Endo Pharmaceuticals Inc, a wholly owned subsidiary of Endo Pharmaceuticals Holdings Inc, submitted to the U.S. Food and Drug Administration a New Drug Application (NDA) for oxymorphone extended release tablets (oxymorphone ER). Endo is developing oxymorphone ER, an oral extended release opioid analgesic, with Penwest Pharmaceuticals Co for the treatment of moderate-to-severe pain in patients requiring continuous, around-the-clock opioid therapy for an extended period of time.

"This filing represents the achievement of a major milestone for Endo," said Carol A. Ammon, chairman and chief executive officer. "It reflects our success in building the capability to develop proprietary, patent-protected drugs." She noted that, if approved, oxymorphone ER would give physicians and their patients an important new option for managing chronic pain with twice- daily dosing, and would compete in the growing, approximately $2 billion market for long-acting oral opioids.

The filing is based on a development program involving more than 2,400 patients.