The Court of Appeals for the Federal Circuit, in Immunex Corp. v. Sanofi-Aventis U.S. LLC, 977 F.3d 1212 (Fed. Cir. 2020), affirmed the PTAB’s construction of “human antibody” in an IPR to include antibodies that are fully and partially human in structure. The CAFC determined that the patent owner’s filing of a terminal disclaimer after briefing the appeal did not entitle the claims to construction under the Phillips standard. The CAFC also determined that the PTAB was not obligated to justify arriving at a different construction than a district court did in a parallel infringement proceeding. Finally, because the intrinsic evidence made the proper construction clear, the PTAB was correct to give little weight to extrinsic evidence.