Alopecia areata is an autoimmune condition characterized by rapid hair loss in the scalp, eyebrows, and eyelashes, for which treatments are limited. Baricitinib, an oral, selective, reversible inhibitor of Janus kinases 1 and 2, may interrupt cytokine signaling implicated in the pathogenesis of alopecia areata.

Background The oral Janus kinase (JAK) inhibitor baricitinib has demonstrated efficacy for severe alopecia areata (AA) over 36 weeks. There are limited data on the longer-term treatment of AA. Objective The aim of this study was to evaluate the efficacy and safety of baricitinib for AA in adults with ≥50% scalp hair loss through 52 weeks of continuous therapy in two phase III trials (BRAVE-AA1 and BRAVE-AA2). Methods Patients randomized to baricitinib at baseline in BRAVE-AA1 (N = 465) and BRAVE-AA2 (N = 390) retained their treatment allocation through Week 52. Efficacy outcomes included the proportion of patients achieving a Severity of Alopecia Tool (SALT) score ≤ 20 (≤ 20% scalp hair loss). Data were censored after permanent treatment discontinuation or if collected remotely due to the coronavirus disease 2019 (COVID-19) pandemic. Results Response rates for hair regrowth increased over the 52-week period. Of patients treated with baricitinib 4 mg and 2 mg, respectively, 40.9% and 21.2% in BRAVE-AA1 and 36.8% and 24.4% in BRAVE-AA2 achieved a SALT score ≤ 20 at Week 52. The most frequent treatment-emergent adverse events included upper respiratory tract infection, headache, nasopharyngitis, acne, urinary tract infection, creatine phosphokinase elevation, and COVID-19 infection. Limitation There were no comparisons with placebo. Conclusion Efficacy of baricitinib for adults with severe AA continuously improved over 52 weeks, indicating that long-term treatment may be necessary to observe maximum clinical benefit. There were no new safety signals. ClinicalTrials Registration ClinicalTrials.gov NCT03570749 and NCT03899259. Video abstract Efficacy and Safety of Baricitinib in Patients with Severe Alopecia Areata: Week-52 Results from BRAVE-AA1 and BRAVE-AA2