CELLTECH AND BIOGEN ANNOUNCE WORLD-WIDE COLLABORATION, TO DEVELOP AND COMMERCIALISE PHASE III CROHN’S DISEASE PRODUCT

Companies Also to Explore CDP 571 in Psoriasis Patients

Celltech Group Plc (LSE: CCH; NYSE: CLL) and Biogen, Inc. (NASDAQ: BGEN) today announced a collaboration for the research, development, manufacturing and commercialization of CDP 571, Celltech’s humanized anti-TNFα antibody product, which is in Phase III development as a treatment for Crohn’s disease.

Key terms of the collaboration are as follows:

  • Celltech and Biogen will share ongoing research, development and registration costs and intend to explore the use of CDP 571 in additional inflammatory conditions, such as psoriasis.
  • Manufacturing of CDP 571 will be transferred following its launch from the current supplier to Biogen’s state-of-the-art 90,000 litre production facility in Research Triangle Park, North Carolina, which will substantially reduce the cost of manufacturing the product.
  • Celltech and Biogen will each establish specialist salesforces to jointly promote CDP 571 in the US and major European territories, except in Italy where Celltech will have sole commercial rights. The parties will share profits equally in these territories.
  • The agreement provides for Celltech to withdraw from joint promotion of CDP 571 should it successfully gain registration for its third-generation anti-TNFα antibody fragment, CDP 870, in Crohn’s disease. In this scenario, Celltech retains its share of future profits from CDP 571.
  • The collaboration also provides Biogen, at its discretion, with the right to withdraw from elements of the agreement if certain critical milestones are not reached.

    CDP 571 is a fully humanised anti-TNFα antibody, which is being developed as a potential treatment for Crohn’s disease and other inflammatory disorders. CDP 571 is currently being studied in two large international Phase III studies in Crohn’s disease, results from which are expected in mid-2002. In the U.S., CDP 571 has Orphan Drug status. It also has FDA Fast Track Designation for steroid withdrawal in steroid dependent patients.

    Dr Peter Fellner, Chief Executive Officer of Celltech, commented: “This agreement provides exceptional advantages to both companies. Access to Biogen’s outstanding mammalian cell-based production capabilities will substantially reduce the manufacturing cost of this product. The collaboration also enables Celltech to benefit from Biogen’s great experience in commercializing specialized biologic products. As a result, this collaboration may extend the in-market life of CDP 571.”

    Jim Mullen, Chief Executive of Biogen, commented: “Biogen has known Celltech for more than a decade and we have great respect for the company’s science and its management. With today’s agreement, Biogen acquires access to a Phase III product that increases the company’s synergies in our portfolio of treatment options for autoimmune disorders. The collaboration will also allow Biogen to further develop expertise that will prove commercially valuable to ANTEGREN, now in Phase III clinical trials for Crohn’s disease. And with our psoriasis product, AMEVIVE, now eight months into the approval process, the potential application of CDP 571 in this indication further confirms the strategic fit of this collaboration.”

    Contacts:

    Celltech

    Dr. Peter Fellner, Chief Executive Officer(44) (0) 1753 534655
    Peter Allen, Chief Financial Officer
    Richard Bungay, Director of Corporate Communications

    Jon Coles, Brunswick (London)(44) (0) 207 404 5959
    Katharine Sharkey
    Cindy Leggett-Flynn, Brunswick (New York) (1) (212) 333 3810

    Biogen, Inc.

    Media Contacts:
    Gregory Peterson, Vice President, Public Affairs(1) (617) 914 6524

    Investment Community Contact:
    Elizabeth Woo, Director, Investor Relations(1) (617) 679 2812

    Celltech Group plc (LSE: CCH; NYSE: CLL) is one of Europe’s largest biotechnology companies, with seven products in Phase II or Phase III development and a profitable, cash-generative pharmaceutical business. Celltech’s research and development activities are focused on treatments for immune and inflammatory disorders and cancer, and encompass both antibody and small molecule approaches. Celltech has a leading position in antibody therapeutics, including its proprietary antibody fragment microbial expression system, which is being employed in four of its current development programmes. More information about Celltech can be found at www.celltechgroup.com.

    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 (R) (Interferon beta-1a) for the treatment of relapsing forms of multiple sclerosis, (Please see full prescribing information at http://www.avonex.com), and from the world-wide 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.

