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 Combined with or without systemic lupus erythematosus(SLE) 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 Tumor disease currently or within last 5 years Pregnant, breastfeeding, or child-bearing potential during the course of the study Clinically relevant heart, liver, kidney or bone marrow function disorder