William D. Young to Become Chairman of Biogen Idec

-Succeeds Bruce R. Ross Who Will Step Down As Chairman January 1-
-Marijn E. Dekkers to Step Down from Board-

Thursday, December 10, 2009 4:30 pm EST

Dateline:

CAMBRIDGE, Mass.

Public Company Information:

NASDAQ:
BIIB

CAMBRIDGE, Mass.--(BUSINESS WIRE)--Biogen Idec (NASDAQ:BIIB) today announced that William D. Young will become Chairman of the Company’s Board of Directors, effective January 1, 2010. The appointment follows the decision by Bruce R. Ross, 68, the Company’s Chairman since December 2005, to step down as Chairman, effective January 1, 2010. Mr. Ross will complete his current term as Director and will retire from the Board at the Company’s 2010 Annual Shareholder Meeting.

The Board stated, “We are deeply appreciative of all that Bruce Ross has accomplished in his four years as Chairman of Biogen Idec’s Board and his 13 years as Director. During that time, the Company developed and brought to market products that have made a real difference in the lives of many thousands of patients and that have driven tremendous growth at Biogen Idec.”

Mr. Ross said, “It has been a fulfilling experience to serve with such a distinguished group of directors and have had the opportunity to serve the shareholders of such a great company. I am pleased the Board has selected Bill Young as Biogen Idec’s new Chairman. He is an experienced biotechnology and pharmaceutical industry executive with an extensive understanding of Biogen Idec, given his 12 years of service as a Director of the Company.”

The Board also announced today that Marijn E. Dekkers, a Director of the Company since May 2007, is stepping down, effective at year end, before assuming his responsibilities as the new Chief Executive Officer of Bayer HealthCare and a member of the Management Board of Bayer AG on January 1, 2010. Dr. Dekkers most recently was President and Chief Executive Officer of Thermo Fisher Scientific, Inc.

“We are grateful for Marijn Dekkers’ contributions as a Director of Biogen Idec over the past two years, and we wish him well as he assumes his new professional responsibilities,” said Mr. Ross.

Additional Background Information about Mr. Young

From 1999 to October 2009, Mr. Young, 65, was Chairman and Chief Executive Officer for Monogram Biosciences, Inc., a pioneer in the field of personalized medicine. From 1997 to 1999, Mr. Young served as Chief Operating Officer of Genentech, Inc. Mr. Young joined Genentech in 1980 as Director of Manufacturing and Process Sciences and became Vice President in 1983. He was promoted to various positions and, in 1997, became Chief Operating Officer, taking on responsibility for all development, operations and sales and marketing activities. Prior to joining Genentech, Mr. Young was with Eli Lilly & Co. for 14 years. Mr. Young holds a B.S. in Chemical Engineering from Purdue University and a M.B.A. from Indiana University and an Honorary Doctorate in Engineering from Purdue University. Mr. Young began serving as a Director of IDEC Pharmaceuticals in 1997. He is also a Director of Theravance, Inc. Mr. Young was elected to the National Academy of Engineering in 1993 for his contributions to biotechnology.

About Biogen Idec

Biogen Idec creates new standards of care in therapeutic areas with high unmet medical needs. Founded in 1978, Biogen Idec is a global leader in the discovery, development, manufacturing, and commercialization of innovative therapies. Patients in more than 90 countries benefit from Biogen Idec's significant products that address diseases such as lymphoma, multiple sclerosis, and rheumatoid arthritis. For product labeling, press releases and additional information about the company, please visit www.biogenidec.com.

Contact:

Biogen Idec Media:
Naomi Aoki, 617-914-6524
Director, Public Affairs
or
Biogen Idec Investor Relations:
Eric Hoffman, 617-679-2812
Director, Investor Relations