Tocilizumab is a humanized anti-IL-6 receptor monoclonal antibody, which binds 
to circulating soluble IL-6 receptor and membrane-expressed IL-6 receptor, 
inhibiting IL-6 binding to both forms of IL-6 receptor. Several Phase III 
clinical trials demonstrate the clinical efficacy of tocilizumab as monotherapy 
or with disease-modifying anti-rheumatic drugs for adult patients with 
moderately to severely active rheumatoid arthritis. Tocilizumab in combination 
with methotrexate after 24 weeks of treatment could induce disease remission in 
30% of patients with rheumatoid arthritis refractory to anti-TNF antagonist 
therapy. The most common adverse reactions reported in clinical studies are 
upper respiratory tract infection, nasopharyngitis, headache, hypertension and 
mild, reversible increases in alanine aminotransferase enzymes. Serious adverse 
reactions include infections, gastrointestinal perforations and hypersensitivity 
reactions, including anaphylaxis. The clinical efficacy and safety of 
tocilizumab has led to the approval of this innovative drug for the treatment of 
rheumatoid arthritis in more than 70 countries worldwide.