Efficacy and Safety of Monoclonal Antibody in Acute Phase of Neuromyelitis Optica Spectrum Disorder

Prior treatment

• Received treatment with monoclonal antibody (including rituximab, satralizumab, inebilizumab, eculizumab, efgartigimod, etc.) within 3 months prior to screening.
• Received treatment with IVIg, plasma exchange (PE), IVMP, or oral corticosteroids \>30 mg/day within 1 month prior to screening.
• Patients who have independently discontinued immunotherapy or demonstrate poor adherence.
• Presence of severe underlying diseases or other conditions that may affect the safety of immunotherapy or the interpretation of study results, including but not limited to: a) Chronic or active infections requiring long-term systemic treatment (e.g., progressive multifocal leukoencephalopathy, chronic renal infection, chronic respiratory infection with bronchiectasis, active tuberculosis, active hepatitis C, etc.); b) Positive hepatitis B serology (except in individuals with prior vaccination); c) History or suspicion of tuberculosis; d) Positive HIV serology; e) History or current clinically significant adverse reactions (including severe allergic reactions) related to corticosteroids, FcRn antagonists, or complement inhibitors.

Other illness

• Any other condition deemed by the investigators to make participation in the study inappropriate.

Other

• Participation in a randomized clinical trial with blinded treatment allocation.
• Incomplete or unavailable follow-up data, expected inability to complete follow-up, or poor compliance.
• Pregnant or breastfeeding women, or women planning pregnancy in the near future (contraception required during treatment).

• Age at onset ≥18 years, any gender.
• Patients meeting the 2015 International Panel for NMO Diagnosis (IPND) criteria for NMOSD and currently in the acute phase, defined as new or significantly worsened neurological deficits lasting \>24 hours, with onset within \<14 days, excluding pseudo-relapses caused by fever, infection, or metabolic disturbances. The acute relapse must meet at least one of the following clinical phenotypes: a) Optic neuritis (ON): EDSS visual function score ≥3; b) Transverse myelitis (TM): EDSS pyramidal function score ≥2. NMOSD-related syndromes (e.g., area postrema syndrome, acute brainstem syndrome, acute diencephalic syndrome, cerebral syndrome) may be present as concomitant features but cannot be the sole or primary manifestation.
• Serum AQP4-IgG positive by cell-based assay (CBA) with a titer ≥1:32, and negative for MOG-IgG (CBA or LCBA) and GFAP-IgG.
• Expanded Disability Status Scale (EDSS) score at enrollment ≥3 and ≤8 points.
• Planned to receive or currently receiving intravenous methylprednisolone (IVMP) treatment, and not on or only using conventional immunosuppressive maintenance therapy.
• Able to comply with standardized follow-up, with an expected minimum follow-up of 12 months during the study period.
• Signed informed consent by the patient or legal guardian (if applicable).