EASTERN COOPERATIVE ONCOLOGY GROUP (ECOG) PHASE III TRIAL OF RITUXAN MAINTENANCE THERAPY IN INDOLENT NON-HODGKIN’S LYMPHOMA REACHES PRE-SPECIFIED EFFICACY ENDPOINT EARLY

SOUTH SAN FRANCISCO, Calif. & SAN DIEGONOVEMBER 13, 2003

Genentech, Inc. (NYSE:DNA ) Biogen Idec (Nasdaq: BIIB) and Roche have been informed that an Eastern Cooperative Oncology Group (ECOG) Phase III study (E1496) evaluating Rituxan® (rituximab) maintenance therapy has met its pre-specified primary efficacy endpoint early. A pre-planned interim analysis of the study data by an independent ECOG Data Monitoring Committee (DMC) demonstrated a statistically significant improvement in time to treatment failure for patients receiving Rituxan maintenance therapy. Based on this analysis, the DMC has stopped further randomization of patients on this study.

“Indolent NHL is a slow-growing, but incurable disease marked by multiple relapses in which the average patient survives between 6 to 10 years,” said Susan D. Hellmann, M.D., M.P.H., Genentech’s executive vice president, Development and Product Operations, and chief medical officer. “For that reason, the potential ability to keep a patient in remission through maintenance therapy is an important and clinically meaningful benefit to patients. We look forward to seeing the data presented or published in a peer-reviewed forum.”

The Phase III study enrolled previously-untreated (front-line) patients with indolent non-Hodgkin’s lymphoma (NHL). All patients received a maximum of eight doses of induction therapy with cyclophosphophamide, vincristine, and prednisone (CVP). At the time that the study was stopped, 322 patients who responded or had stable disease following induction CVP chemotherapy had been randomized to receive either Rituxan maintenance therapy or no further treatment. Rituxan maintenance therapy consisted of four weekly doses of Rituxan every six months for two years. In this study, time to treatment failure was evaluated as the time from randomization to the first failure, defined as documented disease progression or death.

Rituxan Safety Profile

The majority of patients experience infusion-related symptoms with their first Rituxan infusion. These symptoms include but are not limited to, flu-like fever, chills/rigors, nausea, urticaria, headache, bronchospasm, angioedema and hypotension. These symptoms vary in severity and generally are reversible with medical intervention. In rare instances, severe and fatal infusion-related reactions have occurred, nearly all of which have been associated with the first Rituxan infusion. These events appear as manifestations of an infusion-related complex and include hypoxia, pulmonary infiltrates, acute respiratory distress syndrome, myocardial infarction, ventricular fibrillation, cardiogenic shock and tumor lysis syndrome. Patients who develop clinically significant infusion-related cardiopulmonary events should have their Rituxan infusion discontinued and receive medical treatment.

In rare instances, severe mucocutaneous skin reactions have occurred that may be associated with Rituxan therapy. Many of these reactions have been described as paraneoplastic pemphigus and are known to be associated with various B-cell lymphomas, particularly NHL and CLL. Patients who develop a severe mucocutaneous skin reaction should have Rituxan discontinued and receive appropriate medical treatment including a skin biopsy to guide therapy.

About Rituxan

Rituxan is a therapeutic antibody that binds to a particular protein – the CD20 antigen – on the surface of normal and malignant B-cells. It then recruits the body’s natural defenses to attack and kill the marked B-cells. Stem cells (B-cell progenitors) in bone marrow lack the CD20 antigen, allowing healthy B-cells to regenerate after treatment and return to normal levels within several months.

Rituxan is indicated as a single-agent treatment for relapsed or refractory low-grade or follicular, CD20 positive, B-cell NHL. Rituxan, referred to as MabThera outside the United States, in combination with CHOP chemotherapy, received European approval to treat aggressive NHL in March 2002. More than 300,000 patients have been treated with Rituxan worldwide.

Genentech and Biogen IDEC co-market Rituxan in the United States, Roche markets Rituxan in the rest of the world, except Japan where Rituxan is co-marketed by Roche and Zenyaku Kogyo Co. Ltd.

As a result of the merger, each share of Biogen common stock was converted into the right to receive 1.15 shares of Biogen Idec common stock.

About ECOG

The Eastern Cooperative Oncology Group (ECOG) was established in 1955 as one of the first cooperative groups launched to perform multi-center cancer clinical trials. A cooperative group is a large network of researchers, physicians, and health care professionals at public and private institutions across the country who are members of the group. Funded primarily by the National Cancer Institute (NCI), ECOG has evolved from a five member consortium of institutions on the East Coast to one of the largest clinical cancer research organizations in the United States with almost 6,000 physicians, nurses, pharmacists, statisticians, and clinical research associates (CRAs) from the United States, Canada, and South Africa.

About Genentech

Genentech is a leading biotechnology company that discovers, develops, manufactures and commercializes biotherapeutics for significant unmet medical needs. Sixteen of the currently approved biotechnology products originated from or are based on Genentech science. Genentech manufactures and commercializes 12 biotechnology products in the United States. The company has headquarters in South San Francisco, California and is traded on the New York Stock Exchange under the symbol DNA. For additional information about the company, please visit http://www.gene.com.

About Roche

Headquartered in Basel, Switzerland, Roche is one of the world’s leading innovation-driven healthcare groups. Its core businesses are pharmaceuticals and diagnostics. Roche is number one in the global diagnostics market, the leading supplier of pharmaceuticals for cancer and a leader in virology and transplantation. As a supplier of products and services for the prevention, diagnosis and treatment of disease, the Group contributes on a broad range of fronts to improving people’s health and quality of life. Roche employs roughly 65,000 people in 150 countries. The Group has alliances and R&D; agreements with numerous partners, including majority ownership interests in Genentech and Chugai.

About Biogen Idec

Biogen IDEC creates new standards of care in oncology and immunology. As a global leader in the development, manufacturing, and commercialization of novel therapies, Biogen IDEC transforms scientific discoveries into advances in human healthcare. For product labeling, press releases and additional information about the company, please visit www.biogenidec.com.

For full prescribing information, including Boxed Warnings, please call 650-225-8681. For more information on Rituxan, visit www.rituxan.com.

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Genentech, Inc.
Neil Cohen, 650-225-8681 (Media)
Kathee Littrell, 650-225-1034 (Investor)
or
Biogen Idec
Vince Reardon, 858-431-8801

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