Mylan Inc. (MYL) said it is seeking to overturn a decision by the U.S. Food and Drug Administration that awarded Teva Pharmaceutical Industries Ltd. (TEVA, TEVA.TV) exclusivity for its generic version of Cephalon Inc.'s wakefulness drug Provigil.

The generic drug maker said Thursday it has filed a lawsuit against the FDA in the U.S. district court for the District of Columbia. Mylan is seeking an immediate court order entitling it to exclusivity as well as immediate approval for its abbreviated new drug application.

Mylan alleges Teva did not maintain valid certifications as a result of its acquisition last year of Cephalon and thus is not entitled to exclusivity based on patent certifications. Mylan also alleges that the FDA should have found Mylan as the sole first filer on one of the patents for Provigil.

Earlier Thursday, Teva said the FDA has decided that Teva is the sole first-to-file for both of Provigil's patents, which entitled the company to 180-day exclusivity. The FDA decided that Cephalon's launch of generic Provigil on March 29 triggered the exclusivity.

In October, the Federal Trade Commission required Teva to sell the rights and assets related to a generic cancer pain drug and a generic muscle relaxant in connection with Teva's acquisition of Cephalon. The FTC agreement also required Teva to enter a supply agreement that allows a competing firm, Par Pharmaceuticals Inc. (PRX), to sell a generic version of Provigil in 2012.

Teva expects Par Pharmaceuticals to launch a second generic product on April 6.

Mylan shares slipped 1.8% to $22.74 in recent trading. The stock is up 5.9% so far this year.

 
   -By Nathalie Tadena, Dow Jones Newswires; 212-416-3287; nathalie.tadena@dowjones.com