Sarilumab is a human recombinant monoclonal antibody of the IgG1 subclass. Sarilumab is produced by recombinant DNA technology in Chinese Hamster Ovary cell suspension culture. Sarilumab binds to both soluble and membrane-bound IL-6 receptors (sIL-6R and mIL-6R), and has been shown to inhibit IL-6-mediated signaling through these receptors. IL-6 is a pleiotropic pro-inflammatory cytokine produced by a variety of cell types including T- and B-cells, lymphocytes, monocytes, and fibroblasts. IL-6 has been shown to be involved in diverse physiological processes such as T-cell activation, induction of immunoglobulin secretion, initiation of hepatic acute phase protein synthesis, and stimulation of hematopoietic precursor cell proliferation and differentiation. IL-6 is also produced by synovial and endothelial cells leading to local production of IL-6 in joints affected by inflammatory processes such as rheumatoid arthritis. Based on encouraging results in China with a similar drug, tocilizumab, a phase 2/3 US study evaluating efficacy and safety of sarilumab in patients hospitalized with severe COVID-19 was performed. At the moment, there are insufficient data to recommend either for or against use of sarilumab for hospitalized patients with COVID-19.