Efficacy and Safety of Ruxolitinib in Neuromyelitis Optica Spectrum Disorders

Inclusion Criteria: Male or female patients ≥ 18 years old; Diagnosis of NMO or NMO spectrum disorder according to the 2015 International diagnostic criteria for neuromyelitis optic; Clinical evidence of at least 2 relapses in last 12 months or 3 relapses in the last 24 months; EDSS \<= 6.0; Rituximab should be used for at least 3 months if the condition is stable; Able and willing to give written informed consent and comply with the requirements of the study protocol. Exclusion Criteria: Current evidence or known history of clinically significant infection (Herpes simplex virus, varicella-zoster virus, cytomegalovirus, Epstein-Barr virus, human immunodeficiency virus, Hepatitis viruses, Syphilis, etc); Participation in another interventional trial within the last 3 months; Patients taking oral immunosuppressants such as azathioprine; Tumor disease currently or within last 5 years; Pregnant, breastfeeding, or child-bearing potential during the course of the study; Clinically relevant anemia, thrombocytopenia and dysfunction of the heart, liver, kidney or bone marrow.