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 29, 2008

Biogen Idec Inc.

(Exact name of registrant as specified in its charter)

Delaware (State or other jurisdiction of incorporation)		0-19311 (Commission file number)		33-0112644 (IRS Employer Identification No.)

14 Cambridge Center, Cambridge, Massachusetts (Address of principal executive offices)		02142 (Zip Code)

Registrant’s telephone number, including area code (617) 679-2000

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):

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

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

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

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

 

 

Item 8.01 Other Events.

          On October 29, 2008, relevant regulatory agencies were notified of a confirmed case of progressive multifocal leukoencephalopathy (PML) in a multiple sclerosis (MS) patient treated with TYSABRI^® in the commercial setting in the United States. Additional information about this case is set forth below.

	•		The diagnosis was made based upon the detection of JC Virus (JCV) DNA in the cerebrospinal fluid (CSF) in the setting of clinical signs, symptoms and magnetic resonance imaging (MRI) findings consistent with the diagnosis of PML.
	•		Background:

	-		Patient has a history of MS and prior disease modifying therapies, including beta-interferons and glatiramer acetate.
	-		Patient had also received prior therapy with methotrexate for a rheumatological condition.
	-		Patient received 14 infusions of TYSABRI monotherapy.
	-		Clinical vigilance led to early identification of signs and symptoms of possible PML and to clinical evaluation which included MRI scanning and CSF testing.
	-		Patient is under the care of patient’s treating physician.

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.

Date: October 29, 2008