Impax Laboratories Inc said partner GlaxoSmithKline Plc ended their collaboration on Impax's experimental Parkinson's disease drug due to regulatory and launch delays in the countries in which GSK has rights to market the drug.
Impax shares fell 2 percent to $17.32 in premarket trade after closing at $17.62 on Friday on the Nasdaq.
Under a deal, GlaxoSmithKline had the right to develop and market the drug, IPX066, outside the United States and Taiwan.
Rights to the drug, which is known as Rytary in the United States, will transfer back to Impax at the end of July 2013.
Impax did not disclose the financial impact of the deal termination, if any. It said it plans to find a partner or partners for markets outside the United States.
Rytary is an extended-release capsule being developed for the symptomatic treatment of adult patients with idiopathic Parkinson's disease.
(Reporting by Esha Dey in Bangalore; Editing by Sreejiraj Eluvangal)