Judges: Bryson, Gajarsa, Prost (author) [Appealed from E.D. Mich., Judge Steeh]

In Sun Pharmaceutical Industries, Ltd. v. Eli Lilly & Co., No. 10-1105 (Fed. Cir. July 28, 2010), the Federal Circuit affirmed the district court’s ruling that certain claims of Eli Lilly and Company’s (“Lilly”) U.S. Patent No. 5,464,826 (“the ’826 patent”) were invalid for obviousness-type double patenting in view of Lilly’s U.S. Patent No. 4,808,614 (“the ’614 patent”).

The ’614 patent claims the compound gemcitabine and a method of using gemcitabine to treat viral infections. The ’826 patent claims a later-discovered method of using gemcitabine to treat cancer. Gemcitabine is the active ingredient in Gemzar®, which Lilly markets for the treatment of various forms of cancer.

The ’614 patent, entitled “Difluoro Antivirals and Intermediate Therefor,” was originally filed on March 10, 1983, as U.S. Patent Application Serial No. 473,883 (“the original ’883 application”), and disclosed gemcitabine’s antiviral utility. On December 4, 1984, a CIP was filed in the ’614 family that added one paragraph to the original specification describing gemcitabine’s newly discovered anticancer activity. On the same day Lilly filed the CIP, Lilly also filed the original application that issued as the ’826 patent, entitled “Method of Treating Tumors in Mammals with 2’,2’-Difluoronucleosides.”

In 2006, generic drug manufacturer Sun Pharmaceutical Industries, Ltd. (“Sun”) filed an ANDA with the FDA seeking approval to market a generic version of Lilly’s Gemzar® and certified that both the ’614 and ’826 patents were invalid or not infringed. On November 29, 2007, Sun filed a DJ action against Lilly in the Eastern District of Michigan for invalidity and noninfringement, and Lilly counterclaimed for infringement of the ’614 and ’826 patents. On August 17, 2009, the district court granted Sun’s motion for partial SJ that the asserted claims of the ’826 patent were invalid for obviousness-type double patenting over the earlier ’614 patent. Lilly appealed this ruling to the Federal Circuit.

On appeal, the Federal Circuit relied on its prior obviousness-type double patenting decisions in Geneva Pharmaceuticals, Inc. v. GlaxoSmithKline PLC, 349 F.3d 1373 (Fed. Cir. 2003), and Pfizer, Inc. v. Teva Pharmaceuticals USA, Inc., 518 F.3d 1353 (Fed. Cir. 2008). The Federal Circuit noted that in both Geneva and Pfizer, it found claims of a later patent invalid for obviousness-type double patenting “where an earlier patent claimed a compound, disclosing its utility in the specification, and a later patent claimed a method of using the compound for a use described in the specification of the earlier patent.” Slip op. at 7. The Court then considered whether the rationale of Geneva applied to single or multiple utilities. The Court noted that although Geneva only disclosed a single use for the claimed compound, the reasoning and holding of Geneva were not so limited. The Federal Circuit indicated that Pfizer disclosed more than one utility for the claimed compound—inflammation and inflammation-associated disorders— and that Pfizer invalidated the claims in the later patent that were separately directed to these multiple uses.

The Federal Circuit further stated that the “Pfizer decision shows that obviousness-type double patenting encompasses any use for a compound that is disclosed in the specification of an earlier patent claiming the compound and is later claimed as a method of using that compound.” Id. at 10. As a result, the Federal Circuit concluded that its obviousness-type double patenting analysis extends to any and all such uses disclosed in the specification of the earlier patent. Because the ’614 patent described the originally disclosed antiviral utility and also contained the one paragraph mentioning the anticancer use that was added in the CIP, the Federal Circuit held the ’826 patent, which claimed the method of using gemcitabine to treat cancer, invalid for double patenting.

Lilly’s primary argument on appeal was that the double patenting analysis of Geneva and Pfizer did not apply to its later ’826 patent claims reciting a method of using gemcitabine for cancer treatment because the original ’883 application for the ’614 patent did not contain any mention of the anticancer utility. In its briefs and at oral argument, Lilly argued that under Geneva, courts need to assess whether a compound and the utility necessary to make that compound patent eligible under 35 U.S.C. §§ 101 and 112 are being claimed in separate patents. Because the compound claims of the ’614 patent were entitled to their original filing date under 35 U.S.C. § 120, the district court should have examined the original application to see what utility was necessary to make gemcitabine patent eligible under §§ 101 and 112. Because the anticancer use was not mentioned in the original application, as it had not yet been invented, it could not be the utility necessary to patent the compound claim, and Geneva double patenting thus could not apply.

The Federal Circuit rejected Lilly’s argument that the district court should have evaluated the ’614 patent’s claim to gemcitabine based on the specification that existed as of the undisputed effective filing date of the ’614 patent (the original ’883 application). The Federal Circuit instructed that under its claim construction precedent, claim terms need to be construed in light of the entirety of the patent, including its specification, and that the specification to be consulted is that of the issued patent, not the original application.