Affirming the district court, the U.S. Court of Appeals for the Federal Circuit reiterated its precedent that “a claim to a method of using a composition is not patentably distinct from an earlier claim to the identical composition in a patent disclosing the identical use” and confirmed that its holding “extends to any and all such uses disclosed in the specification of the earlier patent.” Sun Pharmaceutical Industries Ltd. v. Eli Lilly and Co., Case No. 10-1105 (Fed.Cir., July 28, 2010) (Prost, J.).

Eli Lilly received a. patent in 1984 for the compound gemcitabine (marketed as the cancer treatment Gemzar®). The patent was a continuation-in-part (CIP) of an earlier application that described the utility of gemcitabine for antiviral purposes only. Part of the disclosure added by the CIP was a description of gemcitabine’s utility as an anti-cancer agent. On the same day as the CIP was filed, Lilly filed a separate application with claims directed to a method of treating cancer with a class of compounds that included gemcitabine, which eventually issued as the patent in suit. Sun Pharmaceutical filed an action for a declaratory judgment that the method of treatment patent was invalid, and not infringed by Sun’s generic version of Gemzar®. The district court granted partial summary judgment that the claims of the method of use patent are invalid for obviousness-type double patenting over the CIP patent. Lilly appealed.

In affirming, the Federal Circuit rejected Lilly’s arguments that the Court’s earlier decisions in Geneva Pharmaceuticals v. GlaxoSmithKline and Pfizer, Inc. v. Teva Pharmaceuticals should be limited to their specific facts, or at least to cases in which the earlier patent disclosed only a single use for the claimed compound. The Court also rejected Lilly’s argument that the district court erred in considering the specification of the CIP, as opposed to the specification of an earlier application, to determine what uses for gemcitabine had been disclosed. The Court noted it had previously and expressly held that “where a patent claims a compound, a court performing and obviousness-type double patenting analysis should examine the specification to ascertain the coverage of the claim” and explained that “the specification that must be considered is that of the issued patent,” as opposed to “earlier drafts of the patent disclosure and claims.”