PAR PHARMACEUTICAL SUED OVER GENERIC RYTHMOL

Reliant Pharmaceuticals has filed a lawsuit against Par Pharmaceutical in response to Par's plan to market propafenone HCl capsules, a generic version of Rythmol SR extended-release capsules.

Rythmol is used to treat patients at risk for cardiovascular disease. Recent sales figures were not available.

The company filed the suit in the U.S. District Court for the District of Delaware after it received notification of Par's abbreviated new drug application (ANDA) seeking approval to sell a generic version of the drug in 325-mg doses prior to the expiration of the patent.

The company intends to "vigorously protect and defend its intellectual property rights against infringement," Reliant said.

The company is seeking a judgment of infringement against Par, payment for reasonable attorney's fees, a permanent injunction blocking sales of generic Rythmol prior to patent expiry and a court order that will allow FDA approval for the ANDA no earlier than the expiration date of the drug's patent.

In September, the FDA sent Reliant a warning letter cautioning it against making claims about Rythmol SR treating atrial fibrillation without mentioning any of the associated risks. The ads suggested the drug has a safety level among consumers higher than what has been demonstrated by certain clinical tests, the letter said.