Tocilizumab fails survival benefit in severe COVID-19 – A retrospective cohort study

ABSTRACT

Objectives: Anti-interleukin-6 monoclonal antibody, tocilizumab, has produced mixed results in clinical trials for effectiveness against coronavirus disease 2019 (COVID-19). We conducted a retrospective cohort study to compare outcomes at 28 days of a cohort of patients with severe COVID-19 treated with tocilizumab and standard care, with those receiving standard care only. Materials and Methods: In this record-based retrospective cohort study, patients hospitalised with COVID-19 were classified into non-severe and severe disease as per institutional protocol. One cohort received tocilizumab with standard care and the second cohort received only standard care. Few patients also received high-dose steroids as ‘pulse’ steroids on initial clinical deterioration. Data were collected for the treatment given including oxygen interface, steroids, antimicrobials, duration of hospital stay in survivors, requirement of mechanical ventilation, and day of intubation from symptom onset. The primary outcome was to compare the all-cause mortality between the two groups. The effect of pulse steroid therapy on all-cause mortality was studied in the secondary outcome. Results: There was statistically significant mortality in the tocilizumab cohort as compared to standard care alone (HR 2.43, 95% CI 1.54–3.89). The need for mechanical ventilation was more in the tocilizumab cohort (85% vs. 18%, P < 0.001). Tocilizumab cohort had a delay in the day of intubation by a mean of 2.29 days from the day of symptom onset (P < 0.05). Pulse steroid administration showed increased all-cause mortality (HR 1.94, 95% CI 1.18–3.20) and risk of mechanical ventilation. Conclusion: Tocilizumab cohort showed higher mortality and need for mechanical ventilation in our study which contrasts the result of a few previous trials. Our study warrants the need for future clinical trials on this subject to ensure better treatment strategies in upcoming COVID-19 waves.