By Lisa Seachrist

Washington Editor

WASHINGTON — Following news of a successful Phase III trial for its lead cardiovascular product, COR Therapeutics raised more than $55 million in a public offering.

The South San Francisco company sold 2.9 million shares, which was 400,000 more than anticipated, at $19 a share for a total of $55.1 million. When COR registered for the offering in September it proposed selling 2.5 million shares and its stock (NASDAQ:CORR) was trading at $15.437. The company gained another $2.75 Tuesday to close at $21.75.

The offering was underwritten by BancAmerica Robertson Stephens, of San Francisco, and Hambrecht & Quist L.L.C. and Oppenheimer & Co. Inc., both of New York. They have overallotment options to purchase up to 435,000 additional new shares.

As of June 30, COR had cash, cash equivalents and short-term investments of $38.52 million. The company estimated that funds from the offering will see its lead anticoagulant product, Integrilin, through FDA approval and support other research efforts through 1999.

Integrilin (eptifibatide), an inhibitor of platelet aggregation, is a synthetic peptide derived from the venom of southeastern Pygmy rattlesnakes. Integrilin specifically blocks the glycoprotein (GP) IIb-IIIa receptor, which mediates platelet aggregation. The company last winter sought approval of Integrilin on the basis of the IMPACT II angioplasty trial, but the FDA's Cardiovascular Renal Drugs Advisory Committee advised that more trial data were needed. The FDA ultimately agreed with the advice and sent COR a non-approvable letter.

Earlier this month, COR amended its new drug application to include the results of a successful Phase III trial involving 11,000 patients. The trial was conducted in patients with unstable angina and non-Q-wave myocardial infarction and showed that Integrilin produced a statistically significant reduction in death or heart attack in these patients.

An FDA decision on Integrilin could come as soon as the second quarter of 1998 and, if approved, the company could market the product as soon as the third quarter of 1998.

COR has an agreement with Schering-Plough Corp., of Madison, N.J., giving the pharmaceutical firm worldwide marketing rights. COR would copromote the product in the U.S. and Canada. And, after receiving royalties from European sales for a specified period of time, the company could copromote in Europe as well.

COR also has collaboration agreements with Ortho Pharmaceuticals, Kyowa Hakko Kogyo Co. Ltd. and Eli Lilly & Co. for other products.

If Integrilin is approved for marketing, its main competitor would be ReoPro, which was developed by Malvern, Pa.-based Centocor Inc. and marketed by Lilly, of Indianapolis. ReoPro, a monoclonal antibody, also targets the GP IIb/IIIa receptor. *