Long‐Term Real‐World Outcomes of Baricitinib in Severe Alopecia Areata: A 104‐Week Retrospective Analysis From a Single Institute

ABSTRACT Baricitinib, a Janus kinase inhibitor, demonstrated efficacy in achieving scalp hair regrowth in severe alopecia areata (AA). While short‐term real‐world data on its efficacy have been reported, long‐term data remain limited. This retrospective observational study spanning 104 weeks analyzed clinical trajectories of 51 severe AA patients treated with baricitinib. Among them, 36 continued treatment for 104 weeks, with 55.6% achieving a SALT score of ≤ 20 and 72.2% achieving ≥ 30% improvement from baseline in SALT score (SALT 30 ). Multivariate analysis identified female sex and disease duration < 4 years as significant predictors of response. Furthermore, patients with eyebrow or eyelash regrowth at 52 weeks had a higher likelihood of achieving long‐term scalp hair regrowth. We identified a subgroup of markedly slow responders who achieved SALT 30 between 52 and 104 weeks, many of whom had eyebrow or eyelash regrowth at 52 weeks. Baricitinib was well tolerated throughout the study period, with no serious long‐term adverse effects. Our findings supported baricitinib's long‐term efficacy and safety and suggested predictive factors for treatment responses in severe AA.