Clopidogrel bisulfate (Plavix®, Sanofi and Bristol-Myers Squibb): another billion dollar drug under attack by the generics

Patentability of enantiomers of well-known racemates deserves closer scrutiny. Pharmaceutical companies have most often attempted to evaluate enantiomers of a racemate much later, after the initial discovery of the racemate, even though it has been known that enantiomers differ in pharmaceutical properties. Thus, patentability of enantiomers rests on enablement but must be evaluated considering the advances in enantiochemistry in recent years, which indicates feasibility of separation of enantiomers. The outcome of the Plavix case may set another precedent and affect the development of chiral derivatives.