Bloomberg Law
Sept. 29, 2022, 1:19 PM

Merck Fends Off Patent Challenge to Diabetes Treatment (1)

Samantha Handler
Samantha Handler

Merck Sharp & Dohme Corp. crushed a patent challenge from generic drugmaker Mylan Pharmaceuticals Inc., successfully defending its branded diabetes treatment Janumet XR at the Federal Circuit.

Merck had sued more than a dozen generic makers, including Mylan, accusing them of infringing its US Patent No. 7,326,708.

After Mylan and others challenged the validity of the patent, the US Court of Appeals for the Federal Circuit, in a precedential ruling Thursday, affirmed that the patent’s claims weren’t invalid as anticipated or obvious over previous inventions. The appeals court ruling will likely be a boost for Merck’s bid against the generic drug makers.

Merck showed enough evidence that a skilled expert in the field wouldn’t have thought of the invention based on previous treatments that were already publicly disclosed, the Federal Circuit ruled.

Janumet XR is used to treat Type 2 diabetes. It comes in the form of a tablet that contains the chemical compound sitagliptin and extended metformin.

Merck had sued at least 14 drug companies for infringement after the firms tried to sell generic versions of the treatment. The companies then raised questions about the validity of Merck’s patent at the Patent Trial and Appeal Board, alleging that an earlier international patent application also disclosed the form of sitagliptin claimed in the ‘708 patent.

After a bench trial in September in the US District Court for the Northern District of West Virginia, a judge found that Mylan infringed Merck’s patent.

The Federal Circuit agreed with the board’s finding that Mylan failed to show the particular form of sitagliptin was already disclosed in the earlier application.

Attorneys for Mylan and Merck didn’t immediately respond to requests for comment.

Judge Alan D. Lourie wrote the opinion. Judges Jimmie V. Reyna and Kara F. Stoll also served on the panel.

Katten Muchin Rosenman LLP represents Mylan. MoloLamken LLP and Williams & Connolly LLP represents Merck.

The case is Mylan Pharmaceuticals Inc., Merck Sharp & Dohme Corp., Fed. Cir., No. 21-2121, 9/29/22.

To contact the reporter on this story: Samantha Handler in Washington at

To contact the editors responsible for this story: Adam M. Taylor at; Jay-Anne B. Casuga at