Allergan Confirms Generic Noxafil Patent Challenge

Allergan has filed an Abbreviated New Drug Application (ANDA) with FDA seeking approval to market Posaconazole Delayed-Release Tablets, 100 mg. Allergan's ANDA product is a generic version of Merck's Noxafil, which is an antifungal agent indicated for prophylaxis of invasive Aspergillus and Candida infections in patients, 13 years of age and older, who are at high-risk of developing these infections due to being severely immunocompromised, such as hematopoietic stem cell transplantation recipients with graft-versus-host disease or those with hematologic malignancies with prolonged neutropenia from chemotherapy.

Merck Sharp & Dohme Corp. filed suit against Allergan on 6 August 2015 in the US District Court for the District of New Jersey seeking to prevent Allergan from commercializing its ANDA product prior to the expiration of US Patent No. 5,661,151. The lawsuit was filed under the provisions of the Hatch-Waxman Act, resulting in a stay of final FDA approval of Allergan's ANDA for up to 30 months from the date the plaintiffs received notice of Allergan's ANDA filing or until final resolution of the matter before the court, whichever occurs sooner, subject to any other exclusivities.

Based on available information, Allergan believes it may be a "first applicant" to file an ANDA for the generic version of Noxafil and, should its ANDA be approved, may be entitled to 180 days of generic market exclusivity.

For the 12 months ending 30 June 2015, Noxafil had global sales of approximately $143.6 million, according to IMS Health data.