Aptinyx Inc. announced results from a Phase 2b clinical study evaluating the effects of NYX-2925 in patients with fibromyalgia. NYX-2925 did not achieve statistically significant separation from placebo on the study's primary endpoint, which assessed the change from baseline in average daily pain on the numeric rating scale (NRS) during week 12. The Phase 2b fibromyalgia study was a randomized, double-blind, placebo-controlled study designed to evaluate the efficacy and safety of NYX-2925 in approximately 300 patients with fibromyalgia.

Following a screening period, eligible patients were randomized to receive oral doses of NYX-2925 50 mg, NYX-2925 100 mg, or placebo once daily over the treatment period. The primary endpoint in the study was the change from baseline in average daily pain as reported on the zero-to-ten NRS during week 12 of the study. Statistically significant separation from placebo was not observed on the primary endpoint of the study with either dose level of NYX-2925.

Patients receiving NYX-2925 at both dose levels showed a trend toward clinically meaningful improvement in pain, as well as in some secondary endpoints, versus placebo by week 4. However, by week 12, the placebo group had improved such that, although NYX-2925 remained numerically better, the separation was not clinically meaningful. Across both dose levels, NYX-2925 was well tolerated in the study, with no concerning safety issues observed. Detailed data from the study continue to be evaluated.