Single versus multiple doses of Tocilizumab in critically ill patients with coronavirus disease 2019 (COVID-19): A two-center, retrospective cohort study.

Purpose: To evaluate the effectiveness and safety of the optimal tocilizumab dosing regimen.

Methods: A two-center, retrospective cohort study, for COVID19 critically ill patients admitted to the intensive care units (ICUs). We included critically ill patients aged 18 years or older who received tocilizumab during ICU stay. Patients were divided into two groups based on the number of the received tocilizumab doses. The primary outcome was the in-hospital and 30-day mortality. Propensity score (PS) matching was used (1:1 ratio) based on the selected criteria.

Results: A total of 298 patients were included in the study; 70.4% (210 patients) received a single dose of tocilizumab. After adjusting for possible confounders, the 30-day mortality (HR 0.79 95% CI 0.43-1.45 P = 0.44) and in-hospital mortality (HR 0.81; 95% CI 0.46-1.49; P = 0.53) were not significantly different between the two groups. On the flip side, patients who received multiple doses had higher pneumonia odds than a single dose (OR 3.81; 95% CI 1.79-8.12 P = 0.0005).

Conclusion: Repeating tocilizumab doses were not associated with a mortality benefit in COVID-19 critically ill patients, but it was associated with higher odds of pneumonia compared to a single dose.