Safety and efficacy of interleukin-6-receptor inhibitors in the treatment of neuromyelitis optica spectrum disorders: a meta-analysis

Interleukin-6-receptor inhibitors like Tocilizumab and Satralizumab are showing promising results in the treatment of Neuromyelitis Optica spectrum disorder (NMOSD). We aimed to investigate the efficacy and safety of various Interleukin-6-receptor inhibitors in the management of NMO/NMOSD.PubMed, Embase, and The Cochrane Library were systematically searched for suitable studies. Change in Annualized Relapse Ratio (ARR), Change in Extended Disability Status Scale (EDSS) s, the proportion of relapse-free patients and proportion of patients with adverse events, including serious adverse events and mortality were the parameters considered for the meta-analysis for Tocilizumab. Mean difference (MD) with 95% CI was used to quantify the change in ARR and change in EDSS before and after treatment. A forest plot was prepared to indicate the efficacy and adverse effects outcomes. The results were compared with those of Satralizumab included in two trials.A total of nine studies with 202 patients were included in our study. Tocilizumab found a good proportion (76.95% CI: 0.61-0.91; p < 0.001) of relapse free patients at follow up. It also significantly reduced mean ARR (mean difference: -2.6, 95% CI: - 2.71 to - 1.68; p < 0.001) and but did not show significant difference in change in EDSS score (mean difference = - 0.79, 95% CI: - 1.89 to - 0.31; p = 0.16). Also, the toxicity profile of Tocilizumab was acceptable considering the proportions of patients with adverse events 56% (95% C.I.;0.27-0.85, I2 = 88.95%, p < 0.001), proportions of patients with serious adverse events 11% (95% C.I.; 0.05 to 0.17, I2 = 0%, p < 0.001) and zero treatment related deaths. SAkura studies for Satralizumab showed similar relapse free patients (70% to 80%) and reduction of ARR and EDSS from baseline. Some studies of Tocilizumab have shown to reduce pain and fatigue while trials of Satralizumab had non-significant findings.Interleukin-6-receptor inhibitors therapy showed a promising result with good efficacy and acceptable adverse events profile for treatment of NMOSD.