Wednesday, Jun 6, 1984

Promising New Anti-Cancer Drug Produced By Genentech

South San Francisco, Calif. -- June 6, 1984 --

Genentech scientists have produced a new type of anti-cancer agent, called lymphotoxin, that can destroy malignant tissue. Because of its unique therapeutic potential, the substance has been designated as a top priority product joining gamma interferon in Genentech's fight against cancer.

Unlike any other anti-cancer agent, lymphotoxin can selectively kill tumor cells by breaking apart the cell membranes.

The protein is normally produced in miniscule amounts by the body's immune system, as part of the body's natural defense against disease. Until Genentech's research breakthrough, however, lymphotoxin was so rare that it was exceedingly difficult to obtain in purified form for study as a medical treatment. Quantities of the drug are now being produced by Genentech through the use of recombinant DNA technology ("genetic engineering"), and preclinical evaluation is under way.

Preliminary research results on the anti-cancer effects of Genentech's lymphotoxin are very encouraging. Because the product is a natural part of the immune system, it can distinguish between healthy and malignant tissue. Lymphotoxin has been shown to focus directly on the destruction of tumor cells without harming normal cells. It also may have a secondary role in stimulating the body's defenses against cancer. In contrast, conventional therapies such as chemotherapy and radiation treatment lack lymphotoxin's selectivity, and tend to kill both malignant and healthy cells.

Lymphotoxin could significantly improve overall cancer treatment. However, its development in no way diminishes the company's excitement about gamma interferon, another anti-cancer agent under development by Genentech. Because cancer is a very complex disease, for which no one drug is expected to be a "cure-all," Genentech is developing a family of products for cancer treatment. Lymphotoxin and gamma interferon have different anti-cancer properties and may prove highly effective alone against separate types of cancer. Furthermore, Genentech's research has demonstrated that these two proteins of the immune system have synergistic anti-cancer effects that could lead to a combination therapy against some malignancies.

Genentech's development of genetically engineered lymphotoxin was reported today, for the first time, during a scientific seminar on the lymphkines. (Lymphotoxin is a type of lymphokine.) The seminar was held at the University of Texas M.D. Anderson Hospital and Tumor Institute in Houston, Texas.

Genentech scientists have been the first to purify lymphotoxin from natural sources, determine its molecular structure, identify its biological activity, and genetically engineer an organism to manufacture the product. Lymphoxin is viewed as the first of a new class of genetically engineered proteins having tumor necrosis activity (the ability to break apart and kill tumor cells). Details on the genetic engineering ("cloning and expression") of lymphotoxin will be published in the scientific literature at a later date.

Lymphotoxin is one of five top priority products announced by Genentech. Other priority products for human and animal health include: human growth hormone (Protropin), bovine interferon (Interceptor), human gamma interferon and tissue-type plasminogen activator.

Several years of development, including human clinical trials, remain before lymphotoxin will be commercially available for medical use, according to Genentech estimates. The product will be manufactured and marketed by Genentech in North America, under the company's own label.

Genentech, Inc. is a leader in the development, manufacture and marketing of recombinant DNA products for pharmaceutical, agricultural and industrial chemicals markets.

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