Minerva Surgical, Inc. v. Hologic, Inc.

Whether a defendant in a patent infringement action who assigned the patent, or is in privity with an assignor of the patent, may have a defense of invalidity heard on the merits.

The inventor of patent rights related to procedures and devices for endometrial ablation had the patents acquired by Respondents, and four years later left to work for Petitioner. Petitioner developed a patent that was approved by FDA which contained the same indication as Respondents’ patent. Respondents’ sued Petitioner for infringing certain claims of the patents. The district court held, and the Federal Circuit affirmed, that Petitioner was barred from asserting any invalidity defenses because of assignor estoppel. Petitioner argues for either a narrow construction or to discard assignor estoppel. Petitioner’s argument for discarding assignor estoppel was that (1) an assignor should have the ability to assert invalidity based on the original inventor’s specification failure to support newly obtained, broad claims; and, (2) the doctrine frustrates innovation but doesn’t serve any equitable end. Petitioner’s argument for a narrow construction was that Congress didn’t want to create a dual-track system that shielded patents from an assignor’s invalidity defenses in court but allowed said assignor to raise them in the Patent Office.