Barr Pharmaceuticals, Inc. (BRL) confirmed that its subsidiary, Barr Laboratories, Inc., has initiated a challenge of the patents listed by Amgen Inc. in connection with its Sensipar tablets (cincalcet hydrochloride), 30mg, 60mg and 90mg.

Barr's Abbreviated New Drug Application (ANDA) containing a paragraph IV certification for a generic Sensipar product was received as acceptable for filing by the US Food & Drug Administration (FDA) on March 10, 2008, the first date the FDA could accept an ANDA with a paragraph IV certification for this product. 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 25, 2008, Brigham and Women's Hospital Inc., NPS Pharmaceuticals, Inc. and Amgen filed suit in the US 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.

Sensipar (cincalcet hydrochloride) had annual sales of approximately $377 million in the US, based on IMS sales data for the twelve month period ending May 2008.

Barr Pharmaceuticals, Inc. is a global specialty pharmaceutical company that operates in more than 30 countries worldwide and is engaged in the development, manufacture and marketing of generic and proprietary pharmaceuticals, biopharmaceuticals and active pharmaceutical ingredients.