Effects of Tocilizumab in COVID-19 patients: a cohort study

Abstract

Background: Due to the lack of proven therapies, we evaluated the effects of early administration of tocilizumab for COVID-19. By inhibition of the IL-6 receptor, tocilizumab may help to mitigate the hyperinflammatory response associated with progressive respiratory failure caused by SARS-CoV-2. Methods: A retrospective, observational study was conducted on hospitalized adults who received intravenous tocilizumab for COVID-19 between March 23, 2020 and April 10, 2020. Results: Most patients were male (66.7%), Hispanic (63.3%) or Black (23.3%), with a median age of 54 years. Tocilizumab was administered at a median of 8 days (range 1-21) after initial symptoms and 2 days (range 0-12) after hospital admission. On the day of administration, the median PaO2/FiO2 was 166 (range 33-523) and 50 patients (83.3%) had ARDS. By day 30, 36 patients (60.0%) demonstrated clinical improvement, 9 (15.0%) died, 33 (55.0%) were discharged alive, and 18 (30.0%) remained hospitalized. Successful extubation occurred in 13 out of 29 patients (44.8%). Infectious complications occurred in 16 patients (26.7%) at a median of 10.5 days. There was an increase in PaO2/FiO2 and an initial reduction in CRP that was not sustained beyond day 10. Conclusions: Majority of patients demonstrated clinical improvement and were successfully discharged from the hospital alive after receiving tocilizumab. Similar to previous studies, infectious complications were not uncommon. We observed a rebound effect with CRP, which may suggest the need for higher or subsequent doses to adequately manage cytokine storm. Based on our findings, we believe that tocilizumab may have a role in the treatment of COVID-19, however randomized controlled studies are urgently needed.