Monday, Aug 17, 1998

Pivotal Clinical Trial of First Monoclonal Antibody

Projected Median Time to Progression of Disease is 13.0 Months for Intent-to-Treat Patients; Nearly 70 Percent of Responders Still in Remission

San Diego and South San Francisco, Calif. -- August 17, 1998 --

IDEC Pharmaceuticals Corporation (NASDAQ: IDPH) and Genentech, Inc. (NYSE: GNE) today announced that study results on projected median time to progression of disease for Rituxan™ (Rituximab) were published in the August 1998 issue of the Journal of Clinical Oncology. Final study data will be re-analyzed after all the patients have relapsed. Rituxan is indicated for the treatment of relapsed or refractory low-grade or follicular, CD20-positive, B-cell non-Hodgkin's lymphoma.

In November 1997, Rituxan was approved for marketing by the U.S. Food and Drug Administration (FDA) as a single agent for the treatment of relapsed or refractory low-grade or follicular, CD20-positive, B-cell non-Hodgkin's lymphoma. It is the first new therapy in 10 years for non-Hodgkin's lymphoma and the first monoclonal antibody (MAb) licensed for the treatment of cancer in the United States.

In the pivotal trial conducted at 31 U.S. sites, Rituxan, when used alone, showed a 48 percent overall response rate in 166 intent-to-treat patients. Ten of these were complete responses (6%) and 70 were partial responses (42%) as measured by a blinded independent Response Evaluation Committee. Among those who did not achieve a complete response or partial response, the majority (56 of 75) nonetheless had a net decrease of measurable disease (mean decrease, 32%).

Of 166 intent-to-treat patients, with a median follow-up duration of 11.8 months, the projected median time to progression for responders (76) was 13.0 months. To date, nearly 70 percent of these patients (53 of 76) continue to respond to the outpatient treatment course of Rituxan. The study also concludes that most toxicity with Rituxan was mild. The majority of adverse events occurred during the first infusion and were grade 1 or 2 (mild to moderate). Fever and chills were the most common events. Only 12 percent of patients had grade 3 (severe) and, 3 percent, grade 4 (life-threatening) toxicities.

The response rates for Rituxan were what would be expected with a single-agent cytotoxic therapy in the setting of relapsed lymphoma. Median duration of response to prior chemotherapy among responders was 12 months. Thus, Rituxan induced a remission of equal duration to alternative therapies. Additionally, in the natural course of the disease, typically each subsequent remission usually is of shorter duration.

"These good response rates and time to progression data, along with the mild toxicity profile, suggest that Rituximab as a single-agent is an appropriate new treatment option for patients with relapsed indolent lymphoma," said Peter McLaughlin, M.D., associate professor of medicine, University of Texas, M.D. Anderson Cancer Center. "It is also a very appealing agent to consider for further investigation, such as in an adjuvant role or in conjunction with chemotherapy."

"With a response rate that is reported with standard single-agent chemotherapy, a favorable side effect profile, and now a median time to progression of more than a year, it is exciting for Genentech and IDEC to see that non-Hodgkin's lymphoma patients are experiencing the clinical benefits of Rituxan," said Antonio J. Grillo-López, M.D., IDEC's chief medical officer.

Rituxan is administered in four infusions over a 22-day period in an outpatient setting often in a physician's office. Special handling of the therapy or patient is not required.

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

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. Of these patients, about half are diagnosed with low-grade or follicular lymphoma and the other 50 percent with intermediate-grade to high-grade lymphoma. Currently, standard treatment consists of chemotherapy and/or radiotherapy.

IDEC Pharmaceuticals 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 co-promote Rituxan in the United States and have shared responsibility for product manufacture. Roche is responsible for marketing Rituxan in the rest of world, excluding Japan, under the product name MabThera®.

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, six of which Genentech markets in the United States. The company has headquarters in South San Francisco, California and is traded on the New York Stock Exchange and the Pacific Exchange under the symbol of 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 that are designed primarily 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.

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