Decreased mortality in COVID-19 patients treated with Tocilizumab: a rapid systematic review and meta-analysis of observational studies

BACKGROUND: We systematically reviewed the literature to answer the following research questions: 1) does IL-6 (receptor) antagonist therapy reduce mortality in COVID-19 patients compared to patients not treated with IL-6 (receptor) antagonists and 2) is there an increased risk of side effects in COVID-19 patients treated with IL-6 (receptor) antagonists compared to patients not treated with IL-6 (receptor) antagonists?. METHODS: We systematically searched PubMed, PMC PubMed Central, MEDLINE, WHO COVID-19 Database, Embase, Web-of-Science, COCHRANE LIBRARY, Emcare and Academic Search Premier (until June 30th2020). Random effects meta-analysis was used to pool the risk ratio and risk difference of individual studies. Risk of bias was appraised using the MINORS checklist. RESULTS: The search strategy retrieved 743 unique titles of which 10 studies (all on tocilizumab) comprising 1358 patients were included. Nine out of ten studies were considered to be of high quality. Meta-analysis showed that the tocilizumab group had lower mortality than the control group. The risk ratio (RR) was 0.27 95%CI 0.12 to 0.59 and the risk difference (RD) was 12% 95%CI 4.6% to 20% in favour of the tocilizumab group. With only a few studies available there were no differences observed regarding side effects. CONCLUSIONS: Our results showed that mortality was 12% lower for COVID-19 patients treated with tocilizumab compared to COVID-19 patients who were not treated with tocilizumab. The number needed to treat was 11, suggesting that for every 11 (severe) COVID-19 patients treated with tocilizumab 1 death is prevented. These results require confirmation by randomized controlled trials.