Barr confirms Fentora tablet patent challenge

Barr Pharmaceuticals, Inc. has confirmed that its subsidiary, Barr Laboratories, Inc., has initiated a challenge of the patents listed by Cephalon, Inc. in connection with its Fentora(R) Tablets (fentanyl citrate buccal tablets), equivalent to fentanyl base 100 mcg, 400 mcg, 600 mcg and 800 mcg.

Barr filed its Abbreviated New Drug Application (ANDA) containing a paragraph IV certification for a generic Fentora product with the U.S. Food & Drug Administration (FDA) in February 2008. Following receipt of the notice from the FDA that Barr's ANDA had been accepted for filing, Barr notified the New Drug Application (NDA) and patent holder.

On July 22, 2008, Cephalon, Inc. and Cima Labs., Inc. filed suit in the U.S. District Court for the District of Delaware to prevent Barr from proceeding with the commercialization of its product. This action formally initiates the patent challenge process under the Hatch-Waxman Act.

Fentora (fentanyl citrate buccal tablets) had annual sales of approximately $142 million in the U.S., based on IMS sales data for the 12-month period ending May 2008.