Sanofi-Aventis loses US Lovenox patent case

French pharmaceutical major Sanofi-Aventis saw its share price come under pressure on February 9, after the company revealed a negative US court ruling regarding the patent infringement law suit on its blockbuster antithrombotic Lovenox (enoxaparin), which was in favor of US generics firm Amphastar and Israel-headquartered Teva Pharmaceutical Industries.

Sanofi-Aventis says it is evaluating its options for further legal recourse and will continue to "vigorously defend its intellectual property." Lovenox generated revenues of around $2.4 billion in the first nine months of 2006. The news comes at a time that a US court is hearing the company's defense of its Plavix (clopidogrel) patent against Apotex (Marketletters passim).

The California court ruling means that the Lovenox patent is officially invalid, and the separate challenge on the basis of obviousness is irrelevant, analysts at Lehman Brothers point out. However, importantly, this ruling does not result in a generic enoxaparin on the US market immediately. To date, the Food and Drug Administration has not granted tentative approval to any generic company for this compound.