Teva’s Cephalon Wins Ruling on Challenge to Amrix Patents

Cephalon Inc. (TEVA) won an appeals court ruling that could help it block generic versions of the muscle- relaxant Amrix.

The U.S. Court of Appeals for the Federal Circuit in Washington today said a trial judge erred in invalidating two patents on the medicine. Mylan Inc. (MYL) and Par Pharmaceutical Cos. (PRX), which won a patent challenge at the lower court, can seek victory on other grounds, including allegations of patent misuse and antitrust violations.

Cephalon, bought by Petah Tikva, Israel-based Teva Pharmaceutical Industries Ltd. last year, and partner Eurand NV (EURX) sought to block low-cost versions of the medicine from entering the market until the patents expire in 2023 and 2025. They cover a dosage form of a skeletal muscle relaxant and a method of relieving muscle spasms.

Mylan began selling generic Amrix in May 2011 after winning the ruling that the patents covered obvious variations of earlier known research. U.S. District Judge Sue Robinson ordered Mylan to hold off selling the drug until the appeals court ruling. The Federal Circuit said that sales ban will remain in effect until Robinson gets the case back.

Amrix generated $109 million in U.S. sales in 2010, before the generic versions entered the market.

The case is Eurand Inc. v. Mylan Pharmaceuticals Inc., 2011-1399 and 2011-1409, U.S. Court of Appeals for the Federal Circuit (Washington. The lower court case is Cyclobenzaprine Hydrochloride Patent Litigation, 09-2118, U.S. District Court, District of Delaware (Wilmington).

To see the patents, click: 7,387,793, 7,544,372.

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

To contact the editor responsible for this story: Bernard Kohn at bkohn2@bloomberg.net