The Federal Circuit affirmed six PTAB decisions that held unpatentable as obvious 79 claims of three Cytiva Bioprocess (“Cytiva”) challenged patents and reversed the PTAB decision upholding four claims.
JSR Corp. (“JSR”) filed six inter partes reviews challenging 83 claims across three patents generally related to affinity chromatography, a process for separating biomolecules from a mixture using molecular binding. The Board found that the composition claims, which included a modified ligand protein for target binding, were unpatentable as obvious based on express suggestions in the prior art, but that certain process claims were not unpatentable because JSR had failed to show a reasonable expectation of success.
On appeal from both parties, the Federal Circuit held that the Board did not err in failing to apply the “lead compound analysis,” as argued by Cytiva. The lead compound analysis is a two-step test in which a person of ordinary skill in the art must have had: (i) a reason to select a prior art compound as a “lead,” and (ii) a reason to modify the prior art compound with a reasonable expectation of success. Otsuka Pharm. Co. v. Sandoz Inc., 678 F.3d 1280, 1291–92 (Fed. Cir. 2012). The Court held that the analysis “is not required where the prior art references expressly suggest the proposed modification” as here. Further, the Board’s application of the KSR obvious to try rational was not erroneous because of: (i) a design need to solve the ligand stability problem, and (ii) a finite number of identified, predictable solutions: the point and type of ligand modification, expressly thought by the prior art.
As for the remaining four claims upheld by the Board, the Court held that they simply describe an inherent property – a molecule’s ability to bind to an antibody – therefore, “there is no question of a reasonable expectation of success,” relying on Hospira, Inc. v. Fresenius Kabi USA, LLC, 946 F.3 1322, 1332 (Fed. Cir. 2020). Therefore, the Board’s reasonable expectation of success inquiry was erroneous, because the claims recited an inherent property of “an otherwise obvious composition.”
