Early clinical outcomes with tocilizumab for severe COVID-19: a two-centre retrospective study

Severe COVID-19 (coronavirus disease 2019) is associated with elevated inflammatory markers, consistent with cytokine release syndrome (CRS). Tocilizumab is an interleukin-6 (IL-6) inhibitor effective in treating CRS secondary to chimeric antigen receptor T-cell (CAR T-cell) therapy. The efficacy of tocilizumab in treating COVID-19 is unknown. This was a retrospective cohort study conducted at two hospitals in northern New Jersey (USA). All patients treated with tocilizumab for confirmed or suspected COVID-19 between 10 March 2020 and 9 April 2020 at the study sites were included. The primary endpoint was clinical improvement on Day 7 after treatment as assessed by respiratory status. Univariate analysis compared data between those who improved and those who did not. A total of 45 severe and critically ill patients treated with tocilizumab for COVID-19 were evaluated. Of the 45 patients, 11 (24.4%), 22 (48.9%) and 12 (26.7%) patients improved, had no change or worsened by Day 7 after treatment, respectively. Lower white blood cell count and lactate dehydrogenase at the time of drug administration as well as shorter time from supplemental oxygen initiation to dosing were significantly associated with clinical improvement in the univariate analysis. In conclusion, tocilizumab administration was associated with a low rate of clinical improvement within 7 days in this cohort of severe and critically ill patients with COVID-19.