Abstract
Background: The use of IL-6 blocking agents has been proposed as a therapeutic option for COVID-19 pneumonia in view of the involvement of this cytokine in inflammation. Tocilizumab is the most widely evaluated IL-6 blocker within this context. In this review we looked at the evidence for safety, efficacy and outcomes of tocilizumab treatment for COVID-19 pneumonia.
Methods: A systematic search in PubMed, covering 2020 and part of 2021, yielded a sample of 19 randomized clinical trials. The present review was conducted and reported following PRISMA-IPD guidelines.
Results: The selected trials were conducted in Europe (n=6; 31.5%), Asia (n=6; 31.5%), multiple continents (n=3; 15.7%), North America (n=2; 10.5%), South America (n=1; 5.2%), and Africa (n=1; 5.2%), evaluating 7,961 adult patients, of whom 4,061 received tocilizumab and 3,630 received standard care or placebo. Tocilizumab reduced mortality in most patients (n=2985; 87.9%). Benefits were also observed with regard to hospital discharge (2 trials; one of them had a cohort of 2022 tocilizumab users, of whom 56% were benefited; the other had a cohort of 350 tocilizumab users, whom were benefited in a hazards ratio of 1.44), clinical outcomes (2 trials, with a total of 392 patients, perceived tocilizumab in a positive manner [n=350/HR=1.44 and n=42/83,3%]; 4 trials saw no benefit [n=73/39% and n=294/OR=1.26]), and the composite outcome of mechanical ventilation and death (n=2003; 32%). Patients undergoing treatment with tocilizumab and controls did not differ significantly with regard to adverse events.
Conclusion: Tocilizumab reduced the need for mechanical ventilation in hospitalized patients and improved clinical parameters. The ability of tocilizumab to reduce mortality remains uncertain. The groups displayed similar levels of adverse effects.