Risankizumab in Patients with Moderate-to-Severe Atopic Dermatitis: A Phase 2, Randomized, Double-Blind, Placebo-Controlled Study

Introduction: Atopic dermatitis (AD) is a heterogeneous disease, with involvement of the T-helper cell (Th) 2, Th22, and potentially Th17 pathways, supporting the use of interleukin (IL)-23 and IL-22 blockade in AD.Methods: This phase 2, multicenter, randomized, double-blind, placebo-controlled trial (NCT03706040) evaluated the efficacy and safety of risankizumab, an IL-23 inhibitor, in patients (> 12 years old) with moderate-to-severe AD, defined by an Eczema Area and Severity Index (EASI) >= 16, affected body surface area >= 10%, and a Validated Investigator Global Assessment for AD (vIGA-AD) score >= 3. Patients were randomized 2:2:1 to 16-week treatment with risankizumab 150 mg, risanki-zumab 300 mg, or placebo in period A; patients receiving placebo were re-randomized 1:1 to risankizumab 150 mg or 300 mg and patients receiving risankizumab continued on their randomized dose in 36-week period B. Study drug was administered at baseline and weeks 4, 16, 28, and 40. The primary endpoint was the proportion of patients achieving a >= 75% reduction from baseline in EASI (EASI 75) at week 16. Safety was analyzed in all randomized patients who received study medication.Results: Neither the risankizumab 150 mg (n = 69) nor the 300 mg dose group (n = 69) demonstrated a significantly higher proportion of patients achieving EASI 75 at week 16 com-pared with the placebo group (n = 34; treatment difference [95% CI] 13.0% [-1.7 to 27.7%; P = 0.084] and 10.0% [-4.6 to 24.6%; P = 0.179], respectively). Most adverse events were mild to moderate in severity; five patients receiving risankizumab reported serious adverse events, including two patients who reported cellulitis.Conclusions: Risankizumab was generally well tolerated, with no new safety concerns identi-fied. The study's primary endpoint was not met, with no significant difference in the proportion of patients achieving an EASI 75 response at week 16 with risankizumab 150 mg or 300 mg versus placebo.