•International Journal of infectious disease 25th July 2020.

IL6ri therapy associated with improved Covid-19 outcomes
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Treatment benefit greatest when initiated early during disease course
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IL6ri therapy appears superior than remedesvir and dexamethasone

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.