Primary Endpoints Not Met; Collaboration Under Review

Biogen, Inc. (Nasdaq: BGEN) and Celltech Group plc (LSE: CCH; NYSE: CLL) today announced that two Phase III studies of CDP 571 did not meet the primary endpoints for patients with moderate-to-severe Crohn’s disease. The companies will review the scope of their collaboration following additional analysis of the Phase III data and discussions with regulatory authorities.

The agreement on CDP 571 between Biogen and Celltech was signed in April 2002. Biogen’s continued participation is linked to assessment of the results of these Phase III studies.

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, 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

Media Contact:
Amy McKnight
Associate Director, Public Affairs
Biogen, Inc.
(617) 679-2723

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Elizabeth Woo
Director, Investor Relations
Biogen, Inc.
(617) 679-2822