Amgen Inc. v. Sanofi , Appeal No. 2020-1074 (Fed. Cir. Feb. 11, 2021) In this week’s Case of the Week, the Federal Circuit affirmed a district court’s JMOL ruling that asserted claims of two related pharmaceutical patents were invalid because their shared specification did not enable the full scope of the claims. The patents were directed to synthetic antibodies used in high cholesterol treatments that operate by binding to specified amino acids (or “residues”) of enzyme PCSK9, thereby blocking PCSK9 from binding to LDL cholesterol receptors (“LDLR”) and permitting those receptors to remove LDL cholesterol from the bloodstream. The claims at issue contained dual functional limitations, requiring that a claimed antibody both bind to at least one or two of numerous listed PCSK9 residues (i.e., in ranges from one or two residues to all of them), and that the antibodies block the PCSK9/LDLR interaction. Appellee Sanofi contended that because there are millions of antibody candidates potentially falling within the scope of the claims, and because antibody generation is unpredictable, practicing the full scope of the claims would require substantial trial and error in screening each candidate antibody for the claimed binding and blocking functionalities. Appellant patent owner Amgen contended that in finding the claims not enabled, the district court erred by focusing on the effort required to discover and make every embodiment of the claims, that the patent adequately disclosed the required screening methods, and that the examples provided were sufficiently structurally representative to enable the claims.