Generic competition to Pozen's (Nasdaq: POZN) migraine drug Treximet will be held at bay for now.

A judge in the U.S. District Court for the Eastern District of Texas has granted a preliminary injunction that orders Par Pharmaceutical (NYSE: PRX) not to make or sell a generic version of Treximet, which is sold in the United States by drug partner GlaxoSmithKline (NYSE: GSK).

The judge's decision comes just in time for Chapel Hill, N.C.-based Pozen. The regulatory exclusivity on Treximet expired Friday, and barring the ruling, Par would have been free to enter the market with a generic.

The U.S. Food and Drug Administration approved Treximet in 2008 for the treatment of migraines. Treximet generated $15.4 million in 2010 royalty revenue for Pozen. Pozen on March 22 filed a preliminary injunction to prevent Par from launching its generic.

Pozen holds three patents on Treximet -- two that expire in 2017 and one that expires in 2025. Pozen has sued Par and three other generic makers -- Alphapharm, Teva Pharmaceuticals (Nasdaq: TEVA), and Dr. Reddy's Laboratories (NYSE: RDY) -- claiming that their generic products infringe on its three Treximet patents.

Teva was dismissed without prejudice from the consolidated litigation last April. The case against the other three defendants was tried before Judge Leonard Davis in the Eastern District of Texas last October. A decision is pending. The preliminary injunction remains in effect until a final decision from Judge Davis.

Pozen said in a statement that the company continues to believe that its patents covering Treximet are valid and enforceable, and that these beliefs will be upheld by the court.

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