Last week, the United States Court of Appeals for the Federal Circuit issued an opinion in Merck Sharp & Dohme Corp. v. Wyeth LLC, Nos. 2018-2133, -2134 (Nov. 16, 2019), vacating the Patent Trial and Appeal Board’s determination that dependent claim 18 of Wyeth’s U.S. Patent No. 8,562,999 (“the ’999 patent”) is not unpatentable for obviousness.
The ’999 patent is directed to formulations for stabilizing polysaccharide-protein conjugate vaccines. Merck petitioned for inter partes review of several claims of the ’999 patent. The Board instituted review of all challenged claims, and found all but claim 18 unpatentable as obvious. As to claim 18, Merck relied on a primary reference, Peña, that did not identify the particular carrier protein used therein, but was otherwise identical to the claimed conjugate vaccine. Because the carrier protein of claim 18 appeared elsewhere in the prior art, Merck argued that Peña, combined with this other prior art, rendered claim 18 obvious. The Board determined that Merck failed to show that one of skill in the art would have been motivated to combine the prior art references to use the particular carrier protein of claim 18 with the conjugate vaccine taught by Peña or that such person would have had a reasonable expectation of success. Merck appealed.
On appeal, the Federal Circuit concluded the Board failed to present sufficient reasoning for its determination that Merck had not demonstrated that one of skill in the art would have been motivated to combine the prior art references at issue. Specifically, the Court determined there was conflicting evidence on this issue, and the Board did not sufficiently articulate how it had evaluated the conflicting evidence. Absent that articulation, the Court explained, it could not decide whether the Board’s ultimate conclusion was correct. Stating “we conclude that the Board’s decision is too cryptic to survive judicial review,” the Court vacated and remanded for further consideration of the evidence and arguments on the issues of motivation to combine and reasonable expectation of success.