Press Releases

STUDY FINDS AMERICAN BIOGENETIC SCIENCES' TpP™ TEST 97% ACCURATE IN EXCLUDING DEEP VEIN THROMBOSIS

McMaster University Study Consistent With Data from Previous Trials

COPIAGUE, N.Y., June 2, 1999 -- American Biogenetic Sciences, Inc. (ABS) (Nasdaq: MABXA) announced today that clinical researchers at McMaster University in Hamilton, Ontario, Canada found that ABS' Thrombus Precursor Protein (TpP™) test was 97 percent accurate in ruling out a diagnosis of deep vein thrombosis (DVT). The McMaster study of 211 patients adds to a growing body of clinical evidence showing that TpP is among the most sensitive and accurate diagnostic tests used to exclude the formation of blood clots.

The study was conducted at the Hamilton Civic Hospitals Research Centre at McMaster University, under the supervision of Shannon Bates, M.D. and Jeffrey Ginsberg, M.D. “These are good results that point to the utility of TpP,” said Dr. Ginsberg. “There is a real need for reliable blood tests to aid in the diagnosis and treatment of thrombotic conditions, such as DVT. The first clinical diagnoses of these conditions is based on observation of signs and symptoms and are not accurate. The second, objective diagnoses, such as the standard venography test are expensive, invasive and can cause potentially serious side-effects. The data we have observed suggests that the TpP blood test could be very useful in a number of clinical settings.”

The McMaster data are consistent with and validate clinical trial results announced in December, 1998. In a smaller sample of 49 patients, Yale S. Arkel, M.D., Director of the Blood Disorders Center at Atlantic Health Systems, found the TpP test to be 100 percent accurate in ruling out both DVT and pulmonary embolism (PE). These and other data will be presented at the XVIIth Congress of the International Society for Thrombosis and Haemostasis in August, 1999, which will be held in Washington, D.C.

Uniqueness of test offers key advantages.

John S. North, President and CEO of ABS, emphasized the uniqueness of the TpP test and a key advantage it offers over other diagnostic tests currently on the market. “Blood tests commonly used today to diagnose thrombotic conditions are not specific for the formation of an acute clot,” said Mr. North. “They either detect that the clotting system has been activated, which is not a guarantee that a clot will form, or they detect markers released in the blood when damage has already been done and often too late for therapy to be effective. TpP, on the other hand, measures soluble fibrin, which is the immediate precursor to a clot. Elevated TpP levels indicate that there is active clotting, which is when therapeutic intervention is most effective.”

“These results are part of our ongoing post-FDA approval clinical trials program and I look forward to sharing the McMaster and other data with our prospective commercialization partners, as well as with the medical community. With some 2 million Americans presenting with symptoms of DVT each year, the potential market for TpP, in DVT alone, is immense. ABS is well poised to take advantage of this market and the development of our point of care device will significantly increase the commercial potential of TpP,” said Mr. North.

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.

.