This study is aimed to observe the effectiveness and safety of inebilizumab in the acute phase of neuromyelitis optica spectrum disorders.

This is a a multicentric, prospective, real word study of inebilizumab in NMOSD acute attack compared with oral immunosuppressant. A total of 50 patients will be enrolled at approximately 10 centers around China.

Inclusion Criteria:

• 1. Age ≥ 18 years with anti-AQP4-IgG seropositive NMOSD as defined by 2015 NMOSD diagnostic criteria by IPND (International Panel for NMO Diagnosis); 2. In the acute phase of NMOSD (definition of acute phase: new neurological symptoms or aggravation of existing symptoms within 30 days before screening, lasting at least 24 hours without with fever); 3. Patients who plan to receive or are receiving intravenous methylprednisolone therapy; 4. Expanded disability status scale (EDSS) score ≤ 8 and ≥ 2.5 during the screening period; 5. Able and willing to give written informed consent; 6. Women of childbearing potential who agree to use adequate contraception during the study.

Exclusion Criteria:

• 1. Lactating and pregnant females; 2. Participate in other interventional studies within 30 days before screening or within 5 half-lives of the investigational agent before enrollment; 3. Combined with severe mental disorders and other conditions and unable to cooperate with follow-up; 4. History of malignancies; 5. Received plasma exchange, immunoadsorption or intravenous immunoglobulin therapy within 1 month before screening; 6. Patients with negative hepatitis B surface antibody (HBsAg) and positive hepatitis B core antibody (HBcAb), or HBsAg-positive virus carriers, or patients with active tuberculosis or positive tuberculosis screening without appropriate treatment history; 7. Other situations that researchers think are not suitable to participate in this study.

NMOSD patients with acute attacks