Early use of low dose tocilizumab in patients with COVID-19: A retrospective cohort study with a complete follow-up

Background: Pneumonia with severe respiratory failure represents the principal cause of death in COVID-19, where hyper-inflammation plays an important role in lung damage. An effective treatment aiming at reducing the inflammation without preventing virus clearance is thus urgently needed. Tocilizumab, an anti-soluble IL-6 receptor monoclonal antibody, has been proposed for treatment of patients with COVID-19. Methods: A retrospective cohort study at the Montichiari Hospital, Brescia, Italy, was conducted. We included consecutive patients with COVID-19 related pneumonia at the early stage of respiratory failure, all treated with a standard protocol (hydroxychloroquine 400 mg daily, lopinavir 800 mg plus ritonavir 200 mg per day). We compared survival rate and clinical status in a cohort of patients who received additional treatment with tocilizumab once (either 400 mg intravenous or 324 mg subcutaneous) with a retrospective cohort of patients who did not receive tocilizumab (referred to as the standard treatment group). All outcomes were assessed at the end of the follow-up, that correspond to death or complete recovery and discharge from the hospital. Findings: 158 patients were included, 90 of which received tocilizumab. 34 out of 68 (50%) patients in the standard treatment group and 7 out of 90 (7.7%) in the tocilizumab group died. Tocilizumab significantly improved survival compared to standard care (multivariate HR: 0.057; 95% C.I = 0.017- 0.187, p < 0.001). No differences between the two administration routes of tocilizumab were observed. No tocilizumab-related infections and/or side effects were observed. Interpretation: Early treatment with tocilizumab could be helpful to prevent excessive hyper-inflammation and death in COVID-19 related pneumonia. Low dose administration of tocilizumab is not associated with adverse events. Funding: none