Efficacy and safety of tapinarof cream once daily in Japanese pediatric patients with atopic dermatitis: a 60-week phase 3 trial consisting of an 8-week, double-blind, vehicle-controlled period and a 52-week, open-label extension period

Background In Japan, tapinarof cream (an aryl hydrocarbon receptor agonist) is approved for the treatment of atopic dermatitis (AD) in patients aged ≥12 years. Methods In Japanese pediatric patients aged 2–11 years with AD, we conducted a 60-week phase 3 trial of tapinarof cream, consisting of an 8-week, double-blind, vehicle-controlled period (DB period) and a 52-week, open-label extension period (OL period). Eligible patients (N = 162) were randomized to tapinarof cream 0.5% (n = 107) or vehicle cream (n = 55) in the DB period; subsequently, all patients who entered the OL period (n = 151) received tapinarof cream 0.5%. Results At week 8 in the DB period, the proportion of patients with ≥75% improvement from baseline in Eczema Area and Severity Index (EASI) score (EASI-75 response, the primary endpoint) was significantly higher in the tapinarof group than in the vehicle group (52.59% vs. 12.60%, p < 0.0001). The proportion of patients who achieved an Investigator’s Global Assessment score of 0 (clear) or 1 (almost clear) with ≥ 2-grade improvement from baseline at week 8 (IGA treatment success, a key secondary endpoint) was 26.2% in the tapinarof group and 1.8% in the vehicle group. In the OL period, improvements in efficacy endpoints continued through week 60 with treatment. In the tapinarof group, EASI-75 response rate was 75.8% at week 32% and 80.2% at week 60, and IGA treatment success rate was 48.5% at week 32, and 56.3% at week 60. Across the DB and OL periods, no treatment-related serious adverse events (AEs) were reported, and all treatment-related AEs were mild or moderate. The most common treatment-related AEs included folliculitis and acne. Conclusion Tapinarof cream was effective and well tolerated for up to 60 weeks in the treatment of Japanese pediatric patients aged 2–11 years with AD.