On March 26, FDA issued a decision granting Teva 180-day exclusivity for generic versions of Merck's Cozaar® (losartan potassium) and Hyzaar® (losartan potassium and hydrochorothiazide). FDA appeared reluctant to grant exclusivity, because Merck requested that the single patent for Cozaar® and Hyzaar® be delisted, and the patent expired due to Merck's failure to pay maintenance fees--both usual circumstances where a first-to-file abbreviated new drug application (ANDA) applicant forfeits its 180-day exclusivity.
FDA reasoned that the D.C. Circuit's March 2, 2010 decision in Teva Pharms, USA, Inc. v. Sebelius mandated this outcome. The court found the Hatch-Waxman 2003 amendments "structurally" do not permit new drug application (NDA) holders to deprive first ANDA applicants from obtaining 180-day exclusivity by unilaterally delisting a patent. Similarly, FDA determined that just because a patent expires due to the NDA holder's unilateral decision to not pay maintenance fees, the first applicant should not be deprived from 180-day exclusivity.