Early use of tocilizumab in hospitalized patients with severe and critical COVID-19 in the Province of Buenos Aires: a multicentric study

Background: Tocilizumab (TCZ), an IL-6 receptor antagonist monoclonal antibody is warranted in severe and critically-ill COVID-19 patients. The objective was to evaluate 28-day mortality of patients with severe or critical COVID-19 treated with early vs delayed TCZ.

Methods: Multicenter, retrospective cohort study including patients >18 years hospitalized between 7/1/2021-8/1/2022 with confirmed COVID-19, with 5, 6 and 7 points of WHO Ordinal Initial Severity Scale [SS]. Early or late administration was considered if TCZ was administered before or after 48 hours from admission. Outcomes were 28-day mortality and change of SS. Factors related to 28-day mortality were evaluated with Cox regression.

Results: 266 patients were included, 159(60%) male; aged 58(± 15); frequent comorbidities were hypertension (42%), obesity (37%) and diabetes (27%). Seventy patients had a SS = 5 (Supplemental O2), 143 had SS = 6 (NIV/ HFNC), and 53 had SS = 7 (IMV). 28-day mortality was 42%(112/266); predictors were age, obesity, higher SS, days between hospitalization and TCZ administration, and fewer days between symptoms onset and TCZ. Mortality of SS 5, 6 and 7 was 26%, 39% and 72% respectively. Compared with baseline SS points, 76% and 62% of patients remained stable or improved on days 3 and 7 since TCZ administration. 28-day mortality was lower when TCZ was administered before 48 hours (39% vs 57%; p = 0.02; HR = 0.63;[0.41-0.99, p = 0.05]).

Conclusions: This study supports the early use of TCZ in patients with severe or critical COVID-19.