Press Releases

AMERICAN BIOGENETIC SCIENCES, INC. RECEIVES EXTENSION ON MARKET LISTING

Company Will Be Listed on NASDAQ Small Cap Market

COPIAGUE, N.Y., December 3, 1999 - American Biogenetic Sciences, Inc. (ABS) (NASDAQ: formerly MABXA; to become MABAC) announced today that it has received notification from Nasdaq/AMEX that, effective December 6, 1999, its stock will be listed on The Nasdaq SmallCap Market after receiving an exception from the net tangible assets and minimum bid price requirements.

ABS failed to meet the minimum bid requirement as of November 24, 1999. It failed to meet the net tangible asset requirement in the Form 10-Q as filed on August 13, 1999. However, the Company was granted an exception to these standards, subject to ABS meeting certain conditions. The exception will expire on December 31, 1999. In the event the company is deemed to have met the terms of the exception, it shall continue to be listed on The Nasdaq SmallCap Market.

The Company is actively involved in negotiations with several parties concerning strategic alliances, licensing and/or investment transactions. The Company believes that it can meet these standards, however, there can be no assurance that it will do so. If at some future date the Company’s securities should cease to be listed on The Nasdaq SmallCap Market, they may continue to be listed in the OTC-Bulletin Board. For the duration of the exception, the Company’s Nasdaq symbol will be MABAC.

American Biogenetic Sciences, based in Copiague, New York, researches and develops diagnostic tests for cardiac conditions and infectious diseases, as well as new treatments for neurological disorders including epilepsy, migraine, mania, Parkinson’s and Alzheimer’s disease. ABS also seeks out new technologies and conducts research and development throughout its Global Scientific Network, in the U.S., Europe, Israel, Russia and China.

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 or Form 10-K.