    In addition to historical information, this press release contains forward-looking statements within the meaning of the “safe harbor” provisions of the Private Securities Litigation Reform Act of 1995. Reference is made in particular to forward looking statements regarding the Companies’ expectations as to the timing of results of Phase III clinical trials of CDP 571, the potential and possible efficacy of CDP 571, and the substantial reduction in manufacturing costs for CDP 571. These forward looking statements are based on the Companies current beliefs and expectations as to such future outcomes and involves risks and uncertainties that could cause actual results to differ materially from those reflected in the forward-looking statements. Drug development involves a high degree of risk. Success in early stage clinical trials does not ensure that later stage or larger scale clinical trials will be successful. Factors which could cause actual results to differ materially from the Companies current expectations include the risk that the Companies will encounter one or more technical hurdles associated with new drug development, the risk that the product may not show therapeutic effect or an acceptable safety profile in subsequent trials or may not meet applicable regulatory standards, or that problems or delays may arise during clinical trials or in the course of the development, testing or manufacturing of the product, including the transfer of the manufacturing to a new facility, as well as the other risks and uncertainties described from time to time in the Companies periodic reports filed with the Securities and Exchange Commission.

    Notes for Editors

    CDP 571
    CDP 571 belongs to a new therapeutic class of medicines that inhibit tumor necrosis factor alpha (TNF-alpha), a key mediator in a number of autoimmune and inflammatory diseases, including rheumatoid arthritis and Crohn’s disease. CDP 571 is a second-generation, humanised antibody, which binds with high affinity to TNF-alpha.

    In a previously reported Phase IIb study, involving 169 patients with moderate/severe Crohn’s disease, CDP 571 demonstrated reductions in CDAI (Crohn’s Disease Activity Index) scores. 54% of patients treated with 10 mg/kg of CDP 571 achieved a clinical response (defined as a reduction of 70 points or more in the CDAI score) at two weeks (placebo response rate: 26%). A further phase II study to look at the ability of CDP 571 to enable patients to discontinue steroid treatment without disease flare was carried out. In this study, 71 patients who were dependent upon steroids to maintain disease remission were treated with CDP 571 or placebo, and their steroids were discontinued. 46% of CDP 571 treated patients did not experience disease flare at week 16 compared with placebo (22%).

    CDP 571 was generally well tolerated by patients. The most common adverse events seen in the Phase II Crohn’s disease clinical trials were headache, abdominal pain, infection and nausea. These adverse events occurred equally in both placebo and drug treated patients. Certain adverse events occurring at low frequency such as rash were seen more commonly with CDP 571 treatment compared to placebo. Some patients experienced adverse events related to infusion, one of which was classified as serious.

    CDP 571 is currently being assessed as a treatment for Crohn’s disease in two large Phase III trials. The first of these studies, undertaken over 35 weeks, is being carried out in 273 steroid-dependent patients, and will assess the ability of CDP 571 to enable safe withdrawal of steroids from these patients whilst maintaining disease remission. A second larger study, involving 397 patients, is designed to confirm data from the Phase IIb study, which assessed the effectiveness of CDP 571 to maintain disease remission over an extended timeframe (28 weeks). Recruitment has been completed in both of these studies, with results expected in mid-2002.

    Crohn’s disease
    Crohn’s disease is a chronic, inflammatory disease of the gastrointestinal tract. Symptoms associated with Crohn’s disease include diarrhoea, abdominal pain and fever, and can also include fissures, fistulas and abscesses. Loss of appetite and subsequent weight loss also may occur. In addition, certain drugs used to treat the disease may cause side effects, such as high-dose corticosteroid therapy, which can predispose patients to infections, bone thinning (osteoporosis), and fractures. Crohn’s disease causes considerable morbidity and up to 25% of patients with active disease may require hospital treatment each year. Approximately 400,000 patients are estimated to have Crohn’s Disease in the US and EU.

    Crohn’s disease is named after Burrill B. Crohn, the first name in a three-author landmark paper published in 1932, which described the disease.

    Crohn’s Disease Activity Index (CDAI)
    The CDAI is the generally accepted and validated composite measure for Crohn’s disease clinical trials. It is an assessment of eight different measures, including:

  • Abdominal pain rating
  • Symptoms related to Crohn’s disease, such as arthritis, uveitis, fistula and febrile (fever) episodes
  • Hematocrit (red blood cell count) and biochemical blood markers of chronic inflammation
  • Body weight

    A reduction following treatment in the CDAI index of 70 points or more is generally viewed as a clinically significant response, and a CDAI score of 150 or below is generally viewed as representing disease remission.