MORRISTOWN, N.J. Watson Pharmaceuticals has filed a regulatory approval application for a generic version of a painkiller made by Endo Pharmaceuticals, prompting a patent litigation lawsuit from Endo and partner Penwest Pharmaceuticals, Watson announced Monday.
Watson is hoping to get a nod from the Food and Drug Administration for its oxymorphone hydrochloride extended-release tablets in the 40-mg strength, a generic version of Endo’s Opana.
The drug is used to treat moderate to severe pain in patients who require continuous, around-the-clock opioid treatment for extended periods of time. Opana had sales of around $245 million in 2009, according to IMS Health.
Under the Hatch-Waxman Act of 1984, the lawsuit prevents the FDA from approving Watson’s application for 30 months or until Watson wins the case or the companies reach a settlement.