Press Releases

JAPANESE PATENT GRANTED ON AMERICAN BIOGENETIC SCIENCES' NEXT-GENERATION VALPROIC ACID

Dr. Strengthened Patent Position Key Element In Attracting Marketing Partner

COPIAGUE, N.Y., May 6, 1999 -- American Biogenetic Sciences, Inc. (ABS) (Nasdaq: MABXA) has received formal notice from the Japanese Patent Office that a patent has been granted which covers ABS' lead neuroscience compound, ABS-103R. The patent, no. 507680, entitled “Valproic Acid Analogues as Antiepileptic Agents”, covers ABS-103R and related compounds for the treatment of epilepsy. The term of the new patent is 20 years from the date of filing and will expire on September 10, 2013. ABS intends to seek marketing partners who will help develop ABS-103R as a next-generation replacement for the widely used neurology drug valproic acid for the treatment of epilepsy, prevention of migraine, and manic depression.

“This is an important and timely event, as we advance our discussions with potential commercialization partners in Japan, the U.S. and other territories,” said John S. North, President and CEO of ABS. “Securing a strong patent position for ABS-103R is vital and we anticipate that the issuance of the Japanese patent will be considered a key asset by prospective partners, further strengthening interest in this compound, particularly since it can be difficult to obtain intellectual property protection in Japan.”

ABS-103R is a single-isomer, next-generation version of valproic acid, one of the most widely-used neurology drugs currently available. Valproic acid is sold in North America by Abbott Laboratories (NYSE:ABT), in Europe by Sanofi, and in Japan by Kyowa Hakko and generates annual worldwide sales in excess of $1 billion. Valproic acid is used to prevent epileptic seizures, to control the mania associated with manic depressive illness, and is one of the few medicines indicated for the prevention of migraine headaches. However, the use of valproic acid is severely restricted, because its side-effects can include birth defects, liver toxicity, sedation and weight gain. ABS-103R, which is in preclinical trials, is similar in efficacy and chemical structure to valproic acid, but has a surprisingly better safety profile than valproic acid.

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

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