Crisaborole Topical Ointment, 2% in Adults With Atopic Dermatitis: A Phase 2a, Vehicle-Controlled, Proof-of-Concept Study

Background: A novel approach for treating atopic dermatitis (AD) is the inhibition of phosphodiesterase 4 (PDE4), an enzyme involved in the proinflammatory cascade. Crisaborole topical ointment, 2% is a novel, boron-based small-molecule PDE4 inhibitor with anti-inflammatory properties. The objective of this proof-of-concept study was to assess the efficacy and safety of crisaborole topical ointment, 2% in adults with mild to moderate AD. Methods: This phase 2a, randomized, double-blind, bilateral, 6-week study of crisaborole topical ointment, 2% was conducted in adult patients with mild to moderate AD with 2 comparable target AD lesions. Patients were randomly assigned to twice-daily application of crisaborole topical ointment, 2% or vehicle, each to 1 of the 2 target lesions. The primary efficacy endpoint was change from baseline in Atopic Dermatitis Severity Index (ADSI) score at day 28. Safety assessments included local tolerability and incidence of adverse events (AEs). Results: A total of 25 enrolled patients received study medication. At day 28, 17 patients (68%) experienced a greater decrease in ADSI score in the active-treated lesion than in the vehicle-treated lesion; 5 patients (20%) had a greater decrease in ADSI score in the vehicle-treated lesion than in the active-treated lesion. Local application-site reactions were reported in 3 patients (12%). A total of 29 AEs were reported in 11 patients; most (90%) were mild in intensity and unrelated to study medication. No serious or severe AEs were reported, and no patient discontinued due to an AE. Conclusions: These findings. provide preliminary evidence of the efficacy and safety of treatment with crisaborole topical ointment, 2% in adults with mild to moderate AD. The study is registered on ClinicalTrials.gov (identifier NCT01301508).