Watson files generic Exalgo ANDA, confirms patent challenge from Mallinckrodt

Watson Pharmaceuticals, Inc. (NYSE: WPI) today confirmed that its subsidiary, Watson Laboratories, Inc. – Florida, filed an Abbreviated New Drug Application (ANDA) with the U.S. Food and Drug Administration (FDA) seeking approval to market Hydromorphone Hydrochloride Extended-release Tablets, 8 mg, 12 mg, and 16 mg.  Watson's Hydromorphone Hydrochloride Extended-release Tablets are a generic version of Mallinckrodt Inc.'s Exalgo™ tablets, which are indicated for once daily administration for the management of moderate to severe pain in opioid tolerant patients requiring continuous, around-the-clock opioid analgesia for an extended period of time.

Mallinckrodt filed suit against Watson on December 10, 2010 in the United States District Court for the District of New Jersey seeking to prevent Watson from commercializing its product prior to the expiration of U.S. Patent No. 5,914,131.  Mallinckrodt's lawsuit was filed under the provisions of the Hatch-Waxman Act, resulting in a stay of final FDA approval of Watson's ANDA until April 29, 2013, or until final resolution of the matter before the court, whichever occurs sooner, subject to any other exclusivities.  

Based on available information, Watson believes it may be a "first applicant" to file an ANDA for the 8 mg, 12 mg, and 16 mg generic versions of Exalgo™ and, should its ANDA be approved, may be entitled to 180 days of generic market exclusivity.