SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                  SCHEDULE 13D

                   Under the Securities Exchange Act of 1934
                               (Amendment No.5)*

                                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)

                                 June 21, 2011
            (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
      1,645,051

8   SHARED  VOTING  POWER
      0

9   SOLE  DISPOSITIVE  POWER
      1,645,051

10  SHARED  DISPOSITIVE  POWER
      0

11  AGGREGATE  AMOUNT  BENEFICIALLY  OWNED  BY  EACH  REPORTING  PERSON
      1,645,051

12  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES    / /

13  PERCENT  OF  CLASS  REPRESENTED  BY  AMOUNT  IN  ROW  (11)
      0.68%

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
      1,645,051

9   SOLE  DISPOSITIVE  POWER
      0

10  SHARED  DISPOSITIVE  POWER
      1,645,051

11  AGGREGATE  AMOUNT  BENEFICIALLY  OWNED  BY  EACH  REPORTING  PERSON
      1,645,051

12  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES    / /

13  PERCENT  OF  CLASS  REPRESENTED  BY  AMOUNT  IN  ROW  (11)
      0.68%

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
      1,645,051

9   SOLE  DISPOSITIVE  POWER
      0

10  SHARED  DISPOSITIVE  POWER
      1,645,051

11  AGGREGATE  AMOUNT  BENEFICIALLY  OWNED  BY  EACH  REPORTING  PERSON
      1,645,051

12  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES    / /

13  PERCENT  OF  CLASS  REPRESENTED  BY  AMOUNT  IN  ROW  (11)
      0.68%

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
      2,721,425

8   SHARED  VOTING  POWER
      0

9   SOLE  DISPOSITIVE  POWER
      2,721,425

10  SHARED  DISPOSITIVE  POWER
      0

11  AGGREGATE  AMOUNT  BENEFICIALLY  OWNED  BY  EACH  REPORTING  PERSON
      2,721,425

12  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES    / /

13  PERCENT  OF  CLASS  REPRESENTED  BY  AMOUNT  IN  ROW  (11)
      1.13%

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
      932,988

8   SHARED  VOTING  POWER
      0

9   SOLE  DISPOSITIVE  POWER
      932,988

10  SHARED  DISPOSITIVE  POWER
      0

11  AGGREGATE  AMOUNT  BENEFICIALLY  OWNED  BY  EACH  REPORTING  PERSON
      932,988

12  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES    / /

13  PERCENT  OF  CLASS  REPRESENTED  BY  AMOUNT  IN  ROW  (11)
      0.39%

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
      405,946

8   SHARED  VOTING  POWER
      0

9   SOLE  DISPOSITIVE  POWER
      405,946

10  SHARED  DISPOSITIVE  POWER
      0

11  AGGREGATE  AMOUNT  BENEFICIALLY  OWNED  BY  EACH  REPORTING  PERSON
      405,946

12  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES    / /

13  PERCENT  OF  CLASS  REPRESENTED  BY  AMOUNT  IN  ROW  (11)
      0.17%

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
      4,060,359

9   SOLE  DISPOSITIVE  POWER
      0

10  SHARED  DISPOSITIVE  POWER
      4,060,359

11  AGGREGATE  AMOUNT  BENEFICIALLY  OWNED  BY  EACH  REPORTING  PERSON
      4,060,359

12  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES    / /

13  PERCENT  OF  CLASS  REPRESENTED  BY  AMOUNT  IN  ROW  (11)
      1.68%

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
      2,519,846

8   SHARED  VOTING  POWER
      0

9   SOLE  DISPOSITIVE  POWER
      2,519,846

10  SHARED  DISPOSITIVE  POWER
      0

11  AGGREGATE  AMOUNT  BENEFICIALLY  OWNED  BY  EACH  REPORTING  PERSON
      2,519,846

12  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES    / /

13  PERCENT  OF  CLASS  REPRESENTED  BY  AMOUNT  IN  ROW  (11)
      1.04%

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
      2,519,846

9   SOLE  DISPOSITIVE  POWER
      0

10  SHARED  DISPOSITIVE  POWER
      2,519,846

11  AGGREGATE  AMOUNT  BENEFICIALLY  OWNED  BY  EACH  REPORTING  PERSON
      2,519,846

12  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES    / /

13  PERCENT  OF  CLASS  REPRESENTED  BY  AMOUNT  IN  ROW  (11)
      1.04%

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
      6,580,205

9   SOLE  DISPOSITIVE  POWER
      0

10  SHARED  DISPOSITIVE  POWER
      6,580,205

11  AGGREGATE  AMOUNT  BENEFICIALLY  OWNED  BY  EACH  REPORTING  PERSON
      6,580,205

12  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES    / /

13  PERCENT  OF  CLASS  REPRESENTED  BY  AMOUNT  IN  ROW  (11)
      2.72%

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
      6,580,205

9   SOLE  DISPOSITIVE  POWER
      0

