Cephalon sues Watson over Fentora patent

NEW YORK Drug maker Cephalon alleges that Watson infringed on its patent by developing a generic equivalent to its drug, Fentora.

Fentora (fentanyl citrate) is used to treat pain in cancer patients and received approval from the Food and Drug Administration in September 2006.

Watson applied for FDA approval of its generic version in April. In response, Cephalon filed a lawsuit in the U.S. District Court for the District of Delaware on June 2, asserting that Watson had infringed on patents ‘604 and ‘590, both of which expire in 11 years.

Fentora recorded sales of $135 million in 2007.

The FDA has, however, granted approval for Watson’s application for a generic version of KV Pharmaceutical’s Micro-K Extencaps in 600 mg and 750 mg doses.

The company that is now Wyeth sold global rights and the trademark for Micro-K to KV for $36 million in 1999. Micro-K had sales of $80 between March 2007 and March 2008, according to IMS Health data.