Effect of crisaborole topical ointment, 2%, on atopic dermatitis–associated pruritus: an extended analysis of 2 phase 3 clinical trials

Introduction: Pruritus is an essential feature of atopic dermatitis (AD) and is widely considered the most distressing symptom. Crisaborole ointment is a nonsteroidal phosphodiesterase 4 inhibitor for the treatment of mild to moderate AD. The efficacy of crisaborole for AD-associated pruritus was assessed in 2 phase 3 trials using the Severity of Pruritus Scale (SPS). Post hoc validation of the SPS identified that 1 SPS observation provided inadequate test-retest reliability. Therefore, extended analyses were conducted using at least 2 SPS observations for robust assessment of pruritus in the phase 3 crisaborole trials. Methods: Data were analyzed from 2 identically designed, vehicle-controlled, double-blind, phase 3 trials designed to investigate the efficacy and safety of crisaborole in AD patients aged 2 years and above (AD-301: NCT02118766; AD-302: NCT02118792). At least 2 SPS observations were averaged for acceptable test-retest reliability. Results: At least 2 baseline observations were available for 569 patients in AD-301 and 561 patients in AD-302. Median time to pruritus improvement (SPS score ⩽1 with at least 1-point improvement from baseline) was shorter with crisaborole than with vehicle (AD-301: 5.0 vs. 10.0 d, P=0.0003; AD-302: 6.0 vs. 9.0 d, P=0.0087). At week 4, more crisaborole-treated patients than vehicle-treated patients experienced pruritus improvement (AD-301: 37% vs. 21%, P<0.0001; AD-302: 34% vs. 21%, P=0.0006), mean pruritus scores were lower with crisaborole than with vehicle (AD-301: 0.97 vs. 1.28, P<0.0001; AD-302: 1.08 vs. 1.35, P<0.0001), and more crisaborole-treated patients than vehicle-treated patients experienced a clinically important pruritus response (AD-301: 75% vs. 57%, P<0.0001; AD-302: 72% vs. 64%, P=0.0828). Conclusions: These extended analyses show that patients treated with crisaborole experienced rapid and clinically relevant improvement in AD-associated pruritus.