Indian Court Finds in Favor of Merck in Sitagliptin Dispute
Generics maker Glenmark might have infringed on Merck’s Indian patent covering type II diabetes drugs Januvia and Janumet, the Delhi High Court in India said recently in an interim ruling.
Merck filed for a sitagliptin patent in the U.S. in 2002 and then in India in 2004. Glenmark was granted a U.S. patent 10 years later for R-sitagliptin and its pharmaceutically acceptable salts. Merck filed an injunction against Glenmark in 2013, claiming that the company’s drugs Zita and Zitamet infringed on its sitagliptin patent.
The case turns on whether a specific salt form of sitagliptin, called SPM, was adequately disclosed in Merck’s patent application for Januvia (sitagliptin) and Janumet (sitagliptin and metformin HCl).
Merck also argues that SPM should be covered in the patent on grounds of obviousness.
Glenmark had tried to claim that there are potentially thousands of salt forms of sitagliptin and that Merck’s patent should be invalid, as it might bar other drugmakers from creating thousands of salt forms of sitagliptin. It also tried to claim that it had manufactured SPM without using sitagliptin as its base.
The court was unimpressed with these arguments, saying that Merck’s drugs control blood sugar in novel ways and that Glenmark’s Zita and Zitamet use compounds that may be covered by Merck’s patent.
The Delhi High Court’s decision differs from a previous single judge’s ruling that found that sitagliptin and SPM were different enough that the company’s patent cannot cover both of them. The Delhi High Court recognized, however, that there is room for debate on this issue. The case will go back to the single judge for a hearing on April 10.
Read the March 20 decision at www.fdanews.com/03-24-15-Merckcase.pdf. — Lena Freund