Interleukin (IL)-6 plays essential roles not only in the immune response, but also in haematopoiesis and the central nervous system. Deregulated production of IL-6 has been found in chronic inflammatory autoimmune diseases, such as rheumatoid arthritis (RA), systemic onset juvenile idiopathic arthritis (soJIA), Crohn's disease (CD) and systemic lupus erythematosus (SLE). Furthermore, IL-6 activities can explain many symptoms of these diseases. More importantly, serum levels of IL-6 are correlated with disease activity. Tocilizumab binds specifically 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.
A decrease in C-reactive protein (CRP) was noted as early as week 2. Changes in pharmacodynamic parameters were observed (i.e., decreases in rheumatoid factor, erythrocyte sedimentation rate (ESR), serum amyloid A and increases in hemoglobin) with both doses, however the greatest improvements were observed with 8 mg per kg tocilizumab. Similar pharmacodynamic changes were also observed in active polyarticular juvenile idiopathic arthritis and active systemic juvenile idiopathic arthritis patients.
Mihara M, Nishimoto N, Ohsugi Y: The therapy of autoimmune diseases by anti-interleukin-6 receptor antibody. Expert Opin Biol Ther. 2005 May;5(5):683-90. [PubMed:15934843 ]