MODERN BIOLOGICAL TREATMENT METHODS FOR ALOPECIA AREATA: A COMPREHENSIVE REVIEW

Introduction: Alopecia areata (AA) is a chronic, immune-mediated hair-loss disorder driven by cytotoxic T-cell activation and loss of hair-follicle immune privilege. Janus kinase (JAK) inhibitors and emerging targeted biologics have reshaped treatment options for moderate-to-severe AA. This review compared three approved JAK-based therapies (ritlecitinib, baricitinib, deuruxolitinib) and summarized evidence on investigational biologic agents. Materials and Methods: This narrative review was based on a structured search of PubMed and Google Scholar for English-language publications available up to 2025. Search terms included “alopecia areata,” “biologic therapy,” “JAK inhibitors,” “ritlecitinib,” “baricitinib,” “deuruxolitinib,” and “immunomodulation.” Phase 2 and 3 trials, early-phase studies, observational research, and review articles were screened. Full texts were assessed to extract information on mechanisms of action, JAK-isoform selectivity, clinical efficacy measured by SALT outcomes, safety, and emerging therapeutic strategies. Results: All three JAK inhibitors showed significant efficacy compared with placebo but differed in selectivity and response dynamics. Ritlecitinib (JAK3/TEC) demonstrated a rapid onset of action and a favorable safety profile. Baricitinib (JAK1/2) produced gradual, sustained improvement supported by extensive long-term data. Deuruxolitinib (JAK1/2/TYK2) achieved high SALT ≤20 response rates across THRIVE-AA trials. Emerging biologics such as bempikibart (anti–IL-7Rα) and early investigational agents (ALD-102, DR-01) showed preliminary efficacy, though evidence remains limited by short follow-up and lack of predictive biomarkers. Conclusions: JAK inhibitors constitute a major therapeutic advance for moderate-to-severe AA, providing meaningful clinical benefit with acceptable safety. Novel biologic agents may offer more selective and durable immune modulation. Long-term studies and development of precision-medicine approaches will be essential to optimize future AA management.