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 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 and patent holder.
On July 25, 2008, Brigham and Women’s Hospital, NPS Pharmaceuticals and Amgen filed suit in the US 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.