Clinical Data A 257-patient phase 2 trial (TCP-101) evaluating serlopitant for the treatment of chronic pruritus (itch) successfully met its primary efficacy endpoint, demonstrating a statistically significant difference in pruritus change from baseline in subjects treated with 1 mg and 5 mg serlopitant compared with placebo (p<0.05 at weeks 4, 5, and 6). Additionally, a post-hoc analysis to evaluate time to onset demonstrated a statistically significant antipruritic benefit observed by day 3 of treatment with 1 mg and 5 mg of serlopitant compared with placebo (p<0.05).   

The study successfully demonstrated greater reduction of pruritus with serlopitant compared with control on the primary endpoint analysis for both the 1 mg and 5 mg dose groups (p<0.05 at weeks 4, 5, and 6). At week 6, the serlopitant 1 mg and 5 mg groups reported mean percent reduction from baseline VAS pruritus scores of 41.4% and 42.5%, respectively, as compared with 28.3% in the placebo-treated group. Statistically significant differences in change from baseline NRS pruritus scores (a secondary endpoint) were observed for both serlopitant 1 mg and 5 mg at weeks 4, 5, and 6 compared to placebo (p<0.05). Serlopitant was well tolerated in the TCP-101 study. The majority of treatment-emergent adverse events were mild to moderate in severity.