Tocilizumab (TCZ; RoActemra® or Actemra®) is a recombinant humanized monoclonal 
antibody that acts as an interleukin 6 (IL-6) receptor antagonist. For 
rheumatoid arthritis (RA), intravenous (IV) TCZ 8 mg/kg every 4 weeks has been 
approved since 2008 in Japan (where it is also approved for polyarticular 
juvenile idiopathic arthritis, systemic-onset juvenile idiopathic arthritis and 
Castleman's disease), and since 2009 in Europe in combination with methotrexate 
(MTX) for the treatment of moderate to severe active RA in adult patients with 
inadequate response to, or intolerance of, disease-modifying antirheumatic drug 
(DMARD) or tumor necrosis factor (TNF) antagonist therapy. It may also be 
administered as monotherapy in the same dose regimen in patients with 
methotrexate intolerance or with inadequate response to MTX. Since January 2011 
in the United States, the indication for treatment with TCZ for RA patients with 
an inadequate response to one or more TNF antagonists was extended to patients 
with moderately to severely active RA, and the recommended starting dose is 4 
mg/kg every 4 weeks, with an increase to 8 mg/kg based on clinical response. All 
of these approvals are based on the effectiveness and safety of the 8 mg/kg dose 
regimen when administered either as monotherapy or in combination with 
conventional DMARDs in well-designed clinical studies in adult patients with 
moderate to severe RA. TCZ at this dose is more effective than placebo, MTX or 
other DMARDs in reducing disease activity and improving health-related quality 
of life (HR-QoL). Although there were fewer responses with the 4 mg/kg dose, 
this dose every 4 weeks was not statistically different to 8 mg/kg when 
administered in combination with MTX, and this dose is the recommended starting 
dose in the US. Both doses have also been shown to inhibit structural joint 
damage in patients with an inadequate response to MTX. Thus, TCZ is an important 
new treatment option in patients with moderate to severe RA.