Tocilizumab Therapy of COVID-19: A Comparison of Subcutaneous and Intravenous Therapies

Background The release of pro-inflammatory cytokines, resulting in cytokine storm syndrome, contributes to the morbidity and mortality associated with COVID-19 disease This study aimed to compare the effects of intravenous (IV) and subcutaneous (SC) tocilizumab, an IL-6 receptor antagonist, on respiratory parameters and clinical outcome in patients with COVID 19 Methods We performed a retrospective cohort study of hospitalized patients with COVID-19 treated with either IV or SC tocilizumab from March 26, 2020 to May 18, 2020 Respiratory parameters seven days after receiving tocilizumab therapy were compared to baseline measurements All patients were assessed until discharged from the hospital Results Tocilizumab was administered to 125 patients: 65 received IV and 60 received SC therapy At day seven, 52% of the patients in the IV group demonstrated improvement in respiratory parameters, compared to 28% in the SC group (P = 0 01) Mortality rates at days seven and 28 were 15% and 37%, respectively in the IV group and 17% and 50%, respectively in the SC group (P = NS) In-hospital mortality rate was 38% for the IV group versus 57% for the SC group (P = 0 04) More than 90% of patients in each group received corticosteroids, however significantly more patients in received convalescent plasma in the IV group Conclusions At the doses used in this study, IV tocilizumab is preferred over SC therapy for the treatment of cytokine storm syndrome due to COVID-19