Efficacy and Safety of Mitoxantrone in Patients With Refractory Neuromyelitis Optica and Spectrum Disorders

Inclusion Criteria: * Recurrent longitudinal myelitis (\>3 segments of spinal cord involvement by MRI) with or without recurrent ON (unilateral or bilateral) but with normal brain MRI and positive serological NMO IgG antibody. * Recurrent longitudinal myelitis (\>3 segments of spinal cord involvement by MRI) with or without spatially limited brain lesion and positive serological NMO IgG antibody. * NMO, fulfilled Wingerchuk 2006 Criteria for NMO. * Patient presented at least 2 relapses during the 12 months preceding the start of mitoxantrone therapy, despite immunotherapies using corticosteroid, interferon beta, azathioprine, cyclophosphamide, Cyclosporin A, Mycophenolate Mofetil or a combination of these drugs * Extended Disability Status Score 3-8. * Normal range for white-blood-cell count (more than 4×109/L), neutrophil count (more than 2×109/L), and platelet count (more than 100×109/L). Exclusion Criteria: * Cardiac risk factors (e.g history of congestive heart failure and left ventricular ejection fraction (LVEF) \< 50% * Systemic diseases such as lupus, Sjogren's syndrome, anti-phospholipid antibody syndrome, sarcoidosis, rheumatoid arthritis, or vitamin B12 deficiency * Previous treatment with mitoxantrone or anthracyclines * Pregnant or planning to be pregnant * Patients with severe liver disorders (WHO grade 4)