Thursday, March 11, 2021 Addressing claim construction, enablement, damages and willfulness, the US Court of Appeals for the Federal Circuit found that evidence of a defendant’s knowledge of the asserted patent and proof of infringement were, by themselves, legally insufficient to support a finding of willfulness. Bayer Healthcare LLC v. Baxalta Inc., Case No. 19-2418 (Fed. Cir. Mar. 1, 2021) (Stoll, J.) Bayer owns a patent on certain recombinant forms of human factor VII (FVIII), a protein that is critical for blood coagulation. Recombinant FVIII is useful as a treatment for coagulation disorders, primarily Hemophilia A. Natural FVIII has a short half-life, making therapeutic administration expensive and inconvenient. Adding polyethylene glycol (a process known as PEGylating) to FVIII at random sites was found to increase the protein’s half-life but reduce its function. Bayer invented FVIII that is PEGylated in a specific region (the B-domain) so that it retains its function and maintains the longer half-life.