On June 18, 2023, the U.S. Supreme Court in the matter of Amgen, Inc. et al. v. Sanofi, et al.1 unanimously upheld the 2021 decision of the U.S. Court of Appeals for the Federal Circuit,2 striking down as overbroad Amgen’s patent claim to an entire functional genus of monoclonal antibodies. Amgen’s patent claims were not limited to antibody structure or antibody amino acid sequences. This is significant because Amgen’s patent claims did have amino acid sequences, but they were directed to the epitope.