Systematic review and meta-analysis of interleulin-6 inhibitors in reducing mortality for hospitalized patients with COVID-19

Abstract

Objective: One year after the declaration of the SARS-CoV-2 pandemic, only dexamethasone has clearly shown a reduction in mortality for COVID-19 hospitalized patients. For interleukin-6 inhibitors, results are variable and unclear. The objective was to review and analyze the effect of tocilizumab and sarilumab on survival in this setting. Method: The PRISMA statements were fulfilled for the systematic review. A systematic search in Medline, Embase and medRxiv was conducted to identify randomized controlled trials with tocilizumab or sarilumab in hospitalized patients with COVID-19. Mortality data from non-critical and critical patients were extracted. A random-effects (DerSimonian-Laird) meta-analysis was performed for both subgroups and the whole population using MAVIS software v. 1.1.3. Similarity and homogeneity among trials were assessed. Results: Twenty-five and 23 articles were identified in Medline and Embase, respectively, five were trials with tocilizumab and/or sarilumab; two more were identified at medRxiv. Seven randomized clinical trials fulfilled the inclusion criteria. Another trial was pre-published and included post-hoc. The meta-analysis, with eight randomized clinical trials and 6, 340 patients, showed a benefit on mortality for interleukin-6 inhibitor (hazard ratio 0.85; confidence interval 95% 0.74-0.99), low heterogeneity (I2 = 7%), but a low similarity among studies. The results showed no differences among critical and non-critical patients. A sensitivity analysis excluding non-similar or heterogeneous studies showed different results, without benefit and with low precision of the result in non-critical patients. Conclusions: A benefit in mortality for interleukine-6 inhibitors was found, but with important differences among the scenarios analyzed in the clinical trials. Positive results are mainly caused by two randomized clinical trials which are similar in concomitant use of steroids and very-high mortality in critical patents. Sarilumab was poorly represented in the meta-analysis. Nevertheless, an association between the benefit and the critical/non-critical condition was not found. More randomized clinical trials, mainly focused in patients at high mortality risk, are needed to confirm the benefit of interleukine-6 inhibitors for COVID-19. Sarilumab was underrepresented in the meta-analysis.