The FDA is pushing to expand the generic drug market by challenging a recent court decision providing two generic manufacturers with 180 days of market exclusivity for their version of the cholesterol-lowering drug Zocor, court filings show.

The agency filed a motion May 25 seeking expedited review of a federal district court's decision that Ivax Pharmaceutical Industries and Ranbaxy Laboratories have six months' exclusivity for a generic version of Merck's Zocor (simvastatin), arguing that providing exclusivity would hinder the broader generic market. Zocor is due to go off patent June 23. If Ivax and Ranbaxy prevail, other generic manufacturers will not be able to produce versions of Zocor until Dec. 23. The FDA filed its original appeal May 24.

"The sooner the court resolves the issue presented -- assuming the court does so in FDA's favor -- the sooner full generic competition can begin and the sooner the public can reap the benefit of full competition," the May 25 filing with the U.S. District Court for the District of Columbia says.

The agency also argues that greater certainty in how its statutory authority over drug patents applies helps the pharmaceutical industry "whose business plans depend on how the statutory provisions at issue are interpreted."

The issue in Ranbaxy Laboratories, et al. and Ivax Pharmaceuticals v. Leavitt is whether the FDA can delist a patent after a generic drug applicant has filed a new drug application, but before patent litigation begins. Doing so would deny the applicant the 180-day period of marketing exclusivity that the first generic applicant usually enjoys.

Under the Hatch-Waxman Amendments to the Federal Food, Drug, and Cosmetic Act (FDCA) the agency can grant generic market exclusivity to the first manufacturer to file a certification that its product will not infringe a brand manufacturer's patent. The period of exclusivity is meant to be an incentive for generic companies to file the application even though doing so will open them up to a patent infringement suit. (http://www.fdanews.com/did/5_105/)