Background:Neuromyelitis Optica Spectrum Disorder (NMOSD) is a chronic autoimmune disease of the central
nervous system that causes recurrent attacks of optic neuritis, myelitis, and brainstem symptoms, resulting in severe
neurological disability. Preventive treatment with immunosuppressive agents reduces relapse rate and improves long-term
prognosis. In recent years, the potential therapeutical effect of new agents have been investigated. Two of these, the antiinterleukin 6 (IL-6) agents tocilizumab and satralizumab, have been studied in active NMOSD.
Objective: To systematically review the current data regarding the efficacy and safety of anti-IL-6 agents in NMOSD.
Results: Fourteen case reports and 5 case series of intravenous tocilizumab have shown beneficial clinical and paraclinical
effects compared to commonly used therapies, and another case series of subcutaneous tocilizumab has shown it is as effective
as the IV formulation. A phase 2 comparative trial has shown tocilizumab IV to be more effective than azathioprine for relapse
prevention. A phase 3 trial ofsubcutaneoussatralizumab versus placebo, hasshown a lower risk of relapse in the sartralizumabtreated group, both as add-on therapy to stable immunosuppressant and as monotherapy. Tocilizumab also reduced pain
severity in two trials and fatigue scores in one trial, but satralizumab did not significantly improve pain and fatigue. Adverse
events with both agents were relatively mild and comparable to placebo and azathioprine.
Conclusions: The anti-Il-6 agents tocilizumab and satralizumab show promising results in active NMOSD.
Further randomized, larger-scale trials are needed to better define the role of these agents in the growing arsenal of NMOSD