Sanofi's Patent Problems Are Still Potent

A few words to all Sanofi-Aventis(SNY Quote) investors reveling in the recent legal victory involving Plavix: Don't get too comfortable.

First, the Plavix patent battle isn't over. A preliminary injunction won by Sanofi last week is being appealed by Apotex, the maker of a generic version of the popular anticoagulant. The formal patent-infringement trial against Apotex won't start until January.

Second, Sanofi has another patent fight looming for its best-selling drug, Lovenox. This court contest portends to be more complicated than the duel over Plavix, its second-biggest drug. The U.S. trial for Lovenox was originally set for October, but it's been postponed until December.

At stake is a drug that had worldwide sales of $1.58 billion for the first six months of 2006, or 8.8% of the company's total revenue. More than 60% of Lovenox sales came from the U.S. The injectable Lovenox, available in the U.S. since 1993, is used primarily to prevent deep-vein thrombosis, the development of clots usually in the legs, which could lead to clots in the lungs.

Plavix accounted for $1.47 billion, or 8.1%, of Sanofi's revenue for the first half of 2006. Another $2.13 billion in first-half Plavix sales was recorded by Bristol-Myers Squibb(BMY Quote), which has the U.S. marketing rights. Plavix tablets help prevent the sticking together of blood platelets, reducing the risk of clots that can cause a heart attack or stroke.