The U.S. Court of Appeals for the Federal Circuit recently affirmed the Patent Trial and Appeal Board’s (PTAB’s) decision upholding the patentability of Eli Lilly & Co.’s patent claims directed to reducing toxicity of a chemotherapy agent. In so holding, the Federal Circuit cited the Food and Drug Administration’s (FDA’s) skepticism of the efficacy of the methods as evidence supporting non-obviousness. See Neptune Generics, LLC v. Eli Lilly & Co., Nos. 2018-1288, 2018-1290, 2019 U.S. App. LEXIS 12492 (Fed. Cir. Apr. 26, 2019) (Before Moore, Wallach, and Hughes, J.) (Opinion for the Court, Moore, J.) Neptune Generics, LLC, Fresenius Kabi USA, LLC, and Mylan Laboratories Ltd. (collectively, the Petitioners) filed three petitions for inter partes review (IPR) against claims 1-22 of U.S. Patent No. 7,772,209 (the ?209 patent) owned by Eli Lilly & Co. The ?209 patent generally relates to methods of administering folic acid and a methylmalonic acid (MMA) lowering agent, such as vitamin B12, before administering pemetrexed disodium, a chemotherapy agent, to reduce the toxic effects of pemetrexed. The Board found that the ?209 patent was not unpatentable as obvious because it was not known in the art to pretreat pemetrexed with vitamin B12 along with folic acid and the skepticism of others, specifically the FDA, supported a conclusion of non-obviousness. The Federal Circuit found that substantial evidence supported the PTAB’s findings and affirmed.