Evaluate the Safety and Tolerability of CE211NS21 in Patients With AQP4-IgG-positive NMOSD Relapse

Inclusion criteria

• . Male or female adults aged 19 years or older and 65 years or younger (by full age) at the time of obtaining informed consent.
• . Patients who have a bone marrow donor who is 19 years or older and 70 years or younger (by full age) among their blood relatives.
• . Patients diagnosed with anti-aquaporin-4-immunoglobulin G (AQP4-IgG) positive neuromyelitis optica spectrum disorder based on serum testing at the time of screening.
• . Patients who have experienced a severe relapse† (first attack or acute relapse) within 28 days prior to screening and meet the following criteria. However, in patients with both transverse myelitis and optic neuritis, the criteria for the site of relapse are applied.
• . Patients who can come to outpatient visits alone or with caregiver assistance
• . Women of childbearing potential who have not undergone sterilization must agree to use appropriate contraception\* until 12 months after the administration of the investigational product, and must provide evidence of not being in a childbearing state at the time of screening by meeting one of the following criteria:
• . For male patients who have not undergone a vasectomy: The patient must agree to use a barrier method of contraception (e.g., condoms) and ensure that he and his partner use appropriate contraception\* until 12 months after the administration of the investigational product, and must agree to refrain from donating sperm.
• . Patients who have been fully informed about this clinical trial, have voluntarily agreed to participate, and have given written consent to comply with the clinical trial's requirements.