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. ...