Classen Immunotherapies, Inc. v. Elan Pharms., Inc., (Fed. Cir. May 13, 2015)

Affirming the U.S. District Court for the District of Maryland, the U.S. Court of Appeals for the Federal Circuit recently held the “safe harbor” provision of 35 U.S.C. § 271(e)(1) exempted infringement of Elan Pharmaceuticals’ post-approval clinical study and supplemental new drug application (sNDA) for its muscle relaxant, Skelaxin® (metaxalone). Classen Immunotherapies, Inc. v. Elan Pharms., Inc., 2015 WL 2216154 (Fed. Cir. May 13, 2015)

Classen sued Elan for infringement of U.S. Patent 6,584,472 (the ‘472 patent), which claims a method for accessing and analyzing data on a commercially available drug to identify a new use of that drug, and then commercializing that use. Elan conducted a post-approval bioavailability (BA) study on the food effects of Skelaxin. The results of the study showed the BA of Skelaxin increased when taken with food. Elan submitted a citizen petition asking the U.S. Food and Drug Administration (FDA) to require abbreviated new drug application (ANDA) filers to show both fed and fasting data and, at the same time, submitted an sNDA requesting a revision to Skelaxin’s label.

Classen attempted to expand its earlier victory at the Federal Circuit arguing that under Classen Immunotherapies, Inc. v. Biogen IDEC, 659 F.3d 1057 (Fed. Cir. 2011) Elan’s BA study, and subsequent FDA submission, fell outside the scope of § 271(e)(1)’s safe harbor, because Elan’s studies were “merely routine post-approval reporting to the FDA.” The Federal Circuit disagreed. The court reasoned that, after initial approval of a drug, a manufacturer may perform additional studies to support FDA approval of labeling changes for its approved products. In this case, Elan initiated its own clinical trials in response to the FDA proposal to re-designate metaxalone from “non-bioproblem” to “bioproblem.” Elan then submitted its results to support its proposed revision to the Skelaxin label. The Federal Circuit analogized these post-approval studies to pre-approval studies conducted to gain initial approval. In these circumstances, the court held that post-approval studies were exempt from infringement liability, because these activities “were anything but routine post-approval reporting,” but rather “necessary” for the approval of Skelaxin.

Classen next argued that Elan infringed the ‘472 patent when the company used the BA study data to file patent applications and sold Skelaxin with that data in the revised label. The Federal Circuit rejected the broader proposition, holding that subsequent disclosure or use of information obtained from an exempt post-approval clinical study, even if not used for regulatory approval, does not cause the clinical study to lose its exemption, provided that “the subsequent disclosure or use is itself not an act of infringement.”

The Federal Circuit remanded, because the specific questions of whether infringement occurred when Elan 1) filed patent applications and 2) sold Skelaxin with the revised labels that included the new BA data were not addressed by the district court. In dicta, the court set forth a specific and detailed road map, effectively guiding the district court to reject Classen’s infringement arguments. First, the court stated that filing a patent application is generally not an infringement, because it is not the making, using, offering to sell, selling or importing of an invention. Second, the court stated that placing information which has been submitted to the FDA on a product label after FDA approval is generally not infringement, because the information obtained from exempt activities does not cease to be exempt after approval of the sNDA. The court did note, however, that pharmaceutical patents claiming methods of treatment might still be infringed by information from exempt activities appearing on a product label. However, because the ‘472 patent is not directed to a pharmaceutical method of treatment, the court did not need to resolve that question.