AMERICAN BIOGENETIC SCIENCES, INC. PANEL REVIEWS ANTIBODY TECHNOLOGY AT INTERNATIONAL MEETING OF IMMUNOLOGISTS

Copiague, New York, April 23, 2001 - American Biogenetic Sciences, Inc. (ABS) (NASDAQ:MABA) announced today that Scientists working with ABS reported data showing that the company’s antigen-free (A-F) mice have a significantly stronger immune response to immunization than do germ-free or conventional laboratory mice. Antigen free mice were shown to have a stronger T cell response and IgG antibodies in sera were shown to have three fold higher average affinity. This could lead to more efficient production of monoclonal antibodies due to a better “sound/noise” ratio, especially involving “difficult” antigens, emphasized by Professor Nico Bos of the Department of Cell Biology, University of Groningen, The Netherlands.

The Co-chairman of the Congress, Professor Rem V. Petrov, D.Sc., Vice President of the Russian Academy of Sciences, noted, “Over 1,000 scientists and theoretical and clinical immunologists from forty-five countries attended this international congress. Some of those present were unaware of ABS’ antigen-free technology and many remarked on its outstanding potential in the field of immunological research and the production of high affinity and very specific monoclonal antibodies in particular.”

The findings were reviewed at the VII International Congress on Immunorehabilitation, New York City (April 14-17, 2001), as part of a roundtable session at which American Biogenetic Sciences and co-investigators detailed features of ABS’ antigen-free technology and its clinical potential. The panel was chaired by Company Chairman and CEO Alfred J. Roach and included presentations by:

James H. McLinden, Ph.D., Senior Vice President and Chief Scientific Officer, ABS

Nico Bos, Ph.D., Dept. of Cell Biology, University of Groningen, The Netherlands

David Carville, Ph.D., Cardiovascular Consultant to ABS

Studies conducted by the Department of Cell Biology at the University of Groningen concluded that when research antigens were presented to A-F mice, the A-F mice made more antigen-specific antibodies with higher affinity than did their germ-free and conventional counterparts.

Renowned theoretical and clinical scientists who attended the Conference included Prof. John W. Hadden, Division of Immunopharmacology, Department of Internal Medicine, University of South Florida College of Medicine, Prof. Michael Sela, Israel, Past President of International Union of Immunological Society, Prof. Alain de Weck, President of the International Association Of Allergology And Clinical Immunology (IAACI), Switzerland.

MH-1, a monoclonal antibody developed with A-F technology, is a sensitive marker for a protein whose levels begin to rise just as a blood clot begins forming. The panel reviewed data that suggests that MH-1 may have utility as a thrombus-seeking drug delivery vehicle for thrombolytics and also anticancer agents designed to shrink tumors and prevent them from spreading.

The antithrombotic utility of this agent for the inhibition/prevention of restenosis following coronary intervention was also discussed. Data from preclinical studies demonstrating this clinical phenomenon were presented.

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 press 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, including the risk that its products may not be commercialized. 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