A Clinical Research Study of Inebilizumab in Neuromyelitis Optica Spectrum Disorders

Inclusion Criteria:

• Patients who have comprehensive understanding of the study content, process andpossible adverse reactions, and sign the informed consent forms voluntarily
• Men and women 18 years or older
• Patients with NMOSD diagnosed according to the definition in the Guidelines for theDiagnosis and Treatment of Neuromyelitis Optica Spectrum Disorders in China
• Patients with positive serum anti-AQP4-IgG results at screening
• A documented history of one or more NMOSD acute relapses that required rescue therapywithin the last year, or 2 or more NMOSD acute relapses that required rescue therapywithin 2 years prior to screening
• Patients with EDSS score of ≤ 7.5 points
• Patients who and whose sexual partner agree to take highly effective method ofcontraception from screening

Exclusion Criteria:

• Patients who have received any of the following treatments at any time prior torandomization:

1. Monoclonal antibodies against CD52: such as alemtuzumab, etc.
2. Total lymphoid irradiation
3. Bone marrow transplant
4. T-cell vaccination therapy

• Receipt of rituximab or other B-cell depleting agents (e.g., Belimumab, Telitacicept)within 6 months prior to screening, unless the patient has B-cell counts above the LLNaccording to the central laboratory;
• Receipt of rituximab or other B-cell depleting agents (e.g., Belimumab, Telitacicept)within 6 months prior to screening, unless the patient has B-cell counts above the LLNaccording to the central laboratory;
• Patients who have received intravenous injection of immunoglobulin (IVIG) within 1month prior to randomization;
• Patients who have received immunosuppressant therapy (e.g., cyclophosphamide,methotrexate, mitoxantrone, ciclosporin A, etc.) and biologics (satralizumab,natalizumab, tocilizumab, eculizumab, etc.) within 3 months or 5 half-lives of suchdrugs (whichever is longer) before randomization;
• Any concomitant disease other than NMOSD that required treatment with oral or IVsteroids at doses > 20 mg/day for > 21 days within the 6 months prior to screening;
• Concurrent/previous enrollment in another clinical study involving an investigationaltreatment within 4 weeks or 5 published half-lives of the investigational treatment,whichever is the longer, prior to enrollment;
• Severe drug allergic history or anaphylaxis to two or more food products or medicine (including known sensitivity to acetaminophen/paracetamol, diphenhydramine orequivalent antihistamine, and methylprednisolone or equivalent glucocorticoid); Knownhistory of allergy or reaction to any component of the investigational productformulation or history of anaphylaxis following any biologic therapy;
• Patients with evidence of alcohol, drug, or chemical abuse, or with history of suchabuse within 1 year prior to randomization;
• Female patients who are lactating or pregnant, or plan to become pregnant at any timefrom signing the informed consent through the study plus 6 months following last doseof investigational product;
• Patients with clinically significant serious active or chronic viral infection, orbacterial infection within 60 days prior to randomization, which requires treatmentwith anti-infective agents or hospitalization, or might pose an additional risk to thepatient in the opinion of the investigator;
• Patients with known history or underlying disease of primary immunodeficiency (congenital or acquired), such as human immunodeficiency virus (HIV) infection orsplenectomy, which predisposes the patient to infection;
• Confirmed positive serology results of hepatitis B/C at screening
• Patients with history of malignancy, except squamous or basal cell carcinoma of skinthat has been successfully treated with documented success of curative therapy > 3months prior to randomization;
• Any other conditions that, in the opinion of the investigator, are not suitable forparticipating in the clinical study.