AMERICAN BIOGENETIC SCIENCES, INC. TO HUMANIZE ITS UNIQUE MONOCLONAL ANTIBODY MH-1

Antibody Has Multiple Therapeutic Applications In The Management Of Thrombosis And As A Potential Cancer Therapeutic Delivery System

Copiague, New York - March 22, 2000 - American Biogenetic Sciences, Inc. (ABS)(OTCBB:MABA), announced today that it is seeking a partner to humanize the company's patented anti-fibrin monoclonal antibody MH-1. This antibody has proved to be a safe, rapid and effective diagnostic imaging agent for detection of thrombi (blood clots) such as deep vein thrombosis (DVT) and pulmonary embolism (PE). The product has several other clinical applications. ABS has obtained a license for the patented technology for humanizing monoclonal antibodies from the Medical Research Council of Great Britain.

"The MH-1 imaging agent is an antibody that is highly specific for polymeric fibrin, a major component of a blood clot", explained Professor G. V. R. Born, MB.CHB. D. Phil., Director of the William Harvey Research Institute, St. Bartholomew's Hospital, London, England, and a Director of ABS. "I strongly support the decision to humanize this monoclonal antibody given its properties and its clinical imaging ability. In phase I/II human clinical trials, MH-1 imaging agent clearly detected pulmonary embolism and deep vein thrombosis, two serious thrombotic conditions with high associated morbidity. The properties of this antibody are likely to make it suitable, if humanized, for use in the treatment of clinical indications including thrombolysis (the break up of a blood clot)."

The U.S. Food & Drug Administration (FDA) has accepted the completion of Phase I studies of MH-1 for imaging DVT and PE. The agent was used successfully in fifty patients. Furthermore, the FDA has allowed the company to proceed with Phase I/II clinical studies.

• In pre-clinical studies MH-1 has demonstrated antithrombotic effects for both fibrin and platelet deposition. Humanization of MH-1 will have potential for multiple and/or continuous dosing for prevention of clot formation.
  
  
• In pre-clinical studies MH-1 has demonstrated utility as a site-specific delivery vehicle for thrombolytics (clot dissolving drugs). The extremely high specificity of MH-1 for cross-linked fibrin permits site directed thrombolysis. This should translate as a subsequent and significant reduction in the dose of thrombolytic administered, which confers a major reduction in risk of bleeding.
  
  
• Recent in vitro studies have demonstrated the utility of MH-1 for imaging fibrin deposition on live A375 (human myeloma) cells via confocal laser scanning microscopy. This agent may therefore have potential in imaging fibrin deposition during tumor build up in vivo, thereby allowing anti-cancer agents to be attached to MH-1 for site directed anti-tumor genesis.

A recent study entitled "Therapeutic and Diagnostic Monoclonal Antibodies", published by Decision Resources, predicted that revenues from therapeutic monoclonal antibodies in seven major pharmaceutical markets (U.S., Japan and five European countries) will grow from about $500 million in 1998 to a total of $4.4 billion in 2008. Currently there are at least eight therapeutic antibodies sold in the US for a range of disorders including cardiovascular disease, cancer, and organ rejection. The Pharmaceutical Research and Manufacturers of America have reported that monoclonal antibodies comprised 20% of all biopharmaceuticals in clinical development in 1998.

American Biogenetic Sciences, Inc. based in Copiague, N.Y., 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. ABS also seeks out new technologies and conducts research and development through its Global Scientific Network in the United States, 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 Companys' Securities and Exchange Commission filings including their annual report of Form 10-K.