In this multicenter, randomized, double-blind, parallel group trial, the safety and efficacy of oxymorphone ER were compared with placebo in 142 opioid-experienced patients with moderate-to-severe chronic low back pain.
Oxymorphone ER demonstrated a statistically significant difference in pain scores from placebo during a 12-week treatment period, during which the drug was administered twice daily. The drug was generally well tolerated, with no single adverse event reaching an incidence of over 10% in either group.
On August 22, 2005, Endo announced the results of a Phase III trial of oxymorphone ER conducted in response to the US Food and Drug Administration’s request for additional clinical data to support Endo’s new drug application for this developmental product.
This first trial evaluated oxymorphone ER in opioid-naive patients and was conducted under the FDA’s special protocol assessment process. Apart from the patient population studied, the protocols for the two trials were virtually identical, including the primary and secondary efficacy analyses. In the earlier trial, oxymorphone ER also demonstrated a statistically significant difference in pain scores.