A meta-analysis to determine the efficacy and safety of tocilizumab in neuromyelitis optica spectrum disorders

Abstract

BackgroundNeuromyelitis optica spectrum disorder (NMOSD) is a central nervous system immune disease with a high recurrence rate and high disability rate. Frequent relapses often cause the accumulation of neurological dysfunction, leading to permanent blindness, paralysis or even death. Tocilizumab (TCZ) is a human monoclonal antibody (mAb) directed against the IL-6 receptor and was the first anti-IL6-R mAb tested for the treatment of NMOSD. Our meta-analysis aimed to evaluate the efficacy and safety of tocilizumab in NMOSD patients. MethodsRelevant studies published prior to May 2020 were retrieved from the PubMed, Cochrane Library and clinicaltrials.gov databases using the following keywords: ‘neuromyelitis optic spectrum disorders’ or ‘NMOSD’ and ‘tocilizumab’ or ‘TCZ’. Two authors independently selected the articles and extracted the data. Differences in the annualized relapse rate (ARR) ratio, relapse-free status and EDSS score before and after TCZ therapy were used as the main efficacy measures, and recorded adverse effects were also extracted. The meta-analysis was performed using Review Manager version 5.3 software. ResultsFive clinical trials comprising a total of 89 patients were selected. Meta-analysis showed that significantly fewer ARR ratio was encountered in after tocilizumab therapy group (MD=-2.25; 95% CI=-2.62 to -1.87; P<0.001). A significant correlation was observed between the proportion of patients with relapse-free NMOSD and tocilizumab therapy (OR=67.78; 95% CI=19.23 to 238.97; P<0.001). Adverse effects were recorded in 75 of 89 (84%) patients treated with tocilizumab, but most adverse effects were mild. ConclusionsThe present meta-analysis suggested that tocilizumab is a relatively effective and safe treatment for NMOSD.