The Supreme Court of the United States agreed to review assignor estoppel in patent cases. Minerva Surgical, Inc. v. Hologic, Inc., et al., Case No. 20-440 (Supr. Ct. Jan. 8, 2021) (certiorari granted). The question presented is:

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.

Csaba Truckai is the inventor of two patents relating to endometrial ablation that were ultimately acquired by Hologic. Truckai later founded Minerva and developed a system that competed with Hologic’s system. The district court ruled that Minerva could not challenge the validity of the patents because Truckai was barred by assignor estoppel from attacking his own patents. A jury found that Minerva infringed both patents and awarded Hologic more than $4.7 million. On appeal, the US Court of Appeals for the Federal Circuit affirmed, confirming that assignor estoppel bars an assignor from asserting invalidity of an assigned patent in district court, and “declined Minerva’s invitation to ‘abandon the doctrine’ of assignor estoppel entirely.”