Tocilizumab in Treatment of Severe COVID-19 Patients: A Systematic
Review and Meta-Analysis of Cohort Studies
Abstract
Background: There is an urgent need to improve health outcomes among
severe COVID-19 patients. Therefore, this study aimed to demystify
efficacy and safety of tocilizumab among those patients based on the
best available evidence. Methods: Nine electronic databases were
searched for relevant studies by three authors in July using search
terms “tocilizumab”, “COVID”, “SARS”. The last date checked was 26
August, 2020. Eligible studies were assessed through an inclusion
criterion focused on cohort studies and severe COVID-19 adult patients.
Any disagreement between the authors was resolved by discussions.
Primary outcomes were mortality and clinical improvement, while
secondary outcomes were tocilizumab-related adverse effects. Results:
Tocilizumab reduced the mortality rate by 41%, 40%, 28%, and 37% in
7, 14, 21, and 28 days. There was neither statistically significant
difference between the tocilizumab group and the control group in the
clinical improvement (pooled risk ratio1.21 [0.89, 1.64]) nor in
respiratory support change. There were no difference between the two
groups in the occurrence of serious adverse events (pooled risk
difference 0.00 [-0.02, 0.03]), bacteremia (pooled risk ratio 1.25
[0.80, 1.97]), elevation of liver functions (pooled risk difference
-0.00 [-0.03, 0.02]) and infusion related reactions (pooled risk
difference 0.01 [-0.02, 0.03]). However, the occurrence of
neutropenia (pooled risk ratio 9.23 [1.06, 80.24]) and new
infections (pooled risk difference 0.07 [0.00, 0.14]) were more
likely in the tocilizumab group. Conclusion: Because of the reported
adverse effects of tocilizumab in treating severe COVID-19 patients, the
use of that biological agent should be limited to selected patients
based on the best available evidence.