May 14 (Reuters) - Pernix Therapeutics Holdings Inc said it would buy the U.S. marketing rights for a migrainetreatment developed by GlaxoSmithKline Plc and Pozen Inc for an upfront payment of $250 million.
Pernix's shares jumped as much as 42.5 percent in earlytrading on the Nasdaq.
The deal will nearly double Pernix's revenue by allowing itto expand its presence in the neurological market, the companysaid on Wednesday.
Pozen will get a warrant to purchase 500,000 Pernix shares,or about 1.3 percent of its outstanding stock, at Tuesday'sclosing price of $4.28.
The drug, Treximet, was approved by the U.S. Food and DrugAdministration in April 2008 to treat acute migraine attacks inadults.
Pernix plans to the expand the use of the drug for childrenand expects to file for regulatory approval by the end of theyear.
The company said the agreement is expected to close by Aug.1 and that it will make royalty payments on net sales of theproduct. Glaxo was marketing the drug in the UnitedStates.
Mount Pleasant, South Carolina-based Pernix's shares were up40 percent at $6.01. Pozen's shares were slightly lower at$8.68. (Reporting by Natalie Grover in Bangalore; Editing by SavioD'Souza)
Glaxosmithkline (GSK)