10  SHARED  DISPOSITIVE  POWER
      6,580,205

11  AGGREGATE  AMOUNT  BENEFICIALLY  OWNED  BY  EACH  REPORTING  PERSON
      6,580,205

12  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES    / /

13  PERCENT  OF  CLASS  REPRESENTED  BY  AMOUNT  IN  ROW  (11)
      2.72%

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
      6,580,205

9   SOLE  DISPOSITIVE  POWER
      0

10  SHARED  DISPOSITIVE  POWER
      6,580,205

11  AGGREGATE  AMOUNT  BENEFICIALLY  OWNED  BY  EACH  REPORTING  PERSON
      6,580,205

12  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES    / /

13  PERCENT  OF  CLASS  REPRESENTED  BY  AMOUNT  IN  ROW  (11)
      2.72%

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
      6,580,205

9   SOLE  DISPOSITIVE  POWER
      0

10  SHARED  DISPOSITIVE  POWER
      6,580,205

11  AGGREGATE  AMOUNT  BENEFICIALLY  OWNED  BY  EACH  REPORTING  PERSON
      6,580,205

12  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES    / /

13  PERCENT  OF  CLASS  REPRESENTED  BY  AMOUNT  IN  ROW  (11)
      2.72%

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
      6,580,205

9   SOLE  DISPOSITIVE  POWER
      0

10  SHARED  DISPOSITIVE  POWER
      6,580,205

11  AGGREGATE  AMOUNT  BENEFICIALLY  OWNED  BY  EACH  REPORTING  PERSON
      6,580,205

12  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES    / /

13  PERCENT  OF  CLASS  REPRESENTED  BY  AMOUNT  IN  ROW  (11)
      2.72%

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
      8,225,256

9   SOLE  DISPOSITIVE  POWER
      0

10  SHARED  DISPOSITIVE  POWER
      8,225,256

11  AGGREGATE  AMOUNT  BENEFICIALLY  OWNED  BY  EACH  REPORTING  PERSON
      8,225,256

12  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES    / /

13  PERCENT  OF  CLASS  REPRESENTED  BY  AMOUNT  IN  ROW  (11)
      3.40%

14  TYPE  OF  REPORTING  PERSON
      IN



                                  SCHEDULE 13D

Item 1. Security and Issuer

     The  Schedule  13D  filed  with  the  Securities and Exchange Commission on
August  11,  2008  by  the  Reporting Persons (together with the amendments, the
"Schedule  13D")  with  respect to the shares of Common Stock, par value $0.0005
(the  "Shares"),  issued  by  Biogen  Idec  Inc.  (the  "Issuer"), as amended by
amendment  number  one to the Schedule 13D filed on February 6, 2009, as amended
by  amendment  number  two  to  the  Schedule  13D filed on January 28, 2010, as
amended  by  amendment number three to the Schedule 13D filed on March 20, 2010,
and  as  amended  by  amendment number four to the Schedule 13D filed on May 20,
2011,  is hereby further amended to furnish the additional information set forth
herein.  This fifth amendment to Schedule 13D reports that the Reporting Persons
ceased  to  be the beneficial owner of more than five percent (5%) of the Shares
on  June  21,  2011.  All  capitalized  terms contained herein but not otherwise
defined  shall  have  the  meanings  ascribed to such terms in the Schedule 13D.

Item 3. Source and Amount of Funds or Other Consideration

     Item  3  of  the  Schedule  13D  is  hereby  amended by replacing it in its
entirety  with  the  following:

     The  Reporting  Persons  hold,  in  the  aggregate,  8,225,256 Shares. The
aggregate  purchase price of the Shares currently owned by the Reporting Persons
collectively was $402,586,237 (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.

Item 5. Interest in Securities of the Issuer

     Item  5  of  the  Schedule  13D  is  hereby  amended by replacing it in its
entirety  with  the  following:

     (a)  The  Reporting  Persons  may  be  deemed  to  beneficially own, in the
aggregate,  8,225,256  Shares, representing approximately 3.40% of the Issuer's
outstanding  Shares  (based upon the 241,632,189 Shares stated to be outstanding
as  of  April  18,  2011  by the Issuer in the Issuer's Form 10-Q filed with the
Securities  and  Exchange  Commission  for  the quarterly period ended March 31,
2011).

     (b) High River has sole voting power and sole dispositive power with regard
to  1,645,051  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 2,721,425
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 932,988 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 405,946 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  2,519,846  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 sales of Shares effected in
the  open  market,  and the table includes commissions paid in per share prices.

