MSD prevails in diabetes drug dispute with Mylan

MSD, known as Merck in the US and Canada, has won against a case concerning branded diabetes treatment Janumet XR at the US Court of Appeals for the Federal Circuit.

The pharma company had sued Mylan along with other generic drug markers over their alleged infringement of its US Patent No. 7,326,708.

After the generic drug companies sought an inter partes review, the US Patent Trial and Appeal Board delivered its decision in favour of the pharmaceutical company in May.

In a precedential ruling this week, the Federal Circuit, also upheld the patent’s claims as valid and not anticipated or obvious over previous inventions.

Mylan, which is now a part of Viatris, had appealed from the final written decision of the US Patent and Trademark Office’s Patent Trial and Appeal Board (PTAB) holding that it failed to show that claims 1–4, 17, 19, and 21–23 of the ‘708 patent were anticipated or would have been obvious over the cited prior art at the time the alleged invention was made.

The ’708 patent describes sitagliptin dihydrogenphosphate (sitagliptin DHP), which can be used for treating non-insulin-dependent (Type 2) diabetes.

This week, the Federal Circuit  agreed with MSD that the board’s decision was supported by substantial evidence.

“The key term here is ‘limited’,” said the court.

“As Merck asserted, and as the board considered, the list of 33 compounds, with no direction to select sitagliptin from among them, plus the eight “pharmaceutically preferred” acids and various stoichiometric possibilities, results in 957 salts, some of which may not exist.”

The court also found that the board did not err in its evaluation of purported objective indicia of nonobviousness.

“Although the board did not consider in detail the alleged unexpected properties of the claimed crystalline monohydrate of claim 4, the board stated that such unexpected results served as further evidence undermining Mylan’s challenge…”

The court concluded that it had considered Mylan’s remaining arguments, but found them unpersuasive.

“The Board’s decision was supported by substantial evidence and not erroneous as a matter of law. For the foregoing reasons, the decision of the Board is affirmed,” it said.

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