Biogen, Inc. (NASDAQ/BGEN) today announced that James L. Vincent is retiring as Chairman of the Board and as a Director of Biogen. The Board has elected James C. Mullen as Chairman. He will continue in his role as Chief Executive Officer.

The Board stated, “We are grateful for the many significant contributions made by Jim Vincent during his 16 years of leadership at Biogen. We are confident that Jim Mullen’s leadership skills and breadth of experience will drive Biogen to the next level as a multi-product, global biotechnology company.”

Mr. Mullen’s election as Chairman completes a long-standing, planned transition under which Mr. Mullen succeeded Mr. Vincent as Chief Executive Officer in June 2000. In connection with this transition, Mr. Vincent will receive severance and other benefits consistent with his 1996 employment agreement.

About Biogen

Biogen, Inc., winner of the U.S. National Medal of Technology, is a biotechnology
company principally engaged in discovering and developing drugs for human healthcare through genetic engineering. Headquartered in Cambridge, MA, the Company’s revenues are generated from U.S. and European sales of AVONEX® (Interferon beta-1a) for treatment of relapsing forms of multiple sclerosis, (Please see full prescribing information at http://www.avonex.com.), and from the worldwide sales by licensees of a number of products, including alpha interferon and hepatitis B vaccines and diagnostic products. Biogen’s research and development activities are focused on novel products to treat inflammatory and autoimmune diseases, neurological diseases, cancer, fibrosis and congestive heart failure. The Company maintains active clinical research programs in protein therapeutics, small molecules, genomics and gene therapy. For copies of press releases and additional information about the Company, please consult Biogen’s homepage on the World Wide Web at http://www.biogen.com.

Media Contact:
Tim Hunt
Director, Public Affairs
Biogen, Inc.
Tel: (617) 679-4996

Investment Community Contact:
Elizabeth Woo
Director, Investor Relations
Biogen, Inc.
Tel: (617) 679-2822