Elan Study on Skelaxin Doesn't Infringe Classen Patent

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By Dana A. Elfin and Tony Dutra

Sept. 28 — Elan Pharmaceuticals Inc. isn't subject to charges that it infringed a Classen Immunotherapies Inc. patent in submitting study data on its Skelaxin muscle relaxant ( Classen Immunotherapies, Inc. v. Elan Pharms., Inc. , 2016 BL 318007, D. Md., No. 1:04-cv-03521-RDB, 9/27/16 ).

The U.S. District Court for the District of Maryland ruled Sept. 27 that Elan's provision of information on the safety and efficacy of the underlying drug, metaxalone, to the Food and Drug Administration falls within the “safe harbor” of the Hatch-Waxman Act.

The safe harbor is important to companies on both sides of patent litigation because it can exempt from liability infringing activity that's “reasonably related to the development and submission of information” to the FDA.

Brand and generic manufacturers have been battling over the limits of the safe harbor provision for the past eight years, resulting in arguably conflicting decisions by the U.S. Court of Appeals for the Federal Circuit, particularly regarding activities conducted after FDA approval.

Classen's 12-year-old case is likely ended with the decision, as the Federal Circuit, in effect, guided the district court to this conclusion.

Source Material:

Fed. Cir. decision: 786 F.3d 892 (May 13, 2016)

U.S. Patent:No. 6,584,472

Post-Approval Actions Covered by Safe Harbor

The Hatch-Waxman safe harbor provision in question, 35 U.S.C. §271(e)(1) , provides an exception for otherwise infringing acts, usually by generic makers. But under Federal Circuit law, it can extend to brand name makers as well.

Here, the FDA approved Elan's new drug application (NDA) for Skelaxin in 2001. Responding to a third party's data, though, the FDA sought Elan's feedback on a proposal to change the drug label. Elan conducted a clinical trial to characterize the effect of food on the absorption of metaxalone and submitted that information to the FDA to revise Skelaxin's product label and to propose changes to the approval requirements for generic versions of the drug.

Classen asserted U.S. Patent No. 6,584,472 , alleging infringement by the study, the information that would be on the label and Elan's activities related to filing for new patents in light of what it learned in the study.

In 2012, the district court granted summary judgment in favor of Elan under the safe harbor, not reaching decisions on infringement or validity. The Federal Circuit affirmed and remanded only because the original district court opinion didn't say enough about whether some of Elan's activities met the “reasonably related” characterization. Classen Immunotherapies v. Elan Pharms., Inc., 786 F.3d 892, 114 U.S.P.Q.2d 1920 (Fed. Cir. 2015) (13 PLIR 731, 5/22/15).

Following Federal Circuit's Script

On remand, Judge Richard D. Bennett quoted extensively from “observations of the record” in the Federal Circuit's opinion that detailed how it expected the district court to assess those other activities.

Classen argued that “reanalyzing the clinical data to identify patentable information and filing patent applications” is aimed at commercialization and so is outside of the safe harbor. But Bennett simply restated the appeals court's caution that filing patent applications is not a commercial event.

He also rejected Classen's contention that a revised Skelaxin label was integral to making and selling the product. Bennett said that the safe harbor can apply to the disclosure and use of clinical study results “even for purposes other than regulatory approval.” Elan's use of the data here was far less “commercial” in nature than prior cases that have invoked the safe harbor, he said.

The judge further said that even if Classen's claims weren't barred as a matter of law, it still hadn't raised a genuine issue of material fact regarding infringement.

“Here, with discovery long complete and this case having worn on for nearly twelve years, Classen has produced no evidence of Elan’s alleged reanalysis of the data for commercial purposes so as to raise a genuine issue of material fact regarding Elan’s infringement,” Bennett said.

Elan is now part of Dublin-based Perrigo Co. plc. Bloomberg BNA contacted Perrigo's U.S. subsidiary, Allegan, Mich.-based Perrigo Co., Sept. 28, but the company declined to comment on the ruling. Bloomberg BNA also contacted Baltimore-based Classen but no one was available to comment.

DNL Zito, Washington, represented Classen. Finnegan, Henderson, Farabow, Garrett & Dunner LLP, Washington, represented Elan.

To contact the reporters on this story: Dana A. Elfin in Washington at delfin@bna.com , and Tony Dutra in Washington at adutra@bna.com

To contact the editor responsible for this story: Mike Wilczek at mwilczek@bna.com

For More Information

Text of the decision is at http://src.bna.com/iX9.

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