Neuromyelitis optica spectrum disorders: Emerging therapies

Abstract

AbstractNeuromyelitis optica or neuromyelitis optica spectrum disorders (NMOSD) are autoimmune diseases associated with a disease‐specific autoantibody directed against the water channel protein aquaporin‐4. While almost all patients with NMOSD show a relapsing‐remitting course, just 2% of patients present with a progressive course, suggesting that preventing acute attacks can lead to stable remission and avoid progression of the condition. Standard immunotherapy, immunosuppressive agents, and corticosteroids can prevent acute attacks and maintain remission in the majority of patients with NMOSD. However, there is a strong need for alternative options for patients who are refractory to standard treatments. Emerging therapies targeting specific molecules related to the pathogenicity of NMOSD are currently being developed. In addition to standard intravenous high‐dose corticosteroid and plasma exchange/plasmapheresis, therapies targeted at inhibiting granulocytes, complement, and vascular endothelial growth factor are anticipated for acute attacks. With regard to preventive treatment of NMOSD, randomized clinical trials using monoclonal immunoglobulin G antibody targeting CD19 and CD20 on B cells, interleukin‐6, and complement protein C5 are underway. There are many preclinical therapeutic agents that target aquaporin‐4 and the pathogenic anti‐aquaporin‐4 antibody itself: complement inhibitor and T helper 17 cells based on the specific NMOSD pathology. The future goal of immunotherapies for NMOSD would be to select suitable therapies for the patient's pathological condition among off‐target and molecular‐target agents.