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

Abstract

Background: 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. Methods: 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. Results: 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. Conclusion: Interleukin-6-receptor inhibitors therapy showed a promising result with good efficacy and acceptable adverse events profile for treatment of NMOSD.