Pfizer’s ALO-02 meets efficacy endpoint in Ph III

US pharma behemoth Pfizer (NYSE: PFE) has released top-line results from a Phase III study of ALO-02 (oxycodone HCl and naltrexone HCl extended-release capsules) showing that the investigational agent met the primary efficacy endpoint, demonstrating a statistically significant difference from placebo.

This was a 12-week, double-blind, placebo-controlled, randomized withdrawal design efficacy and safety study in patients with moderate-to-severe chronic low back pain. Patients who achieved a stable and effective dose of ALO-02 (10-80mg twice per day) during the four-to-six week, open-label titration period were randomized (n=281) to the 12-week, double-blind period in which they were either maintained on their current dose regimen of ALO-02 (n=147) or were tapered to placebo (n=134).

The primary efficacy endpoint of the study was defined as the difference between ALO-02 and placebo in the mean change in the daily average pain numerical rating scale (NRS-Pain) scores from baseline (just prior to randomization) to the final two weeks of the double-blind treatment period. Pain was self-reported daily on an 11-point numeric rating scale (daily NRS; 0=no pain, 10=worst possible pain). Mean changes in the primary endpoint, NRS-Pain scores from baseline to the final 2 weeks, were significantly different between ALO-02 and placebo.