Tocilizumab is an immunosuppressive drug, mainly for the treatment of rheumatoid arthritis (ra) and systemic juvenile idiopathic arthritis, a severe form of arthritis in children. it is a humanized monoclonal antibody against the interleukin-6 receptor (il-6r). interleukin 6 (il-6) is a cytokine that plays an important role in immune response and is implicated in the pathogenesis of many diseases, such as autoimmune diseases, multiple myeloma and prostate cancer.