ABSTRACT
BACKGROUND: Alopecia areata (AA) is a CD8+ T cell mediated autoimmune disease characterized by non-scarring hair loss. Ivarmacitinib, a selective oral Janus kinase 1 (JAK1) inhibitor, may interrupt certain cytokine signaling implicated in the pathogenesis of AA. OBJECTIVE: To evaluate the efficacy and safety of ivarmacitinib in adult AA patients who have ≥25% scalp hair loss. METHODS: Eligible patients were randomized 1:1:1:1 to receive ivarmacitinib 2 mg, 4 mg, or 8 mg QD or placebo for 24 weeks. The primary endpoint was percentage change from baseline in Severity of Alopecia Tool (SALT) score at week 24. RESULTS: A total of 94 patients were randomized. At week 24, the least squares mean (LSM) difference in percentage change from baseline in SALT score for ivarmacitinib 2 mg,4 mg, 8 mg, and placebo groups were -30.51% (90% confidence interval [CI]: -45.25, -15.76), -56.11% (90% CI: -70.28, -41.95), -51.01% (90% CI: -65.20, -36.82) and -19.87% (90% CI: -33.99, -5.75), respectively. Two SAEs, follicular lymphoma, and COVID-19 pneumonia were reported. LIMITATIONS: Small sample size limits the generalizability of the results. CONCLUSION: Treatment with ivarmacitinib 4 mg and 8 mg doses in moderate and severe AA patients for 24 weeks was efficacious and generally tolerated.