Serlopitant reduced pruritus in patients with prurigo nodularis in a phase 2, randomized, placebo-controlled trial.

BACKGROUND: Anecdotal evidence suggests that neurokinin 1 receptor antagonism reduces pruritus intensity in chronic pruritic conditions such as prurigo nodularis (PN). OBJECTIVE: This study assessed safety and efficacy of the neurokinin 1 receptor antagonist serlopitant for treatment of pruritus in PN. METHODS: In this randomized, double-blind, placebo-controlled study, 128 patients with chronic, treatment-refractory PN for more than 6 weeks received serlopitant, 5 mg, or placebo orally once daily for 8 weeks. The primary end point was change in average itch visual analog scale score at weeks 4 and 8. RESULTS: Average itch visual analog scale scores significantly improved with serlopitant versus with placebo at weeks 4 and 8: the least squares mean difference (serlopitant minus placebo) was -1.0 at week 4 (P = .02) and -1.7 at week 8 (P < .001). The least squares mean difference between serlopitant and placebo reached statistical significance at week 2 (-0.9 [P = .011]). The most frequently reported treatment-emergent adverse events in the serlopitant group were nasopharyngitis, diarrhea, and fatigue. LIMITATIONS: The 8-week duration may be insufficient to assess clinically relevant resolution of PN lesions. CONCLUSIONS: Serlopitant reduced pruritus in patients with treatment-refractory PN and was well tolerated.

Serlopitant for the treatment of chronic pruritus: Results of a randomized, multicenter, placebo-controlled phase 2 clinical trial.

BACKGROUND: The substance P/neurokinin 1 receptor pathway is critical in chronic pruritus; anecdotal evidence suggests that antagonism of this pathway can reduce chronic itch. OBJECTIVE: To assess the safety and efficacy of the substance P/neurokinin 1 receptor antagonist serlopitant in treating chronic pruritus. METHODS: Eligible patients with severe chronic pruritus who were refractory to antihistamines or topical steroids were randomized to serlopitant, 0.25, 1, or 5 mg, or to placebo, administered once daily for 6 weeks as monotherapy or with midpotency steroids and emollients. The primary efficacy end point was percentage change in visual analog scale pruritus score from baseline. RESULTS: Serlopitant treatment resulted in a dose-dependent decrease in pruritus. The mean percentage decreases from baseline visual analog scale pruritus scores were statistically significantly larger with the 1- and 5-mg doses of serlopitant (P = .022 and P = .013, respectively) than with placebo at week 6. No significant safety or tolerability differences were detected among the groups. LIMITATIONS: The sample size was insufficient for subgroup analyses of the efficacy of serlopitant for chronic pruritus on the basis of underlying conditions. CONCLUSIONS: Serlopitant, 1 mg and 5 mg daily, was associated with a statistically significant reduction in chronic pruritus and was well tolerated (NCT01951274).