Flexion Therapeutics, Inc. announced the expansion of the Phase 1b randomized, double-blind, placebo-controlled trial of FX301 in patients undergoing bunionectomy. FX301 is a novel formulation of a locally administered NaV1.7 inhibitor (funapide) which aims to provide at least three to five days of post-operative pain relief while preserving motor function. The company’s decision to advance FX301 into the expansion cohort follows a review of safety data from the single ascending dose stage of the trial by an independent Safety Monitoring Committee. Subsequently, an internal review committee assessed safety, systemic exposure and efficacy data and made the decision to advance the program. The single ascending dose stage of the Phase 1b trial was designed to evaluate the safety and tolerability of four dosing cohorts of 12 patients each (9 active:3 placebo). In the expansion cohort, an additional 36 patients will be randomized (1:1) to receive either FX301 at the selected dose (130 mg/low volume) or placebo to further assess the safety, tolerability, systemic exposure, and efficacy of FX301 as a single-injection analgesic nerve block adjacent to the sciatic nerve of the popliteal fossa.