Wednesday, Nov 26, 1997

First New Drug for Non-Hodgkin's Lymphoma in Decade Receives FDA Clearance for Marketing

First U.S. Monoclonal Antibody For Therapeutic Use in Cancer

San Diego and South San Francisco, Calif. -- November 26, 1997 --

IDEC Pharmaceuticals Corporation (NASDAQ: IDPH) and Genentech, Inc. (NYSE: GNE) today announced that RITUXAN™ (Rituximab) has been cleared for marketing by the U.S. Food and Drug Administration (FDA). Rituxan, previously known as the C2B8 antibody, is a single-agent monoclonal antibody therapy for the treatment of relapsed or refractory low-grade or follicular, CD20-positive B-cell non-Hodgkin's lymphoma.

In the pivotal trial conducted at 31 U.S. sites, Rituxan, when used alone, showed a 48 percent overall response rate. Eighty of 166 patients experienced tumor shrinkage of 50 percent or greater following four weekly infusions. The median duration of response is projected to be 10-12 months. Patients continue to be monitored. These results corroborated those seen in earlier studies.

In clinical trials, the most common adverse events associated with Rituxan were infusion-related, consisting mainly of mild to moderate flu-like symptoms (e.g., fever, chills, rigors) that occurred in the majority of patients during the first infusion. Other events which occurred with less frequency included nausea, rashes, fatigue and headache. More serious events included hypotension, wheezing, sensation of tongue or throat swelling and recurrence of cardiac events in patients with a history of angina or arrhythmia. These symptoms were usually limited in duration to the period of infusion and decreased with subsequent infusions.

RITUXAN™ (Rituximab) is the first new single-agent therapy in 10 years for non-Hodgkin's lymphoma and the first monoclonal antibody licensed for the treatment of cancer in the United States. Rituxan also represents the first marketed monoclonal antibody product for Genentech's BioOncology initiative, and is the first marketed product for IDEC. It is expected to be commercially available for use within approximately three weeks.

"Rituxan represents an important turning point in the treatment of lymphoma," said Myron Czuczman, M.D., Assistant Professor of Medicine, Roswell Park Cancer Institute, Buffalo, New York, and a key investigator. "Although it is not a cure, we finally have a cancer agent that can be effective with less serious side effects than with conventional chemotherapy. Treatment can also be completed in 22 days, unlike the typical four- to six-month chemotherapy regimens. This is exciting news, especially for elderly patients and relapsed patients who have failed at least one standard treatment regimen."

"We are very pleased that Rituxan has been cleared for marketing as it marks an important milestone in the treatment of cancer," said William H. Rastetter, Ph.D., IDEC Pharmaceuticals' chairman, president and chief executive officer. "IDEC and Genentech are committed to continued exploration of further uses of Rituxan as a first line therapy for low-grade lymphoma, in combination with other anti-cancer treatments for lymphoma, and in intermediate- and high-grade lymphomas."

"The licensing of Rituxan affirms our strategy of pairing Genentech's existing strengths with our partners' development resources in order to bring important new products to market," said Arthur D. Levinson, Ph.D., Genentech's president and chief executive officer. "Rituxan is the first to be promoted in a series of innovative biotherapeutic cancer agents that will follow from Genentech's pipeline. It will be co-promoted by Genentech and IDEC and supported by both companies' newly established oncology sales forces."

There are approximately 250,000 patients in the United States with B-cell non-Hodgkin's lymphomas, which are malignancies of the body's antibody-producing immune system cells. Approximately one-half are low-grade or follicular lymphoma patients. A portion of these patients will have multiple relapses and may be eligible for RITUXAN™ (Rituximab) therapy. Currently, standard treatment consists of chemotherapy and/or radiotherapy. Unlike the typical four- to six-month chemotherapy regimen or high- dose radiation treatment, Rituxan can be administered in four infusions on an outpatient basis over a 22-day period.

Rituxan works by binding to a particular protein (the CD20 antigen) on the surface of mature B cells and B-cell tumors. Then it recruits the body's natural defenses to attack and kill both malignant and normal mature B cells. Stem cells present in the bone marrow lack the CD20 antigen and are, therefore, not affected by the treatment. In clinical studies, B cells returned to normal levels within several months after completion of treatment.

IDEC discovered Rituxan and developed the product in collaboration with Genentech, F. Hoffmann-La Roche, Ltd of Switzerland and Zenyaku Kogyo Co., Ltd. of Japan. IDEC and Genentech will be co-promoting Rituxan in the United States and will have shared responsibility for product manufacture. Roche will be responsible for marketing Rituxan in the rest of world, excluding Japan. In financial reporting, Genentech will book all the sales and Genentech expenses related to the product in the United States. The profit will be split between the two companies based on a formula which provides Genentech with the majority share.

Genentech, Inc. is a leading biotechnology company that discovers, develops, manufactures and markets human pharmaceuticals for significant unmet medical needs. Eleven of the currently marketed biotechnology products stem from Genentech science. Genentech markets or promotes eight biotechnology products in the United States. The company has headquarters in South San Francisco and is traded on the New York Stock Exchange and Pacific Exchange under the symbol GNE.

F. Hoffmann-La Roche, Ltd, with headquarters in Basel, Switzerland, is a member of the Roche Group, a world leader in research-based health care with major businesses in pharmaceuticals, diagnostics, vitamins and fine chemicals, and fragrances and flavors. Roche has a long tradition of innovative breakthroughs in drug development and is a pioneer in the medical applications of genetic engineering.

IDEC Pharmaceuticals focuses on developing targeted immunotherapies for the treatment of cancer and autoimmune disease which are primarily designed to act through immune mechanisms. IDEC Pharmaceuticals is a registered U.S. trademark, and Rituxan is a U.S. trademark of IDEC, which is headquartered in San Diego, California.

The statements made in this news release contain certain forward looking statements that involve a number of risks and uncertainties. Actual events or results may differ from IDEC's expectations. In addition to the matters described in this news release, timelines for ongoing and future clinical activity are subject to change, results of pending or future clinical trials cannot be accurately predicted and decisions by the FDA and other regulatory agencies, including their determination as to whether there is sufficient clinical data and compliance with all other requirements to support product licensure, as well as the risk factors listed from time to time in IDEC's SEC filings, including but not limited to its annual reports on Form 10-K for the year ended December 31, 1996, and Form 10-Q/A filed August 18, 1997, may affect the actual results achieved by IDEC.

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