Long-term, Open-label, Safety Study of Inebilizumab in Neuromyelitis Optica Spectrum Disorder (NMOSD)

Eligibility Criteria

• 1. Age 18 years or above, and able to provide written informed consent and any locally required authorization (e.g., Health Insurance Portability and Accountability Act \[HIPAA\] in the United States of America (USA), European Union \[EU\] Data Privacy Directive in the EU) obtained from the subject/legal representative prior to performing any protocol-related procedures, including screening evaluations.
• 2. Have completed at least 2 years in the open-label period of the N-MOmentum study or are newly initiating inebilizumab treatment at a participating site.
• 3. Females of childbearing potential who are sexually active with a nonsterilized male partner must use a highly effective method of contraception as outlined in the protocol (subjects in the Czech Republic only must use 1 additional method of contraception) from screening, and must agree to continue using such precautions for 6 months after treatment with inebilizumab; cessation of contraception after this point should be discussed with a responsible physician.
• 4. Nonsterilized males who are sexually active with a female partner of childbearing potential must use a male condom plus spermicide (subjects in the Czech Republic only must use 1 additional method of contraception) from Day 1 for 3 months after receipt of last treatment with inebilizumab.
• 5. Sterilized males, without the appropriate post-vasectomy documentation on the absence of sperm in the ejaculate, who are sexually active with a female partner of childbearing potential must use a condom and spermicide from Day 1 for 3 months after receipt of the last treatment with inebilizumab.
• 1. Have any condition that would place the participant at unacceptable risk of complications, interfere with evaluation of inebilizumab or confound the interpretation of participant safety or study results.
• 2. Received rituximab or any other B-cell depleting agent after exit from N-MOmentum study, or within the last 12 months prior to screening for non N-MOmentum participants.
• 3. Known history of allergy or reaction to any component of inebilizumab formulation or history of anaphylaxis following any biologic therapy
• 4. Have a severe clinically significant infection, including active chronic infection such as hepatitis B
• 5. Have active or untreated latent tuberculosis
• 6. Have a history of progressive multifocal leukoencephalopathy (PML)
• 7. Is severely immunocompromised state
• 8. Have active malignancies