Endo Pharma and Grunenthal Ends partnership on axomadol

Endo Pharmaceuticals Holdings Inc. announced the termination of its collaboration with German drugmaker on an investigational back pain drug, axomadol.

On Jun. 30, Endo declared that axomadol had failed to achieve its primary endpoint in a clinical trial investigating its efficacy to treat moderate to severe chronic low back pain. In Feb. 2009, Endo had licensed axomadol from Grunenthal. Although Endo concealed the financial terms and conditions of the agreement, it reserved the rights to develop and sell the drug in the U.S. and Canada.

In Monday trading, Endo shares fell 59 cents to close at $31.81 and leaped up 59 cents to $32.40 in aftermarket trading.