Impax responds to recinded FDA acceptance of Impax's generic Opana ER

HAYWARD, Calif. Impax Laboratories has responded to the Food and Drug Administration following the agency’s acceptance withdrawal for the company’s drug application for a generic version of Opana ER. Opana ER is a narcotic painkiller whose generic name is oxymorphone hydrochloride.

The FDA originally accepted Impax’s application for filing but subsequently rescinded that acceptance. Impax said it believes it has submitted the information the agency needs to reaccept the application.

The company said its original application met all requirements for acceptance and that the agency’s withdrawal was “inappropriate.” It wants the FDA to reinstate its original application filing date.

Endo Pharmaceuticals and Penwest Pharmaceuticals sued Impax last month after receiving notice of the company’s application for Opana ER containing a Paragraph IV certification. Impax announced publicly that the FDA had rescinded acceptance of its application after sending out the Paragraph IV notice, according to the Nov. 15 complaint, filed in the U.S. District Court for the District of Delaware.

According to Wolters Kluwer Health, U.S. sales of Opana ER tablets were approximately $48.8 million in the 12 months ended Sept. 30, 2007.