In Lismont v. Alexander Binzel Corp., No. 14-1846 (Fed. Cir. Feb. 16, 2016), the Federal Circuit affirmed the district court’s determination that a claim of inventorship was barred by laches where the plaintiff initiated suit ten years after the patent issued.

The Court noted that a laches defense requires two showings: (1) the plaintiff’s delay in filing the suit was unreasonable and inexcusable, and (2) the defendant suffered material prejudice attributable to the delay. A rebuttable presumption of laches arises six years after the inventor knew or should have known of the patent.

Lismont had challenged the inventorship of Binzel’s foreign patents in various foreign courts for more than a decade before Lismont first challenged Binzel’s U.S. patent in a U.S. district court. Being well after six years, the Court held that the presumption of laches applied. Lismont argued in rebuttal that the foreign litigation provided the requisite notice that Lismont intended to challenge the propriety of the inventorship on the Binzel’s U.S. patent as well. The Court disagreed. Finding that Lismont failed to provide notice in the foreign courts that it would pursue litigation in the U.S., the Court held that Lismont was unable to rebut the presumption of laches and affirmed the district court.