Mortality in tocilizumab-treated patients with COVID-19: a systematic review and meta-analysis.

OBJECTIVES: People who are exposed to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) could develop a potentially fatal disease with lung involvement and severe cytokine storm syndrome (CSS) - coronavirus disease 2019 (hereafter, COVID-19). Tocilizumab (TCZ) was administered to these subjects, despite the lack of randomised clinical trial data. Hence, summarising data on the mortality rate and related risks factors may help physicians to correctly administer TCZ. METHODS: We performed a systematic review and meta-analysis on mortality rate in TCZ- treated patients with COVID-19 according to the PRISMA guidelines. The pooled mortality rate in TCZ-treated persons was calculated and meta-regressions were done to investigate associated factors. RESULTS: We included 22 studies and 1520 TCZ-treated patients (mean age: 61 years, 95% CI: 59-64; male: 71%, 95% CI: 64-78%). The mortality estimated pooled prevalence was 19% (95% CI: 13-25, I2=100%, p<0.00001) and improvement estimated pooled prevalence was 71% (95% CI: 62-81). Factors associated with the mortality are the number of patients in intensive care unit, the number of patients requiring invasive ventilation and the sera C-reactive protein value before TCZ administration. We observed a reduction in the odds of mortality in TCZ-treated patients when compared to those treated with other therapies (OR=0.47, 95% CI: 0.22-0.98, p=0.004). CONCLUSIONS: This study showed that the mortality pooled prevalence in TCZ-treated patients is lower than the overall mortality reported in patients with severe COVID-19.