By Christopher Norton

Law360, Washington (May 13, 2011, 8:23 PM ET) -- The Federal Circuit on Friday revived a nixed Endo Pharmaceuticals Inc. drug patent application related to a formulation of the painkiller Opana, but affirmed the U.S. Patent and Trademark Office's rejection of two other related patents.

Endo is the assignee of three patent applications related to controlled-release tablets containing the opioid narcotic oxymorphone, U.S. Patent Numbers 11/680,432; 12/167,859; and 11/766,740. The Board of Patent Appeals and Interferences, in separate appeals, affirmed the rejection of the claims of each application as obvious, and Endo appealed each decision...