Benefit and risk associated with interleukin-6 receptor inhibitor administration during severe COVID-19: a retrospective multicentric study

During severe and critical COVID-19, therapeutic options remain scarce. Among interventions, the use of interleukin-6 receptor inhibitor (IL-6Ri) is especially controversial due to persistent uncertainty about their efficacy and safety. To compare the occurrence of secondary infections, digestive and hematological complication function of the administration of IL-6Ri we conducted a multicentric retrospective French observational study. All severe or critical COVID-19 requiring hospital admission were included. Among 2587 patients requiring hospital admission, 1603 had a severe COVID-19 and 984 a critical one requiring ICU admission. 224 received at least one dose of tocilizumab or sarilumab. Incidence of secondary infection was 29.5% in the IL-6Ri group vs. 19.5% without IL-6Ri (p = 0.0004) in the whole population. This result remained consistent after adjustment, without multiple imputation (MI) and after MI (adjusted OR: 1.47 [1.25; 1.72]; p < 0.0001)). Incidence of hematological or digestive complication were similar between groups. Mortality of patients admitted in ward was higher in the IL-6Ri group (18.7% vs 10.5%, p = 0.0155). No difference in 28 days, ICU, hospital of 90 days mortality was noticed among ICU patients.Clinical trial registration: This study was registred on ClinicalTrial.gov: NCT05017441.