Bio-Technology General Announces Two Major Anti-Cancer Collaborations.

ISELIN, N.J.--(BUSINESS WIRE)--April 27, 1999--

-- Company to Develop Novel Cancer Vaccine and

Anti-Angiogenesis Agent --

In a major thrust into the cancer therapeutic arena, Bio-Technology General Corp. (NASDAQ:BTGC) today announced that it has entered into research and license agreements with Massachusetts General Hospital ("MGH") and with Yeda Research and Development Company Ltd. ("Yeda"), the licensing arm of The Weizmann Institute of Science in Rehovot, Israel ("The Weizmann").

The agreement with The Weizmann relates to the development of peptide-based vaccines for the treatment of cancer. BTG will provide research funding and make certain milestone payments to the Weizmann Institute's commercial arm as well as pay royalties on any peptide-based vaccines resulting from the research which BTG markets under the exclusive license.

BTG scientists will conduct research in collaboration with Prof. Leah Eisenbach, a leading scientist in the field of tumor immunology from the Department of Immunology at The Weizmann. The aim of this research approach is to stimulate a tumor-specific immune response in the body based on the administration of certain peptides (protein fragments). These peptides stimulate the body to produce a certain type of cell (cytotoxic T lymphocyte) that attacks specific tumor cells with the objective of eliminating the cancer and conferring an immunity which protects the patient from recurrence of the disease.

BTG will concentrate its initial efforts on developing vaccines for the treatment of transitional cell carcinoma (TCC) of the bladder, breast, and colon. Breast and colon carcinomas are two of the leading cancers in the Western world. Over 50,000 new bladder cancer patients are diagnosed each year in the United States alone where it is the twelfth leading cause of cancer death. TCC is the most prevalent type of bladder cancer. Although early detection followed by surgery provides good prognosis for patients with TCC, many experience recurrence of the disease and require additional treatment. Such patients may therefore be especially appropriate candidates for a cancer vaccine.

A number of companies are involved in developing cancer vaccines which require a patient-specific vaccine formulation, an approach which is both cumbersome and costly. In contrast, BTG anticipates that its vaccine formulation, which will not be patient-specific, will be applicable to a large segment of the targeted cancer patient population.

Commenting on the collaborations, Sim Fass, BTG's Chairman, President and CEO stated: "For some time now, BTG has been conducting combinatorial research, focusing on the isolation of receptor-specific peptides targeting cancer cells. The two new anti-cancer approaches we are pursuing through the relationships with Massachusetts General Hospital and The Weizmann Institute are an extension of that research. Inducing the body to effectively mount a powerful immune response strong enough to ward off cancer progression is emerging as a highly promising clinical approach. We are indeed very excited to now be part of this important area of research and development."

The agreements with MGH relate to a novel anti-cancer approach using a proprietary plasminogen-related peptide ("PRP"). Preliminary experiments with recombinant PRP ("rPRP") in the Lewis Lung cancer mouse model have demonstrated its anti-cancer activities. The finding that rPRP may possess anti-angiogenic and anti-cancer activity was jointly discovered by Lawrence Weissbach, Ph.D. and Valerae Lewis, M.D. of MGH along with Michael O'Reilly, M.D. of Children's Hospital in Boston, Massachusetts.

BTG will produce rPRP and conduct research on its use as an angiogenesis inhibitor (an agent that blocks blood vessel development) at its facility in Rehovot, Israel in collaboration with Lawrence Weissbach, Ph.D., of MGH, the discoverer of PRP, which he cloned and expressed in E. coli. BTG will fund the research and make certain milestone payments to MGH as well as pay royalties on any resulting therapeutic products based on PRP which BTG markets under the exclusive license with MGH.

The preliminary assessment by Drs. Weissbach, Lewis, and O'Reilly is that rPRP can inhibit tumor-associated angiogenesis, thus blocking further blood vessel development within malignant growths, "choking" the blood supply to the tumor and inhibiting its growth. This approach should be applicable to all solid tumors, and should eliminate some of the problems associated with conventional solid tumor-targeted chemotherapy, such as poor tissue accessibility and drug resistance.

While a number of companies are developing angiogenic inhibitors as anti-cancer therapeutics, no anti-angiogenic drug has yet been approved for use in cancer patients.

Sim Fass also stated: "Development of safe and effective angiogenesis inhibitors has become a research focus that has generated great interest recently. The anti-angiogenic peptide developed at Massachusetts General Hospital is particularly exciting to us because it is a fragment derived from a human protein and can be produced with ease, unlike others being developed."

Bio-Technology General Corp., a leading biopharmaceutical company, develops, manufactures and markets genetically engineered and other products for human health care. BTG's products are marketed in over thirty countries worldwide.

Statements in this news release concerning the Company's business outlook or future economic performance; anticipated profitability, revenues, expenses or other financial items; and statements concerning assumptions made or expectations as to any future events, conditions, performance or other matters, are "forward-looking statements" as that term is defined under the Federal Securities Laws. Forward-looking statements are subject to risks, uncertainties and other factors which could cause actual results to differ materially from those stated in such statements. Such risks, uncertainties and factors include, but are not limited to, changes and delays in product development plans and schedules, customer acceptance of new products, changes in pricing or other actions by competitors, patents owned by the Company and its competitors, and general economic conditions, as well as other risks detailed in the Company's filings with the Securities and Exchange Commission.