By Charles Craig

IDEC Pharmaceuticals Inc. and its partner, Genentech Inc., submitted an application for approval of a monoclonal antibody to treat non-Hodgkin's B-cell lymphoma, a deadly cancer that attacks the antibody-producing immune system cells and affects 240,000 people in the U.S.

The drug, IDEC-C2B8 (rituximab), would be San Diego-based IDEC's first FDA-approved product. Company officials also said it would be the first monoclonal antibody treatment for cancer to make it to market, almost 20 years after the drugs were invented and touted as the "magic bullets" against the disease.

Submission of the biological license application with the FDA is based on Phase III clinical trial data reported in December 1996. The study showed the antibody reduced tumors by 50 percent or more in 50 percent of the patients treated. Seventy percent of those patients who responded also remained in remission during nine months of follow-up observation. (See BioWorld Today, Dec. 11, 1996, p. 1.)

IDEC and Genentech, of South San Francisco, are seeking approval to market the drug as a primary therapy for relapsed low-grade or follicular non-Hodgkin's lymphoma, which affects about two-thirds of those stricken with the cancer.

IDEC-C2B8, a chimeric monoclonal antibody, targets the CD20 antigen on the surface of B cell lymphomas and healthy mature B cells, stimulating a patient's immune system to kill the malignant cells. Although normal B cells also are destroyed, B cell precursor cells are not affected, allowing the body to replenish its immune system supply of B cells.

The treatment is considered a substitute for chemotherapy and radiation, both of which have significant toxic side effects.

Clinical studies of IDEC-C2B8 revealed it did not damage bone marrow or produce other toxic side effects associated with current treatments. The most common adverse reactions to the antibody were mild to moderate flu-like symptoms.

If the drug is approved, Genentech and IDEC will share profits for sales in the U.S. IDEC-C2B8 would be Genentech's first new marketed product in the U.S. since 1993, when Pulmozyme was cleared as a treatment for cystic fibrosis.

IDEC's partner in Europe, Roche Holding Ltd., of Basel Switzerland, submitted an application for approval of the monoclonal antibody with the European Medicines Evaluation Agency. Roche is the majority owner of Genentech.

IDEC is collaborating with Zenyaku Kogyo Co. Ltd., of Tokyo, for development of the drug in Japan.

IDEC's stock (NASDAQ:IDPH) closed Monday at $24.312, down $0.563. Genentech (NYSE:GNE) finished the day at $55.125, unchanged.

In an unrelated development, SmithKline Beecham plc, of London, reported to the Securities and Exchange Commission that it sold more than 930,000 IDEC shares, leaving the pharmaceutical company with more than 1 million IDEC shares.

IDEC and SmithKline are collaborating on development of an anti-CD4 antibody, which is in Phase III trials for treatment of rheumatoid arthritis.

IDEC officials said SmithKline's sale of stock does not reflect any change in their collaboration. Prior to the move, SmithKline owned 11 percent of IDEC. *