A Propensity-Matched Cohort Study of Tocilizumab in Patients With Coronavirus Disease 2019

To determine the impact of tocilizumab, a monoclonal antibody against the interleukin 6 receptor, on survival in patients with coronavirus disease 2019.

Design: Observational cohort study of patients hospitalized with coronavirus disease 2019 between March 1, 2020, and April 24, 2020. A propensity-matched (1:1) analysis was used to compare patients who received tocilizumab to controls who did not. Competing risk survival analysis was used to determine the primary outcome of time to mortality, and adjusted log-linear and logistic regression for secondary outcomes.

Setting: Three hospitals within the NYU Langone Health system in New York.

Patients: Consecutive adult patients hospitalized with coronavirus disease 2019.

Intervention: Tocilizumab 400-mg IV once in addition to standard of care or standard of care alone.

Measurements and main results: Data from 3,580 severe acute respiratory syndrome coronavirus 2 positive qualifying hospitalized patients were included, of whom 497 (13.9%) were treated with tocilizumab. In the analysis of tocilizumab-treated patients and matched controls, fewer tocilizumab-treated patients died (145/497, 29.2%) than did controls (211/497, 42.4%). In the adjusted competing risk regression model, tocilizumab therapy was associated with improved survival relative to controls (hazard ratio = 0.24, 95% CI = 0.18-0.33, p < 0.001). Tocilizumab-treated patients and controls had similar adjusted time to discharge from hospital (hazard ratio = 0.96, 95% CI = 0.78-1.17, p = 0.67). However, they had longer adjusted ICU length of stay (rate ratio = 3.1, 95% CI = 2.5-3.7, p < 0.001) and a higher adjusted infection rate (odds ratio = 4.18, 95% CI = 2.72-6.52, p < 0.001) than controls.

Conclusions: Tocilizumab therapy was associated with significantly improved survival in coronavirus disease 2019 patients. This survival benefit was associated with increased ICU length of stay and increased infection rate, even as more patients in the tocilizumab group were rescued from rapid death. A prospective, randomized, placebo-controlled trial is needed to confirm these findings.