Efficacy and Safety of Ritlecitinib in Severe Alopecia Areata: A Systematic Review

Severe alopecia areata (AA), including alopecia totalis and alopecia universalis, is a devastating autoimmune condition that causes widespread hair loss.Ritlecitinib, a selective Janus kinase 3 (JAK3) and TEC family kinase inhibitor, is emerging as a systemic therapy for severe AA.This systematic review looked at the efficacy and safety of ritlecitinib in people with severe AA.We systematically searched PubMed/MEDLINE (Medical Literature Analysis and Retrieval System Online), Embase, Scopus, and the Cochrane Library from the databases' inception through August 31, 2026.Eligible studies assessed ritlecitinib in adolescents or adults with severe AA, typically defined by a baseline Severity of Alopecia Tool (SALT) score of ≥50.Study selection and data extraction were done manually with standardized Google Sheets (Google LLC, Mountain View, California, United States), while Rayyan (Rayyan, Cambridge, Massachusetts, United States) and Zotero (Corporation for Digital Scholarship, Vienna, Virginia, United States) were utilized for screening and reference management.The risk of bias was assessed using RoB 2 (Cochrane Collaboration, London, United Kingdom) for randomized trials, ROBINS-I (Risk Of Bias In Non-randomized Studies -of Interventions) (Cochrane Collaboration) for non-randomized intervention studies, and the Newcastle-Ottawa Scale (Ottawa Hospital Research Institute, Ottawa, Canada) for observational cohorts.Because of significant clinical and methodological variation, findings were presented narratively.Five studies, totaling 483 patients, were included.High-stringency responses were seen.The mean SALT score declined consistently across investigations.Eyebrow and eyelash enhancements were also recorded.Adverse-event rates ranged from 44.4% to 67% in 24-week studies and reached 97.4% during three-year follow-up; serious adverse events occurred in 6.8% during long-term treatment.In clinical and real-world tests, ritlecitinib showed persistent scalp hair regeneration and improvement in brow and eyelash involvement, with generally controllable adverse effects.Long-term safety and efficacy studies suggest long-term clinical benefit, although interpretation was hampered by variability and the prevalence of non-randomized evidence.