Barr confirms Xopenex patent challenge

Barr Pharmaceuticals, Inc. has confirmed that its subsidiary, Barr Laboratories, Inc., has initiated a challenge of the patents listed by Sepracor Inc. in connection with its Xopenex (Levalbuterol Hydrochloride) 0.31mg/3mL, 0.63mg/3mL and 1.25mg/3mL.

Barr filed its Abbreviated New Drug Application (ANDA) containing a paragraph IV certification for a generic Xopenex product with the U.S. Food & Drug Administration (FDA) in March 2007, and received notification of the application's acceptance for filing in May 2007. Following receipt of the notice from the FDA, Barr notified Sepracor, the New Drug Application (NDA) and patent owner.

On July 13, 2007, Sepracor announced it had filed suit in the U.S. District Court 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.

Xopenex(R) (Levalbuterol Hydrochloride) 0.31mg/3mL, 0.63mg/3mL and 1.25mg/3mL, is indicated for the treatment or prevention of bronchospasm in adults, adolescents, and children 6 years of age and older with reversible obstructive airway disease. The product had sales of approximately $609 million in the U.S., based on IMS sales data for the twelve months ended May 2007.