Teva Classics SAS, Teva Sante SASU and Teva Pharmaceutical Industries Ltd v. Sepracor Inc, invalidity proceedings (enantiomers), Tribunal de Grande Instance, Paris, France, 6 October 2009, Docket No. 07/16446, with thanks to Pierre Véron, Véron & Associés
Cetirizine is a chiral molecule likely to exist in the form of two enantiomers, Levocetirizine (-) and Dextrocetirizine (+). The French first instance court invalidates the French part of Sepracor's European Patent 0 663 828 that relates to the use of Levocetirizine for the manufacture of a drug for treating allergic rhinitis or allergic asthma, for insufficient disclosure. On the same day the '828 patent was filed, Sepracor filed a patent application, which claims the use of dextrocetirizine (the (+) cetirizine enantiomer) for treating the same allergies and that it is completely identical to the other patent application except for a word.
The court rules that the absence of any mention of research and result proves the speculative nature of the patent application and, as a consequence, conceals the lack of inventive step. The existence of the 'sister' patent application of the patent in dispute in the view of the court moreover tends to establish that on the filing date of these patent applications Sepracor had no information to decide which one of the two enantiomers was the most efficient one (or had the least adverse effects), or even whether one of the two enantiomers was more efficient (or had less adverse effects) than the racemic form.