Tocilizumab is a humanized recombinant monoclonal antibody of the IgG1 class, directed against the soluble IL-6 receptor (sIL-6R) and the membrane-bound receptor (mIL-6R). It is indicated for the treatment of moderate to severe rheumatoid arthritis, systemic juvenile idiopathic arthritis, polyarticular juvenile idiopathic arthritis, and for the treatment of cytokine release syndrome (CRS) induced by CAR-T lymphocytes. The mechanism of action is also associated with a cytokine “storm” characterized by increased plasma concentrations of various cytokines, including the pro-inflammatory cytokine interleukin-6 (IL-6), which plays a key role in the development of the aberrant immune response. There is a report from Chinese researchers, on 21 patients with severe or critical COVID-19 pneumonia treated with a single dose of tocilizumab 400 mg IV, a reduction in oxygen requirement, absorption of lung lesions, normalization of lymphocyte count, reduction in C-reactive protein levels, and discharge from the hospital were recorded. A randomized trial of tocilizumab was then launched in China. Even though, to be honest, the guidelines of the main international scientific societies (IDSA and NIH) do not recommend the routine use of monoclonal antibodies in clinical practice. Also in Italy, a study promoted by the Azienda Unità Sanitaria Locale-IRCCS of Reggio Emilia, concluded a few days ago, on 126 patients. The randomized study to evaluate the efficacy of tocilizumab, administered in the early phase, compared to standard therapy in patients with newly onset Covid-19 pneumonia requiring hospital care, but not invasive or semi-invasive mechanical ventilation procedures. This is the first randomized study completed internationally on tocilizumab, entirely carried out in Italy.

