AMERICAN BIOGENETIC SCIENCES, INC. OBTAINS U.S. PATENT FOR THE TREATMENT OF MALIGNANT AND BENIGN TUMORS

Invention Utilizes Targeting Monoclonal Antibodies Generated With The Company's Patented Antigen-Free Technology

COPIAGUE, NY - February 13, 2001 - American Biogenetic Sciences, Inc. (ABS) (NASDAQ:MABA) announced today that it has been issued U.S. Patent No. 6,187,593 for an invention that is particularly useful for the treatment of malignant and benign tumors containing fibrin. ABS is actively seeking corporate partners to develop and commercialize this patented technology. ABS' current patent portfolio amounts to 23 U.S. issued patents, 57 foreign-issued patents and more than 60 additional applications pending.

This issued patent covers methods for utilizing a monoclonal antibody, MH-1, (American Biogenetic Sciences, Inc. also owns patent rights to the monoclonal antibody, MH-1, and its use.) in conjunction with a cytotoxic reagent for the treatment of malignant and benign tumors containing fibrin. These tumors account for 96 percent of all cancers. The monoclonal antibody, MH-1, will target the malignant or benign tumor containing fibrin thereby facilitating destruction via the cytotoxic reagent. The method also encompasses administering to a patient other forms of the fibrin-specific monoclonal antibody, MH-1. (For example: fragments of MH-1, or fragments of any antibody that competes with the immunospecific binding of the MH-1 antibody to its binding site; again this would utilize a cytotoxic reagent.)

According to the American Cancer Society, there are more than one million cases of cancer that are diagnosed annually in the United States. Of these diagnosed malignant tumors, there are approximately 184,200 diagnosed for breast cancer; 180,400 for prostate cancer; 93,800 for colon cancer; 23,100 for ovarian cancer; the balance being various other forms of cancer. In addition, the American Cancer Society states, "This year about 552,200 Americans are expected to die of cancer - more than 1,500 people a day. Cancer is the second leading cause of death in the U.S., exceeded only by heart disease. In the U.S., 1 of every 4 deaths is from cancer."

Commenting on the patent, ABS' Chief Scientific Officer, James McLinden, PhD, said, "This promising method for medical science results from the dedicated efforts of our scientific researchers over the years. MH-1 was discovered through ABS' proprietary, antigen-free mouse technology that produces unique monoclonal antibodies (Mabs). We believe this research will continue to develop extremely important and unique advances in cancer diagnosis and treatment." American Biogenetic Sciences, Inc., based in Copiague, N.Y., researches and develops diagnostic tests for cardio-pulmonary conditions and infectious diseases, as well as for new treatments for neurological disorders including epilepsy, migraine, mania, Parkinson's disease and Alzheimer's disease.

Statements in this release that are not strictly historical are "forward looking" statements within the meaning of the Private Securities Litigation Reform Act of 1995, and should be considered as subject to various risks and uncertainties that could cause actual results to differ materially from those anticipated. For further details and a discussion of these risks and uncertainties, see the Company's Securities and Exchange Commission filings including its annual report on Form 10-K.