Publications & Presentations
July 14, 2021

US Supreme Court limits Patent Law’s assignor estoppel doctrine

Author, IAM

The assignor estoppel doctrine set out under the US Patent Law bars the inventor and those in privity with them from challenging an assigned patent’s validity during infringement litigation. In Minerva Surgical v Hologic Inc, the Supreme Court limited the doctrine, holding that it “applies when, but only when, the assignor’s claim of invalidity contradicts explicit or implicit representations he made in assigning the patent”. The case has implications for corporate patent procedures and transactions and raises issues for the lower courts.