BIOTECHNOLOGY VALUE FUND EXPANDS INVESTMENT IN AMERICAN BIOGENETIC SCIENCES, INC.

COPIAGUE, New York, August 29, 2001 - American Biogenetic Sciences, Inc. (ABS) (NASDAQ:MABA) today received an additional $2 million from Biotechnology Value Fund, L.P. (BVF), increasing BVF’s total investment in ABS to $5 million. BVF originally invested $3 million in February 2000, after Abbott Laboratories licensed ABS-103, a compound under development for the treatment of certain neurological disorders.

“ABS and BVF share similar business visions and have had a positive working relationship. We appreciate the confidence they’ve placed in ABS’ management by maintaining their existing investment and substantially increasing it,” said Josef C. Schoell, President and COO of ABS. “At the same time, ABS’ management understands that all of our investors desire increased shareholder value, and we continue to work toward that goal.”

Under the terms of the agreement, BVF’s $2 million purchases 3,333 shares of Series B Convertible Preferred Stock convertible into Common Stock at a value of 60 cents a share, and five-year warrants to purchase 3,333,000 shares of Common Stock at $1 per share.

“We believe in the enormous promise of ABS-103 as a potential successor to Abbott’s leading drug in the U.S., Depakote®, and we are encouraged by Abbott’s progress with the compound,” said BVF President Mark Lampert. “Our continued investment underscores our commitment to the Company and their strong portfolio of intellectual property.”

American Biogenetic Sciences, Inc., based in Copiague, NY, researches and develops diagnostic tests for cardio-pulmonary conditions and infectious diseases, as well as 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 (including risks related to successful development and marketing of ABS-103 and other products) that could cause actual results to differ materially from those anticipated. For further details and a discussion of these risks and uncertainties, see the companies’ Securities and Exchange Commission filings including their annual report or Form 10-K.