Impact of Disease History on the Efficacy of Ritlecitinib in Patients With Alopecia Areata: Post Hoc Analysis of the ALLEGRO Phase 2b/3 Study

This post hoc analysis of the ALLEGRO phase 2b/3 study assessed the impact of disease and current AA episode duration on response to ritlecitinib in patients with alopecia areata (AA). Patients (N=653) aged ≥12 years with AA and ≥50% scalp hair loss who received daily ritlecitinib 30 or 50 mg (±4-week 200-mg daily loading dose) or placebo for 24 weeks were included. In a subsequent 24-week extension, ritlecitinib groups continued their maintenance doses and placebo groups switched to ritlecitinib 200/50 or 50 mg daily. Across treatment groups, baseline mean disease duration since diagnosis was 8.7-11.6 years and mean current AA episode duration was 3.2-3.6 years. Episode duration <1 year was significantly associated with increased likelihood of Severity of Alopecia Tool (SALT) score ≤20 (≤20% scalp hair loss) response at 24 weeks vs ≥1 year (odds ratio [OR], 0.49; 95% CI, 0.27-0.89). Disease duration (≥1 year vs <1 year) was not significantly associated with SALT score ≤20 response (OR, 1.35; 95% CI, 0.54-3.59). Higher proportions of patients with episode duration <1 year were SALT score ≤20 responders at Week 48 vs patients with episode duration ≥1 year. These results suggest that initiating therapy earlier in an AA episode may improve outcomes. Trial Registry:ClinicalTrials.gov NCT03732807, registered Nov 5, 2018