Watson Pharmaceuticals, Inc. has confirmed that its
subsidiary, Watson Laboratories, Inc. – Florida,
filed an Abbreviated New Drug Application (ANDA) with the 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.