Monday, May 18, 1998

Phase II Pilot Study of Rituxan with Chemotherapy Showed 97% Response Rate in Type of Non-Hodgkin's Lymphoma

Monoclonal Antibody Studied in Combination with CHOP Chemotherapy

Los Angeles -- May 18, 1998 --

Genentech, Inc. (NYSE:GNE) and IDEC Pharmaceuticals (NASDAQ:IDPH) today announced the results of a small Phase II investigational pilot study combining Rituxan™ (Rituximab) with standard chemotherapy. This pilot study revealed an overall response rate of 97 percent in patients with previously untreated intermediate- or high-grade non-Hodgkin's lymphoma (NHL). The full results of this Phase II pilot study, conducted in 33 patients, were presented at the annual meeting of the American Society of Clinical Oncology (ASCO) in Los Angeles today. Further large-scale clinical trials will be necessary to confirm these preliminary results.

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 NHL. It is the first new therapy in 10 years for NHL and the first monoclonal antibody (MAb) licensed for the treatment of cancer in the United States.

In the pilot study of Rituxan combined with CHOP (a standard chemotherapy regimen of cyclophosphamide, doxorubicin, vincristine and prednisone) 32 of 33 patients, 97 percent, responded to treatment with 24 complete responses (73 percent), 8 partial responses (24 percent) and one progression. No long-term follow-up data is available.

"This pilot study appears to demonstrate the feasibility of adding Rituxan to CHOP chemotherapy in intermediate - and high-grade non-Hodgkin's lymphoma patients," said Brian K. Link, M.D., University of Iowa, Iowa City, one of the principal investigators in the study. "We believe the response rates and safety profile seen in this pilot study further justify larger multicenter Phase III trials which are underway to compare the safety and efficacy results of Rituxan-plus-chemotherapy to chemotherapy alone."

"We're encouraged by these preliminary results and we are committed to continuing research in non-Hodgkin's lymphoma, one of only two cancers reported to still be on the rise in the United States," said Susan Hellmann, M.D., M.P.H., Genentech's senior vice president of Development and chief medical officer.

Overall, the pilot study showed the combination of Rituxan and CHOP therapy was well tolerated. The safety profile of Rituxan plus CHOP was similar to that observed with CHOP alone which may indicate the feasibility of combining these two therapies. The most common adverse events seen with Rituxan in combination with CHOP chemotherapy were fever, hair loss, fatigue, nausea, vomiting and low white blood cell counts.

In prior clinical trials, 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) 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 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 will be responsible for marketing Rituxan in the rest of world, excluding Japan.

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 directly 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 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.

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