Name of                   Date                 No. of         Sales
Reporting                 of                   Shares         Proceeds Per
Person                    Transaction          Sold           Shares (US$)
---------                 -----------          ------         ------------
High River                 04/27/2011        100,000.00           99.60
High River                 04/28/2011        128,573.00           99.03
High River                 04/29/2011         51,313.00           98.94
High River                 05/02/2011         53,929.00           98.78
High River                 05/03/2011          6,593.00           98.74
High River                 05/09/2011         32,592.00           98.45
High River                 05/10/2011          3,000.00           97.99
High River                 05/12/2011         24,000.00           97.95
High River                 05/13/2011         13,549.00           98.04
High River                 05/17/2011          7,146.00           97.89
High River                 05/18/2011          8,064.00           97.89
High River                 05/19/2011          3,851.00           98.30
High River                 05/20/2011         96,638.00           97.88
High River                 06/20/2011        200,000.00           98.70
High River                 06/21/2011        275,752.00           99.55
High River                 06/22/2011        565,000.00           99.52

Icahn Partners             04/29/2011          2,378.00           98.94
Icahn Partners             05/02/2011        103,090.00           98.78
Icahn Partners             05/03/2011         10,763.00           98.74
Icahn Partners             05/09/2011         53,209.00           98.45
Icahn Partners             05/10/2011          4,898.00           97.99
Icahn Partners             05/12/2011         39,182.00           97.95
Icahn Partners             05/13/2011         22,120.00           98.04
Icahn Partners             05/17/2011         11,668.00           97.89
Icahn Partners             05/18/2011         13,164.00           97.89
Icahn Partners             05/19/2011          6,287.00           98.30
Icahn Partners             05/20/2011        151,617.00           97.88
Icahn Partners             06/20/2011        306,782.00           98.70
Icahn Partners             06/21/2011        422,390.00           99.55
Icahn Partners             06/22/2011        865,453.00           99.52

Icahn Master               04/27/2011        400,000.00           99.60
Icahn Master               04/28/2011        492,942.00           99.03
Icahn Master               04/29/2011        150,474.00           98.94
Icahn Master               05/02/2011         65,690.00           98.78
Icahn Master               05/03/2011         11,620.00           98.74
Icahn Master               05/09/2011         57,444.00           98.45
Icahn Master               05/10/2011          5,287.00           97.99
Icahn Master               05/12/2011         42,300.00           97.95
Icahn Master               05/13/2011         23,882.00           98.04
Icahn Master               05/17/2011         12,595.00           97.89
Icahn Master               05/18/2011         14,212.00           97.89
Icahn Master               05/19/2011          6,787.00           98.30
Icahn Master               05/20/2011        163,683.00           97.88
Icahn Master               06/20/2011        329,602.00           98.70
Icahn Master               06/21/2011        456,179.00           99.55
Icahn Master               06/22/2011        934,685.00           99.52

Icahn Master II            04/28/2011         21,349.00           99.03
Icahn Master II            04/29/2011         52,402.00           98.94
Icahn Master II            05/02/2011         46,936.00           98.78
Icahn Master II            05/03/2011          3,989.00           98.74
Icahn Master II            05/09/2011         19,714.00           98.45
Icahn Master II            05/10/2011          1,815.00           97.99
Icahn Master II            05/12/2011         14,518.00           97.95
Icahn Master II            05/13/2011          8,196.00           98.04
Icahn Master II            05/17/2011          4,322.00           97.89
Icahn Master II            05/18/2011          4,878.00           97.89
Icahn Master II            05/19/2011          2,329.00           98.30
Icahn Master II            05/20/2011         56,176.00           97.88
Icahn Master II            06/20/2011        114,635.00           98.70
Icahn Master II            06/21/2011        156,392.00           99.55
Icahn Master II            06/22/2011        320,438.00           99.52

Icahn Master III           05/20/2011         15,076.00           97.88
Icahn Master III           06/20/2011         48,981.00           98.70
Icahn Master III           06/21/2011         68,047.00           99.55
Icahn Master III           06/22/2011        139,424.00           99.52

     (d) Not applicable.

     (e)  On  June  21,  2011, the Reporting Persons ceased to be the beneficial
owner  of  more  than  five  percent  of  the  Shares.



                                   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: June 22, 2011

HIGH  RIVER  LIMITED  PARTNERSHIP
HOPPER  INVESTMENTS  LLC
BARBERRY  CORP.
ICAHN  PARTNERS  MASTER  FUND  LP
ICAHN  PARTNERS  MASTER  FUND  II  LP
ICAHN  PARTNERS  MASTER  FUND  III  LP
ICAHN  OFFSHORE  LP
ICAHN  PARTNERS  LP
ICAHN  ONSHORE  LP

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, Amendment No. 5 - Biogen Idec Inc.]