Impax Laboratories, Inc. (NASDAQ:IPXL) today confirms that Pfizer Inc., Pharmacia & Upjohn Company LLC and Pfizer Health AB (collectively, "Pfizer") have filed suit for patent infringement against Impax in the United States District Court for the District of New Jersey in connection with Detrol® (tolterodine tartrate) immediate-release, 1 mg and 2 mg tablets.
Impax filed its Abbreviated New Drug Application (ANDA) containing a paragraph IV certification for a generic version of Detrol® with the U.S. Food & Drug Administration (FDA). Following receipt of the notice from the FDA that Impax's ANDA had been accepted for filing, Impax notified the New Drug Application holder and patent owner of its paragraph IV certification.
On May 31, Pfizer filed suit for patent infringement against Impax formally initiating the patent challenge process under the Hatch-Waxman Act.
Detrol® is indicated for the treatment of overactive bladder and urinary incontinence. According to Wolters Kluwer Health, U.S. sales of Detrol® immediate-release, 1 mg and 2 mg tablets were approximately $62 million for the 12 months ended March 2011.