Objective: This observational study aimed to determine optimal timing of interleukin-6 receptor inhibitors (IL6ri) administration for Coronavirus disease 2019 (Covid-19).
Methods: Patients with Covid-19 were given an IL6ri (sarilumab or tocilizumab) based on iteratively reviewed guidelines. IL6ri were initially reserved for critically ill patients, but after review, treatment was liberalized to patients with lower oxygen requirements. Patients were divided into 2 groups: those requiring ≤ 45% fraction of inspired oxygen (FiO2) (termed stage IIB) and those requiring >45% FiO2 (termed stage III) at the time of IL6ri administration. Main outcomes were all-cause mortality, discharge alive from hospital, and extubation.
Results: 255 Covid-19 patients were treated with IL6ri (149 stage IIB and 106 stage III). Patients treated in stage IIB had lower mortality than the stage III group (adjusted hazard ratio [aHR]: 0.24; 95% confidence interval [CI] 0.08-0.74). Overall, 218 (85.5%) patients were discharged alive. Patients treated in stage IIB were more likely to be discharged (aHR: 1.43; 95% CI 1.06 – 1.93) and were less likely to be intubated (HR: 0.43; 95% CI: 0.24-0.79).
Conclusions: IL6ri administration prior to greater than 45% FiO2 requirement was associated with improved Covid-19 outcomes. This can guide clinical management pending results from randomized control trials.