BRIEF—Another Merck win in sitagliptin patent lawsuit

The Court of Appeals for the Federal Circuit ruled in favor of Merck & Co in a patent challenge brought by Mylan Pharmaceuticals (now Viatris) related to sitagliptin dihydrogen phosphate, an active ingredient in Januvia (sitagliptin), Janumet (sitagliptin and metformin hydrochloride) and Janumet XR (sitagliptin and metformin hydrochloride extended-release).

On May 7, 2021, the Patent Office issued a decision in Merck’s favor, finding all challenged claims valid. Viatris appealed that decision to the Court of Appeals for the Federal Circuit, which today affirmed the decision.

Januvia, Janumet and Janumet XR together pulled in sales of $1.23 billion in the second quarter of this year.

Viatris had previously challenged validity of the patent in a case filed in the US District Court for the Northern District of West Virginia. The District Court ruled in favor of Merck in a decision dated September 21, 2022.