RecruitingDrug trialEfficacy and Safety of Baricitinib in Neuromyelitis Optica Spectrum DisordersNeuromyelitis Optica Spectrum Disorders (NMOSD) is associated with a pathological humoral immune response against the aquaporin-4(AQP-4) water channel. Baricitinib is an oral Janus kinase (JAK)1/JAK2 inhibitor that blocks the upregulated JAK-STAT pathway in patients with neuroimmune disorders, which is important in bone marrow regulation of B cell proliferation and differentiation. Baricitinib may benefit some patients with NMOSD due to the important role of B cells in the pathogenesis of NMOSD. Clinical trials may be needed to observe its efficacy and safety.