Endo Pharmaceuticals Holdings Inc., a market leader in pain management, announced that the U.S. Food and Drug Administration (FDA) has granted final approval of Endo's abbreviated new drug application (ANDA) for oxycodone extended-release tablets, 10mg, 20mg and 40mg. Endo's oxycodone extended-release tablets are AB-rated bioequivalent versions of the 10mg, 20mg and 40mg strengths of OxyContin, a product of The Purdue Frederick Company that is indicated for the management of moderate-to-severe pain when a continuous, around-the-clock analgesic is needed for an extended period of time. OxyContin had combined 2003 U.S. branded sales of approximately $1.9 billion. The 10mg, 20mg and 40mg strengths represent approximately 63 per cent of the US branded sales of OxyContin.

On January 5, 2004, the U.S. District Court for the Southern District of New York issued an Opinion and Order dismissing the claims that Endo's oxycodone extended-release tablets, 10mg, 20mg, 40mg, and 80mg, infringe Purdue's U.S. Patent Nos. 5,549,912, 5,508,042 and 5,656,295, declaring the patents invalid, and enjoining Purdue from enforcing the patents. On January 12, 2004, Purdue filed a Notice of Appeal in the United States District Court for the Southern District of New York, petitioning the United States Court of Appeals for the Federal Circuit to overturn the District Court's January 5, 2004 ruling. Purdue requested that the District Court stay its injunction against enforcement of the patents until its appeal was resolved, but such request was denied by the District Court on February 13, 2004. Purdue had also petitioned the Federal Circuit to stay the District Court's injunction during the pendency of its appeal and to expedite the appeal. The Federal Circuit denied both requests on March 19, 2004, noting that "we are not persuaded that Purdue has shown a strong likelihood that it will succeed in establishing that the district court's findings concerning materiality and intent are clearly erroneous."

The FDA also confirmed that Endo will have 180 days of marketing exclusivity with respect to the 10mg, 20mg and 40mg strengths of this product, since the company was the first applicant to file an ANDA containing a Paragraph IV certification for these oxycodone extended-release strengths.

The FDA also reaffirmed the tentative approval to market the 80mg strength, which will be granted final approval upon the expiration of another company's exclusivity on this strength. Finally, the FDA has informed Endo that it has found Endo's Risk Management Plan adequate to support Endo's marketing of its oxycodone extended-release tablets.

Carol A. Ammon, Endo's chairman and chief executive officer, stated, "We are extremely pleased by the FDA's approval of our oxycodone extended-release product, which represents a substantial market opportunity for Endo and reinforces our leadership position in pain management. We will be making a decision with respect to the launch of our oxycodone extended-release product in due course."