Shares of

Endo Pharmaceuticals

(ENDP) - Get Report

were down 26% after the company said a trial of its pain relief product didn't meet expectations.

Recently, shares were down $2.54 to $6.96 on the



The company said its product, MorphiDex, failed to provide superior pain relief when compared with regular doses of morphine alone in a Phase III study. "No statistically significant difference in analgesia was observed in the MorphiDex group compared to the morphine sulfate alone group," the company said in a press release.

"The company believes that the data that has been generated to date would suggest that we will not have enough evidence to support the filing of an amendment to the MorphiDex NDA," said Carol A. Ammon, chief executive of Endo.

The trial was given to patients with moderate-to-severe chronic pain and was the second of three trials.

Chadds Ford, Pa.-based Endo is a pharmaceutical company specializing in pain management products.