Watson Laboratories sued in connection with filing of ANDA for generic version of Rapamune tablets

Watson Pharmaceuticals, Inc. (NYSE: WPI) today confirmed that its subsidiary, Watson Laboratories, Inc. - Florida, has been sued by Pfizer Inc. and Wyeth Pharmaceuticals Inc. in connection with the filing of Watson's Abbreviated New Drug Application (ANDA) for sirolimus tablets in the 1 mg and 2 mg strengths. Watson's ANDA is for a generic equivalent of Wyeth's Rapamune® tablets product. The suit was filed on April 28, 2010 in the United States District Court for the District of Delaware.

Pursuant to the Hatch-Waxman Act, Watson previously notified Pfizer and Wyeth that Watson's ANDA contains a paragraph IV certification asserting that U.S. Patent No. 5,100,899 is invalid, unenforceable and /or will not be infringed by the commercial manufacture, use or sale of the drug products described in Watson's ANDA.  Based on available information, Watson believes it may be a "first applicant" to file an ANDA for the 1 mg and 2 mg generic version of Rapamune® and, should its ANDA be approved, may be entitled to 180 days of generic market exclusivity for those strengths.

Rapamune® (sirolimus) tablets are indicated for the prophylaxis of organ rejection in patients aged 13 years or older receiving renal transplants.  For the twelve months ending February 2010, Rapamune® had total U.S. sales of approximately $210.5 million according to IMS Health data.