Clinical Study of B001 Injection in Subjects With Neuromyelitis Optic Spectrum Disorder (NMOSD)

Inclusion Criteria: 1. NMOSD as defined by either of the following 2015 criteria with anti-AQP4 antibody (Ab) seropositive status at screening 2. Clinical evidence of at least 1 documented relapse in last 12 months prior to screening 3. Expanded Disability Status Scale (EDSS) score from 0 to 7.5 inclusive at screening 4. Age 18 to 70 years, inclusive at the time of informed consent Exclusion Criteria: 1. Any previous treatment with anti-CD20, eculizumab, anti-BLyS monoclonal antibody (e.g., belimumab), any other treatment for prevention of multiple sclerosis (MS) relapse (e.g., interferon, natalizumab, glatiramer acetate, fingolimod, teriflunomide or dimethyl fumarate) within 6 months prior to baseline. 2. Received immunosuppression such as azathioprine, mycophenolate mofetil, methotrexate, cyclophosphamide, tacrolimus, mitoxantrone, cyclosporine A, etc, and rug therapy, biological agents such as satralizumab, tocilizumab, eculizumab, etc, 3 months prior to the first administration. 3. Evidence of serious uncontrolled concomitant diseases that may preclude participant participation, as described; Other nervous system disease, cardiovascular disease, hematologic/hematopoiesis disease, respiratory disease, muscular disease, endocrine disease, renal/urologic disease, digestive system disease, congenital or acquired severe immunodeficiency. 4. Known active infection within 3 months prior to baseline 5. Pregnancy or lactation. 6. History of severe allergic reaction to a biologic agent 7. Evidence of chronic active hepatitis B or C 8. Evidence of active tuberculosis 9. Following laboratory abnormalities at screening\*: 1. White blood cells (WBC) \<4.0 x10\^3/microliter (μL) 2. Absolute neutrophil count (ANC) 3. Absolute lymphocyte count \<0.5 x10\^3/μL 4. Platelet count \<80 x 10\^9/ L 5. Aspartate aminotransferase (AST) or alanine aminotransferase 10. History of drug or alcohol abuse within 6 months prior to baseline 11. Receipt of any live or live attenuated vaccine within 4 weeks prior to baseline 12. Uncontrolled systemic diseases, including hypertension that cannot be effectively controlled after treatment (systolic blood pressure ≥150 mmHg and/or diastolic blood pressure ≥100 mmHg), diabetes, gastrointestinal diseases, etc.; or the investigator believes that there is anything inappropriate reasons for selection.