Purdue Pharma Loses Appeal on Intermezzo Patent

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By Dana A. Elfin

Jan. 8 — In a loss for drugmaker Purdue Pharmaceutical Products LP, a federal appeals court Jan. 8 affirmed a district court's ruling that a patent covering Purdue's sleep disorder drug Intermezzo (zolpidem tartrate) was invalid for obviousness (Purdue Pharmaceutical v. Actavis Elizabeth LLC, Fed. Cir., No. 15-01659, nonprecedential, 1/8/16).

In the unsigned, nonprecedential disposition issued without an opinion, the U.S. Court of Appeals for the Federal Circuit affirmed a March 2015 ruling from Judge Jose L. Linares of the U.S. District Court for the District of New Jersey, in which Linares concluded that the asserted claims of three of Purdue's patents on Intermezzo were invalid (13 PLIR 457, 4/3/15).

Intermezzo, sold by Purdue Pharma, is used to treat insomnia when middle-of-the-night wakening is followed by difficulty returning to sleep.

Linares's ruling covered three Purdue patents: U.S. Patent Nos. 8,242,131 (the ‘131 patent); 8,252,809 (the ‘809 patent); and 7,682,628 (the ‘628 patent). But Purdue only appealed Linares's ruling on the ‘131 patent to the Federal Circuit.

Oral argument in the Federal Circuit appeal was held Jan. 4 in front of Circuit Judges Alan D. Lourie, Timothy B. Dyk and Todd M. Hughes.

Thorough Opinion Below

Jake M. Holdreith of Robins Kaplan LLP in Minneapolis, who argued the appeal on behalf of all the defendants-appellees, told Bloomberg BNA Jan. 8 that he is “happy about how quickly the appeals court ruled” in the case.

The fact that the lower court issued a “really thorough and careful opinion” likely made it easy for the appeals court to resolve the appeal promptly, Holdreith said.

Novel Labs Eligible for Generic Exclusivity on Intermezzo

The ruling affirming the ‘131 patent's invalidity is particularly welcome news for generic drug company Novel Laboratories Inc., because it was the first company to file a substantially complete abbreviated new drug application containing a paragraph IV certification, which challenges the patents on the drug, for Intermezzo with the Food and Drug Administration. This means Novel is eligible for 180 days of exclusivity on the generic, once it receives final marketing approval from the FDA.

In addition to Novel, the other generic drug companies in the litigation include Actavis Elizabeth LLC, Dr. Reddy's Laboratories Inc., Dr. Reddy's Laboratories Ltd., Par Pharmaceutical Inc. and TWi Pharmaceuticals Inc.

In the district court ruling affirmed by the Federal Circuit, Linares found that all of the defendants in the patent litigation infringed the ‘131 patent, that Novel infringed the ‘628 patent, and that both Novel and Dr. Reddy's infringed the ‘809 patent, but that none of the patents were valid.

The ‘131 patent, which issued in August 2012, covers methods of treating middle-of-the-night insomnia. It is set to expire in August 2029. The ‘628 patent, which issued in March 2010, covers compositions for delivering hypnotic agents across the oral mucosa and methods of use thereof, and is set to expire February 2025. The ‘809 patent, which issued in August 2012, covers compositions for treating insomnia. It is also set to expire in February 2025.

Two of the generic companies involved in the litigation, Taipei, Taiwan-based TWi and Woodcliff Lake, N.J.-based Par, didn't participate in the trial at the district court stage or in the appeal to the Federal Circuit. Instead, they entered into stipulations with Purdue staying the claims and counterclaims over Intermezzo pending the final resolution of Purdue's claims against all the remaining defendants in the Intermezzo action.

The case dates back to August 2102, when Purdue and co-plaintiff Transcept Pharmaceuticals, Inc. (now Paratek Pharmaceuticals, Inc.), filed the initial patent infringement suit against the generic drug companies. Paratek, based in Pt. Richmond, Calif., is a specialty drug company, and Intermezzo is its first FDA-approved product.

Jake M. Holdreith, of Robins Kaplan LLP in Minneapolis argued on behalf of all the defendants-appellees: Somerset, N.J.-based Novel, Elizabeth, N.J.-based Actavis Elizabeth LLC, a subsidiary of Irish company Actavis plc, and India-based Dr. Reddy's.

Christopher Neil Sipes, of Covington & Burling LLP in Washington, D.C., argued for plaintiffs-appellants, including Stamford, Conn.-based Purdue Pharmaceutical Products L.P., Purdue Pharma L.P., Transcept Pharmaceuticals, Inc. (now Paratek Pharmaceuticals, Inc.).

To contact the reporter on this story: Dana A. Elfin in Washington at delfin@bna.com

To contact the editor responsible for this story: Brian Broderick at bbroderick@bna.com