A recombinant, humanized IgG1 monoclonal antibody directed against the interleukin-6 receptor (IL-6R) with immunosuppressant activity. Tocilizumab targets and binds to both the soluble form of IL-6R (sIL-6R) and the membrane-bound form (mIL-6R), thereby blocking the binding of IL-6 to its receptor. This prevents IL-6-mediated signaling. Il-6, a pro-inflammatory cytokine that plays an important role in the regulation of the immune response, is overproduced in autoimmune disorders and certain types of cancers.