In Minerva Surgical v. Hologic, No. 21-440, slip op. (Fed. Cir. June 29, 2021), the Supreme Court affirmed the existence of the defense of “assignor estoppel” in patent cases. However, the “unfairness” hurdle imposed by the Court on the doctrine may make it inapplicable except in rare cases, due to the way patent applications tend to be prosecuted.
