key: cord-0767609-jcxz8wqh
authors: De Oliveira, Bruno; Mallat, Jihad
title: Efficacy of Tocilizumab for treatment of severe COVID-19 Pneumonia: more evidence is needed
date: 2020-09-04
journal: Clin Infect Dis
DOI: 10.1093/cid/ciaa1284
sha: 6082e0cf5dc1e3dbadab21ada33e4f5c474dafb0
doc_id: 767609
cord_uid: jcxz8wqh

nan

M a n u s c r i p t During the current COVID19 pandemic, many different drugs, ranging from previously available antiviral drugs, cytokine inhibitors, glucocorticoids, and other inflammation modulators have been used empirically and are simultaneously being evaluated in clinical trials. The cytokine storm that these patients are prone to in the more severe cases is well documented (2) and is considered one of the more promising targets of treatment. We agree and applaud the decision to use serial C-reactive protein measurements to assess the efficacy of interleukin-6 receptor blockade, even if these results are not surprising since that is the established function of tocilizumab (4) . We also accept that this cohort of patients unquestionably exhibited a lowering of inflammatory markers following the administration of the drug.

However, we cannot agree with the authors' conclusion regarding the benefits of tocilizumab, and in our opinion, this is a methodological misstep. One cannot establish in any way an association between the use of the drug and improvement of oxygenation, reduction of vasopressor support, or success in liberation from mechanical ventilation without a control arm to a study. Also, the decreases in norepinephrine requirements and the need for mechanical ventilation between before and after tocilizumab administration were not statistically tested. Furthermore, there is a doubt about the appropriateness of the statistical analysis. Since most of the variables were not normally distributed, a non-parametric test (Wilcoxon signed-rank test) should have been used for paired comparisons instead of the paired t-test.

Moreover, the low mortality rate (7.4%) observed in Jordan's study in comparison with data from Wuhan, (5), Seattle (6), and Vitoria-Gasteiz (7), as mentioned by the authors cannot be attributed to the use of tocilizumab. The authors' conclusion that the use of tocilizumab may lead to clinical improvement, recovery from respiratory failure, and prevention of death is speculation and not supported by the study results.

In summary, the retrospective design, the absence of a control group, and the minimal sample size are the significant limitations that preclude any conclusion from this study and do not

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