* Cephalon says Sandoz infringes two patents
* Fentora used to treat pain in cancer patients
* Sandoz has no immediate comment
Sept 16 Cephalon Inc CEPH.O on Friday sued Novartis AG's NOVN.VX Sandoz drug unit, accusing it of trying to infringe two patents related to its Fentora drug that treats pain in adults who have cancer.
In a complaint filed in the U.S. District Court in Wilmington, Delaware, Cephalon said Sandoz has applied with U.S. regulators to sell fentanyl citrate buccal tablets, a generic version of Cephalon's drug.
Cephalon said it advised Sandoz in June that the generic version would infringe two patents held by Cima Labs Inc, a unit of Frazer, Pennsylvania-based Cephalon. Cima is also a plaintiff in the case.
Sandoz nonetheless "has made, and continues to make, substantial preparation" to sell the generic version in the United States," and Cephalon and Cima will be "irreparably harmed" if this were to continue, the complaint said.
The lawsuit seeks a permanent halt to any infringement, monetary damages and other remedies.
A Sandoz spokeswoman had no immediate comment. The company is based in Princeton, New Jersey. Novartis is based in Basel, Switzerland.
Sales of Fentora totaled $97.8 million from January to June, accounting for 36 percent of Cephalon's pain medication sales and 7 percent of its total sales.
In February, Cephalon sued Mylan Inc (MYL.O) over that company's attempt to sell a generic version of Fentora, a regulatory filing shows.
Israel's Teva Pharmaceutical Industries Ltd (TEVA.TA) agreed in May to buy Cephalon for about $6.8 billion. [ID:nSGE741016] That purchase has yet to receive U.S. regulatory approval.
The case is Cephalon Inc et al v. Cima Labs Inc, U.S. District Court, District of Delaware, No. 11-00821. (Reporting by Jonathan Stempel in New York, editing by Dave Zimmerman)