Sanofi Takes Patent Hit

Sanofi-Aventis(SNY Quote) said Friday that it lost a U.S. patent challenge to its best-selling drug, the anticoagulant Lovenox.

If the ruling by a federal District Court in California stands, the French drugmaker could see 60% of its Lovenox sales at risk to generic competition five years before the company says the patent would expire. Importantly however, the Food and Drug Administration hasn't approved any generic versions yet.

For the nine months ended Sept. 30, Lovenox recorded $2.37 billion in worldwide sales, accounting for 8.6% of Sanofi's corporate revenue. The drug has been available in Europe since 1987 and in the U.S. since 1993.

Sanofi said in a press release that it was "currently evaluating its options for further legal recourse and will continue to vigorously defend its intellectual property rights."

Israel's Teva Pharmaceutical Industries(TEVA Quote), the world's largest generic-drug maker and the private California company Amphastar Pharmaceuticals brought the case against Sanofi.

Lovenox is different than Sanofi's other big anticoagulant Plavix, which also is embroiled in a U.S. patent lawsuit. Plavix is its second-biggest drug, producing sales of $2.19 billion for the nine months ended Sept. 30.

Lovenox is an injectable drug used in protecting patients against deep vein thrombosis -- blood clots that usually develop in the legs. If the clots break free, they can wind up in the lungs causing dangerous and potentially fatal consequences.