Counsel's Actions Support Inference Of Intent To Deceive PTO

In a decision clarifying the analysis for inequitable conduct, a split panel of the US Court of Appeals for the Federal Circuit affirmed a district court finding of specific intent to deceive the US Patent and Trademark Office (PTO) during prosecution of an asserted patent, based largely on misconduct by litigation counsel during the district court action. Regeneron Pharmaceuticals, Inc. v. Merus N.V., Case No. 16-1346 (Fed. Cir., July 27, 2017) (Prost, CJ) (Newman, J, dissenting). The dissent argued that the decision ignored the Court's own requirement that intent to deceive must be proved and not merely inferred.

Regeneron filed suit alleging that Merus infringed its patent directed to using large DNA vectors to target and modify endogenous genes and chromosomal loci in eukaryotic cells. The patented technology allows users to target and modify specific genes in mice so that the mice develop antibodies that can be used by humans.