Background: IL-6 is a pro-inflammatory cytokine with multiple roles in the pathogenesis of rheumatoid arthritis (RA). Targeting IL-6 with the humanized anti IL-6 receptor antibody tocilizumab was effective in several placebo-controlled clinical studies in RA.
Objectives: To address how clinically efficacious blockade of IL-6 signalling with inteleukin-6 receptor antibody is in RA patients and what the potential mode of action explaining tocilizumab activity in RA treatment could be.
Results/conclusion: IL-6 induces autoantibody-producing plasma cells and effector T cells and is implicated in the development of clinical signs and symptoms, including increased synthesis of acute phase reactants, fatigue, anaemia and anorexia. Its effects also included significant improvements in American College of Rheumatology (ACR)20, ACR50 and ACR70 values, as well as in health-related quality of life measures, compared with controls. Tocilizumab also prevents radiographic progression of joint damage. Tocilizumab is generally well tolerated and efficacious in patients refractive to conventional DMARD therapies.