A Study of MIL62 in Patients With Neuromyelitis Optica Spectrum Disorder (NMOSD)

Inclusion Criteria:

1. Patient with NMOSD as defined by 2015 NMOSD diagnostic criteria by IPND (International Panel for NMO Diagnosis) with anti-AQP4-IgG seropositive status.

2. Male or female aged 18～60 years.

3. Expanded Disability Status Scale(EDSS) score ≤6.5.

4. A documented history of at least one attack requiring rescue therapy in the lastyear or two attacks requiring rescue therapy in the last 2 years prior to screening.

5. Subjects who have had a relapse immediately prior to screening must have at least 12weeks in which their relapse symptoms are stable prior to the first administration.

Exclusion Criteria:

1. CD20+ B cell counts below the lower limit of normal (LLN). Receipt of rituximab orany B-cell depleting agent within the 6 months prior to screening, unless thesubject has B-cell counts above the LLN. CD4 T lymphocyte count <300cells/μL(CD4：CD8≤1.4).

2. Receipt of tocilizumab, eculizumab within 3 months prior to the firstadministration.

3. Receipt of any of the following prior to the first administration:Azathioprine,Mycophenolate mofetil,Tacrolimus,Cyclosporin,Methotrexate,Cyclophosphamide,and Patients discontinued more than 5 times thehalf-life of the drug before they could get into the group .

4. Receipt of IVIG, plasmapheresis or blood transfusion within 28 days prior to thefirst administration.

5. Any live or attenuated vaccine within 28 days prior to the first administration.