Watson challenges Pfizer's Pristiq patent

US generics drugmaker Watson Pharmaceuticals (NYSE: WPI) has confirmed that its subsidiary, Watson Laboratories, filed an Abbreviated New Drug Application with the US Food and Drug Administration seeking approval to market a generic version of pharma behemoth Pfizer’s (NYSE: PFE) Pristiq (desvenlafaxine succinate) extended-release tablets, 50mg and 100mg, which is indicated for the treatment of major depressive disorder (MDD) in adults.

Pfizer (and its Wyeth, Wyeth Pharmaceuticals units) and PF Prism CV filed suit against Watson on June 22 in the US District Court for the District of Delaware seeking to prevent Watson from commercializing its desvenlafaxine product prior to the expiration of US Patent No 6,673,838. The law suit was filed under the provisions of the Hatch-Waxman Act, resulting in a stay of final FDA approval of Watson's ANDA until August 29, 2015 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 generic version of Pristiq and, should its submission be approved, the company may be entitled to 180 days of generic market exclusivity.