Lupin Ltd, the fifth largest Indian pharma company with sales of over Rs 3,775 crore, and its wholly owned subsidiary Lupin Pharmaceutical, Inc, are facing a patent infringement lawsuit for Glumetza (metformin hydrochloride extended release tablets) by Depomed Inc, in the US District Court for the Northern District of California.

The lawsuit is in response to filing of ANDA by Lupin with the US FDA regarding marketing generic versions of 500mg and 1000mg strengths of Glumetza prior to the expiration of the four listed patents (Nos. 6,340,475; 6,488,962; 6,635,280; and 6,723,340).

Depomed has commenced the lawsuit within the 45 days required to automatically stay, or bar, the FDA from approving Lupin's ANDA for 30 months or until a district court decision that is adverse to the patents, whichever may occur earlier.

"We have full confidence in the intellectual property rights protecting our Glumetza products. We intend to vigorously defend and enforce our intellectual property rights, as we have in previous infringement actions," commented Matthew M Gosling, Depomed's vice president and general counsel.

Glumetza is approved for use in adults with type-2 diabetes and promoted by Santarus, Inc. in the United States. Depomed formulates its products and product candidates with its proven, proprietary Acuform drug delivery technology, which is designed to improve existing oral medications, allowing for extended, controlled release of medications to the upper gastrointestinal tract. Benefits of Acuform-enhanced pharmaceuticals include the convenience of once-daily administration, improved treatment tolerability and enhanced compliance and efficacy.