Recent years have seen many exciting developments in the treatment of rheumatoid 
arthritis. Tocilizumab (TCZ) is a monoclonal antibody which inhibits the 
interleukin-6 receptor. After initial studies in Japan, it has been extensively 
studied in five multicentre clinical trials. This report summarises the key 
efficacy and toxicity findings from the major clinical trials. TCZ works quickly 
and effectively in rheumatoid arthritis either as monotherapy or in combination 
with other agents in early disease, DMARD inadequate responders, seronegative 
disease and after anti-TNF failure. The toxicity profile is manageable but 
includes infections (most notably skin and soft tissue), increases in serum 
cholesterol, transient decreases in neutrophil count and abnormal liver function 
tests (especially in combination with methotrexate). In summary, there is 
sufficient evidence to make TCZ a first line biologic therapy for rheumatoid 
arthritis especially for those who are unable to take methotrexate or who fail 
anti-TNF therapy.