On Remand from SCOTUS, CAFC Again Upholds Ruling for Hologic Based on Assignor Estoppel

The U.S. Court of Appeals for the Federal Circuit (CAFC) today, in a precedential decision, revisited its 2020 holding that the doctrine of assignor estoppel bars Minerva Surgical, Inc. from challenging the validity of Hologic Inc.’s patent directed to a device for treating a uterus. The decision comes on remand from the U.S. Supreme Court, which vacated the 2020 ruling and returned it to the CAFC for further consideration of the Justices’ determination that the doctrine of assignor estoppel comes with certain limits. The Supreme Court ruled in June 2021 that assignor estoppel—which bars the assignor of a patent from later attacking the patent’s validity—“is well grounded in centuries-old fairness principles…[but] applies only when the assignor’s claim of invalidity contradicts explicit or implicit representations he made in assigning the patent.” Thus, while the Court rejected Minerva’s request that the doctrine be abandoned, it vacated the CAFC’s 2020 judgment and remanded the case to address “whether Hologic’s new claim is materially broader” than the ones that were assigned.Read More