Tocilizumab for severe COVID-19: a systematic review and meta-analysis

•Systemic review and meta-analysis assessing the efficacy of tocilizumab for treatment of severe COVID-19.•All-cause mortality was similar between tocilizumab and control groups (16.3% vs. 24.1%; RR = 0.62).•Risk of ICU admission was similar between tocilizumab and control groups (35.0% vs. 15.8%; RR = 1.51).•Requirement for mechanical ventilation was similar between tocilizumab and control groups (32.4% vs. 28.6%; RR = 0.82).•There is no conclusive evidence that tocilizumab provides any additional benefit to patients with severe COVID-19. This systemic review and meta-analysis aimed to assess the efficacy of tocilizumab for the treatment of severe coronavirus disease 2019 (COVID-19). Candidate studies up to 24 May 2020 were identified from PubMed, Cochrane Library, Embase, medRxiv and bioRxiv. Treatment outcomes included mortality, risk of intensive care unit (ICU) admission and the requirement for mechanical ventilation (MV). Seven retrospective studies involving 592 adult patients with severe COVID-19, including 240 in the tocilizumab group and 352 in the control group, were enrolled. All-cause mortality of severe COVID-19 patients among the tocilizumab group was 16.3% (39/240), which was lower than that in the control group (24.1%; 85/352). However, the difference did not reach statistical significance [risk ratio (RR) = 0.62, 95% confidence interval (CI) 0.31–1.22; I2 = 68%]. Additionally, risk of ICU admission was similar between the tocilizumab and control groups (35.1% vs. 15.8%; RR = 1.51, 95% CI 0.33–6.78; I2 = 86%). The requirement for MV was similar between the tocilizumab and control groups (32.4% vs. 28.6%; RR = 0.82, 95% CI 0.14–4.94; I2 = 91%). However, these non-significant differences between the tocilizumab and control groups may have been the result of baseline characteristics of the tocilizumab group, which were more severe than those of the control group. Based on low-quality evidence, there is no conclusive evidence that tocilizumab would provide any additional benefit to patients with severe COVID-19. Therefore, further recommendation of tocilizumab for COVID-19 cases should be halted until high-quality evidence from randomised controlled trials is available.