Depomed, Inc., a specialty pharmaceutical company, announced that it has filed a lawsuit in the United States District Court for the District of New Jersey against Sun Pharmaceutical Industries, Inc.(Sun), for infringement of the patents listed in the Orange Book for Depomed's 500 mg and 1000 mg Glumetza (metformin hydrochloride extended release tablets).

The lawsuit is in response to an Abbreviated New Drug Application (ANDA) filed by Sun with the US Food and Drug Administration (FDA) regarding Sun's intent to market generic versions of the 500mg and 1000mg strengths of Glumetza prior to the expiration of the five listed US patents:  6,340,475, 6,488,962, 6,635,280, 6,723,340, and 7,780,987.   Depomed is also asserting US patent 7,736,667 in the lawsuit.

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

"Depomed will continue to vigorously enforce its intellectual property rights with respect to our Glumetza products," commented Matthew M. Gosling, Depomed's senior vice president and general counsel.