Impax Sued by Teva’s Cephalon Over Fentora Pain Drug Patents

Nov. 21 (Bloomberg) -- Impax Laboratories Inc. was sued by the Teva Pharmaceutical Industries Ltd. unit Cephalon Inc., alleging infringement of four U.S. patents for the drug Fentora, used to treat pain associated with cancer.

Cephalon, based in Frazer, Pennsylvania, contends Hayward, California-based Impax is planning to market a generic version of Fentora in violation of the patent protections, according to papers filed Nov. 18 in federal court in Wilmington, Delaware.

“Impax Laboratories was aware of the patents,” and “plaintiffs will be irreparably harmed” unless stopped by court order, Cephalon lawyers said in the complaint.

Cephalon is seeking a judgment of infringement, unspecified damages and an injunction to stop Impax’s generic sales.

In a statement today, Impax acknowledged the challenge and said U.S. sales of the drug were about $159 million for the year ending in September.

Once its application is approved by the U.S. Food and Drug Administration, Impax “intends to commercialize the drug,” it said in the statement.

Teva, based in Petach Tikvah, Israel, the world’s largest generic-drugmaker, acquired Cephalon last month in a $6.8 billion deal.

The case is Cephalon Inc. v. Impax Laboratories Inc., 11-cv-1152, U.S. District Court, District of Delaware (Wilmington).

To contact the reporter on this story: Phil Milford in Wilmington, Delaware, at

To contact the editor responsible for this story: Michael Hytha at