A new history and discussion of 180-day exclusivity.

Congress created 180-day exclusivity for generic drug applicants in the 1984 Hatch-Waxman amendments to the Federal Food, Drug, and Cosmetic Act (FDCA) and amended the provision substantially in the Medicare Prescription Drug, Improvement, and Modernization Act of 2003 (MMA). The fundamental goal behind 180-day exclusivity was to provide an incentive for generic drug applicants to challenge innovator patents, and the core of the concept--as it has been applied by the Food and Drug Administration (FDA) and the courts--is that the first generic drug applicant to challenge an innovator's patent is entitled to six months of exclusivity against subsequent patent challengers for the same innovator drug. 180-day exclusivity is governed by sections 505(j)(5)(B)(iv) and 505(j)(5)(D) of the FDCA. In this article, the authors provide a comprehensive resource on 180-day exclusivity for old abbreviated new drug applications (ANDAs) (but less detail in some places where the 2007 article may be referenced) but focus more discussion on the new provisions as well as some policy and legal issues related to 180-day exclusivity that have not previously addressed.