ABSTRACT
Objectives IL-6 inhibitors are administered to treat hospitalized COVID-19 patients. In 2021, due to shortages, different dosing regimens of tocilizumab, and a switch to sarilumab, were consecutively implemented. Using real world data, we compare the effectiveness of these IL-6 inhibitors. Methods Hospitalized COVID-19 patients, treated with IL-6 inhibitors, were included in this natural-experiment study. Sixty-day survival, hospital- and ICU length of stay and progression to ICU or death were compared between 8 mg/kg tocilizumab, fixed dose tocilizumab, low dose tocilizumab and fixed dose sarilumab treatment groups. Results 5485 patients from 49 hospitals were included. After correction for confounding, increased hazard ratios for 60-day mortality were observed for fixed dose tocilizumab (HR 1.20, 95% CI 1.04-1.39), low dose tocilizumab (HR 1.12, 95% CI 0.97-1.31) and sarilumab (HR 1.24, 95% CI 1.08-1.42), all relative to 8 mg/kg. The 8 mg/kg dosing regimen had lower odds for progression to ICU or death. Both hospital- and ICU length of stay were shorter for low dose tocilizumab than for the 8 mg/kg group. Conclusions We found differences in the probability of 60-day survival and the incidence of the combined outcome of mortality or ICU admission, mostly favoring 8 mg/kg tocilizumab. Because of potential time associated residual confounding, further clinical studies are warranted.
ABSTRACT
OBJECTIVES: Interleukin (IL)-6 inhibitors are administered to treat patients hospitalized with COVID-19. In 2021, due to shortages, different dosing regimens of tocilizumab, and a switch to sarilumab, were consecutively implemented. Using real-world data, we compare the effectiveness of these IL-6 inhibitors. METHODS: Hospitalized patients with COVID-19, treated with IL-6 inhibitors, were included in this natural experiment study. Sixty-day survival, hospital- and intensive care unit (ICU) length of stay, and progression to ICU or death were compared between 8 mg/kg tocilizumab, fixed-dose tocilizumab, low-dose tocilizumab, and fixed-dose sarilumab treatment groups. RESULTS: A total of 5485 patients from 49 hospitals were included. After correction for confounding, increased hazard ratios (HRs) for 60-day mortality were observed for fixed-dose tocilizumab (HR 1.20, 95% confidence interval [CI] 1.04-1.39), low-dose tocilizumab (HR 1.12, 95% CI 0.97-1.31), and sarilumab (HR 1.24, 95% CI 1.08-1.42), all relative to 8 mg/kg. The 8 mg/kg dosing regimen had lower odds of progression to ICU or death. Both hospital- and ICU length of stay were shorter for low-dose tocilizumab than for the 8 mg/kg group. CONCLUSION: We found differences in the probability of 60-day survival and the incidence of the combined outcome of mortality or ICU admission, mostly favoring 8 mg/kg tocilizumab. Because of potential time-associated residual confounding, further clinical studies are warranted.