Merck wins ruling upholding diabetes-treatment patent at U.S. appeals court

Signage is seen at the Merck & Co. headquarters in Kenilworth, New Jersey, U.S. REUTERS/Andrew Kelly
  • Merck patent covers forms of Januvia, Janumet
  • Generic drugmaker Mylan loses bid to cancel patent

(Reuters) - A Merck Sharp & Dohme Corp patent related to its diabetes drugs Januvia and Janumet is valid, a U.S. appeals court said Thursday, rejecting a challenge to the patent by generic drugmaker Mylan Pharmaceuticals Inc.

Viatris Inc's Mylan failed to convince the U.S. Court of Appeals for the Federal Circuit that the patent was invalid based on an earlier patent and other publications.

Viatris and its attorney did not immediately respond to a request for comment. Merck said in a statement that it was pleased with the decision.

Sales of Januvia and Janumet topped $5.2 billion last year. A Merck annual report said its patents on the drugs will expire in January, but the patent at issue, on a salt form of the drugs' active ingredient, would keep generics in that form off the market until at least 2027.

Merck's February report said it had already settled disputes over the diabetes drugs with 21 other companies, allowing them to make generics starting in 2026.

Merck sued for patent infringement in West Virginia in 2019 after Mylan applied for U.S. Food and Drug Administration approval to make generic Januvia and Janumet. Mylan challenged the validity of parts of the patent at the U.S. Patent and Trademark Office.

The PTO's Patent Trial and Appeal Board was unconvinced by Mylan's argument that Merck's patent was invalid based on an earlier patent and other publications that supposedly disclosed the same form of the drugs.

A federal judge in West Virginia found last week that Mylan infringed the patent.

The Federal Circuit agreed with the board that the patent was valid on Thursday. It rejected Mylan's arguments that Merck's patent would have been obvious based on the earlier publications Mylan cited.

The case is Mylan Pharmaceuticals Inc v. Merck Sharp & Dohme Corp, U.S. Court of Appeals for the Federal Circuit, No. 21-2121.

For Mylan: Eric Werlinger of Katten Muchin Rosenman

For Merck: Jeffrey Lamken of MoloLamken

(NOTE: This story has been updated with comment from Merck.)

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Blake Brittain reports on intellectual property law, including patents, trademarks, copyrights and trade secrets. Reach him at blake.brittain@thomsonreuters.com