Recent advances in the treatment of neuromyelitis optica spectrum disorders.

PURPOSE OF REVIEW: This review examines recently published randomized placebo-controlled trials for the treatment of neuromyelitis optica spectrum disorders (NMOSD). RECENT FINDINGS: Until recently, treatments for NMOSD were used-off label and had not been subjected to randomized placebo-controlled trials. Increased understanding of the pathophysiology of NMOSD, particularly aquaporin-4-IgG seropositive NMOSD, lead to the investigation of eculizumab, inebilizumab, and satralizumab for maintenance therapy. Eculizumab inhibits the cleavage of the terminal complement protein C5, inebilizumab depletes immune cells of B-lymphocyte lineage, and satralizumab inhibits interleukin-6 receptors. International, phase 3, randomized, placebo-controlled trials have demonstrated that each of these therapies reduces the risk of NMOSD relapse. In some cases, the studied therapies were administered in conjunction with other immunosuppressants. Each therapy has important safety considerations, notably risk of meningococcal infection with eculizumab and risks of infection and hypogammaglobulinemia with inebilizumab. Reviewing trial design highlights future areas of inquiry for the treatment of NMOSD. SUMMARY: Eculizumab, inebilizumab, and satralizumab are effective maintenance therapies approved for the treatment of AQP-4 seropositive NMOSD.