Tocilizumab: A retrospective multi-center cohort study of critically ill patients with COVID-19

Background: Coronavirus disease 19 (COVID-19) can have a severe presentation characterized by a dysregulated immune response requiring admission to the intensive care unit (ICU). Immunomodulatory treatments like tocilizumab were found to improve inflammatory markers and lung injury over time. We aim to evaluate the effectiveness of tocilizumab treatment on critically ill patients with severe COVID-19. Materials and methods: We conducted a multi-center retrospective cohort study of 154 adult patients admitted to the ICU for severe COVID-19 pneumonia between March 15 and May 8, 2020. Data were obtained by electronic medical record (EMR) review. The primary outcome of interest was mortality. Results: Of 154 patients, 34 (21.4%) received tocilizumab. Compared to the non-treated group, the treated group was significantly younger, had fewer comorbidities, lower creatinine and procalcitonin levels, and higher alanine aminotransferase levels on admission. The treated group was more likely to receive supportive measures in the context of critical illness. The overall case fatality rate was 71.4%, and it was significantly lower in the treated than the non-treated (52.9 vs. 76.7%, p = 0.007). In multivariable survival analysis, tocilizumab treatment was associated with a 2.1 times lower hazard of mortality when compared to those who were not treated (hazard ratio: 0.47; 95% CI: 0.27, 0.83; p = 0.009). The prevalence of secondary infection was higher in the treated group compared to the non-treated without significant difference (p = 0.17). Conclusion: Tocilizumab treatment for critically ill patients with COVID-19 resulted in a lower likelihood of mortality.