Authorized Signatory ICAHN OFFSHORE LP By: /s/ Edward E. Mattner ------------------------------ Name: Edward E. Mattner Title: Authorized Signatory ICAHN PARTNERS LP By: /s/ Edward E. Mattner ------------------------------ Name: Edward E. Mattner Title: Authorized Signatory ICAHN ONSHORE LP By: /s/ Edward E. Mattner ------------------------------ Name: Edward E. Mattner Title: Authorized Signatory ICAHN CAPITAL LP By: IPH GP LLC, its general partner By: Icahn Enterprises Holdings L.P., its sole member By: Icahn Enterprises G.P. Inc., its general partner By: /s/ Dominick Ragone ---------------------------- Name: Dominick Ragone Title: Chief Financial Officer IPH GP LLC By: Icahn Enterprises Holdings L.P., its sole member By: Icahn Enterprises G.P. Inc., its general partner By: /s/ Dominick Ragone ---------------------------- Name: Dominick Ragone Title: Chief Financial Officer ICAHN ENTERPRISES HOLDINGS L.P. By: Icahn Enterprises G.P. Inc., its general partner By: /s/ Dominick Ragone ---------------------------- Name: Dominick Ragone Title: Chief Financial Officer ICAHN ENTERPRISES G.P. INC. By: /s/ Dominick Ragone ---------------------------- Name: Dominick Ragone Title: Chief Financial Officer BECKTON CORP. By: /s/ Edward E. Mattner ------------------------------ Name: Edward E. Mattner Title: Authorized Signatory /s/ Carl C. Icahn ----------------- CARL C. ICAHN [Signature Page of Joint Filing Agreement to Schedule 13D - Biogen Idec Inc.] SCHEDULE A DIRECTORS AND EXECUTIVE OFFICERS OF THE REPORTING PERSONS The following sets forth the name, position, and principal occupation of each director and executive officer of each of the Reporting Persons. Each such person is a citizen of the United States of America. Except as otherwise indicated, the business address of each director and officer is c/o Icahn Associates Corp., 767 Fifth Avenue, 47th Floor, New York, New York 10153. To the best of the Reporting Persons' knowledge, except as set forth in this statement on Schedule 13D, none of the directors or executive officers of the Reporting Persons own any Shares. HIGH RIVER LIMITED PARTNERSHIP Name Position ---- -------- Hopper Investments LLC General Partner HOPPER INVESTMENTS LLC Name Position ---- -------- Edward E. Mattner Authorized Signatory BARBERRY CORP. Name Position ---- -------- Carl C. Icahn Chairman of the Board; President Jordan Bleznick Vice President/Taxes Edward E. Mattner Vice President; Authorized Signatory Gail Golden Vice President; Authorized Signatory Vincent J. Intrieri Vice President; Authorized Signatory Keith Cozza Secretary; Treasurer Irene March Authorized Signatory ICAHN PARTNERS MASTER FUND LP ICAHN PARTNERS MASTER FUND II LP ICAHN PARTNERS MASTER FUND III LP Name Position ---- -------- Icahn Offshore LP General Partner Carl Icahn Chief Executive Officer Keith A. Meister Managing Director Vincent J. Intrieri Managing Director Rupal Doshi Chief Operating Officer Irene March Chief Financial Officer Edward E. Mattner Authorized Signatory Gail Golden Authorized Signatory Dana Witkin Director of Investor Relations Keith Cozza Chief Compliance Officer Anthony Canova Controller ICAHN PARTNERS LP Name Position ---- -------- Icahn Onshore LP General Partner Carl Icahn Chief Executive Officer Keith A. Meister Managing Director Vincent J. Intrieri Managing Director Rupal Doshi Chief Operating Officer Irene March Chief Financial Officer Edward E. Mattner Authorized Signatory Gail Golden Authorized Signatory Dana Witkin Director of Investor Relations Keith Cozza Chief Compliance Officer Anthony Canova Controller ICAHN ONSHORE LP ICAHN OFFSHORE LP Name Position ---- -------- Icahn Capital LP General Partner Carl Icahn Chief Executive Officer Keith A. Meister Managing Director Vincent J. Intrieri Managing Director Rupal Doshi Chief Operating Officer Irene March Chief Financial Officer Edward E. Mattner Authorized Signatory Gail Golden Authorized Signatory Dana Witkin Director of Investor Relations Keith Cozza Chief Compliance Officer Anthony Canova Controller ICAHN CAPITAL LP Name Position ---- -------- IPH GP LLC General Partner IPH GP LLC Name Position ---- -------- Icahn Enterprises Sole Member Holdings L.P. ICAHN ENTERPRISES HOLDINGS L.P. Name Position ---- -------- Icahn Enterprises General Partner G.P. Inc. ICAHN ENTERPRISES G.P. INC. Name Position ---- -------- Carl C. Icahn Chairman Keith A. Meister Vice Chairman; Principal Executive Officer William A. Leidesdorf Director Jack G. Wasserman Director James L. Nelson Director Vincent J. Intrieri Director Peter K. Shea President Dominick Ragone Chief Financial Officer Andrew Skobe Treasurer John P. Saldarelli Vice President; Secretary Felicia P. Buebel Assistant Secretary Craig Petit Vice President/Taxes BECKTON CORP. Name Position ---- -------- Carl C. Icahn Chairman of the Board; President Jordan Bleznick Vice President/Taxes Edward E. Mattner Authorized Signatory Keith Cozza Secretary; Treasurer