July 6 (Bloomberg) -- Takeda Pharmaceutical Co. sued India’s Torrent Pharmaceuticals Ltd. to prevent it from selling a copy of the Actos diabetes pill in the U.S. until 2016.

Torrent, based in Ahmedabad, India, is seeking U.S. Food and Drug Administration approval to sell a copy of the medicine. Takeda, Asia’s biggest drugmaker, contends the versions would infringe six patents on the medicine and wants a court to block approval until they expire in 2016.

Actos is the world’s best-selling diabetes drug, responsible for 387 billion yen ($4 billion), or 25 percent, of Takeda’s sales for the year ended March 31. Last month, Takeda failed to gain FDA approval for another drug, called alogliptin, that the company is counting on to replace Actos revenue when generic competition begins as early as January 2011, when a patent on the drug expires.

The six patents in the complaint relate to ways to use the compound pioglitazone, the active ingredient in Actos, in combination with other medicines. Torrent’s proposed label wouldn’t restrict use of the generic drug, so “Torrent will be marketing pioglitazon with specific intent” to infringe the patents, Osaka-based Takeda said in the complaint, filed July 2 in federal court in New York.

In its FDA application, Torrent maintained that it would not infringe any valid and enforceable patent by selling a generic version of Actos. Under federal law, Takeda’s suit triggers an automatic 30-month period in which the FDA can’t approve Torrent’s application unless a judge rules in the generic-drug maker’s favor before then.

The case is Takeda Pharmaceutical Co. v. Torrent Pharmaceuticals Ltd., 09cv6051, U.S. District Court for the Southern District of New York (Manhattan).

To contact the reporter on this story: Susan Decker in Washington at sdecker1@bloomberg.net.

Last Updated: July 6, 2009 19:17 EDT