A Phase 1, Randomized, Double-blind, Placebo-controlled, Crossover Study to Evaluate the Pharmacodynamic Effects of VX-150, a highly selective NaV1.8 inhibitor, in Healthy Male Adults

Objective To evaluate the analgesic potential, safety, tolerability and pharmacokinetics of VX-150, a pro-drug of a highly selective NaV1.8 inhibitor, in healthy subjects. Design This was a randomized, double-blind, placebo-controlled, crossover study in healthy subjects. Subjects Twenty healthy male subjects with an age of 18-55, inclusive, were enrolled. Eligibility was based on general fitness, absence of current or previous medical conditions that could compromise subject safety and a training assessment of pain tolerance across pain tests, to exclude highly tolerant individuals that could compromise the ability to detect analgesic responses. All dosed subjects completed the study. Methods Subjects were randomized 1:1 to 1 of 2 sequences receiving a single VX-150 dose and subsequently placebo, or vice versa, with at least 7 days between dosing. A battery of pain tests (pressure, electrical stair, (capsaicin-induced) heat and cold pressor) was administered pre-dose and repetitively up to 10 h post-dose, with blood sampling up to 24 h post-dose. Safety was monitored throughout the study. Data were analyzed with a repeated measures mixed-effects model. Results VX-150 induced analgesia in a variety of evoked pain tests, without affecting subject safety. Significant effects were reported for cold pressor and heat pain thresholds. Maximum median concentration for the active moiety was 4.30 ug/mL at 4 h post-dose. Conclusion Results of this proof-of-mechanism study are supportive of the potential of VX-150, a highly selective NaV1.8 channel inhibitor, to treat various pain indications.