Patent Law Alert: Supreme Court Upholds Assignor Estoppel Doctrine But Narrows Its Scope

On June 29, 2021, in Minerva Surgical, Inc. v. Hologic, Inc., the U.S. Supreme Court upheld the doctrine of assignor estoppel (which prevents inventors from challenging the validity of patents that they have assigned to third parties) as a defense in patent infringement cases, but limited the doctrine to apply only when the assignor’s claim […]