Pharmaceutical Compound Nonobvious Absent Evidence Suggesting Specific Modification to Prior Art Compound, PTAB Litigation Blog
The PTAB issued a final written decision in IPR2016-00204, upholding the validity of claims 1–13 of Patent RE38,551 E (“the ’551 patent”), which covers the antiepileptic drug VIMPAT® (lacosamide).
The petitioner, Argentum argued that a prior art publication by the inventor of the ’551 patent (“Kohn 1991”) identified compound 31 as a lead antiepileptic compound, and that only a single substitution of compound 31—a biosteric replacement of a methoxyamino group with a methoxymethyl group—was required to arrive at lacosamide. Argentum further argued, relying on expert testimony, that an ordinary artisan would have been motivated to make this replacement because compound 31’s methoxyamino group is an uncommon moiety among commercial pharmaceuticals that presents potential synthetic and stability issues, and the proposed substitute, a methoxymethyl group, is a more common acceptable moiety for pharmaceutically active compounds.
Read the full article at ptablitigation.com.