Recent years have seen many exciting developments in the treatment of 
inflammatory arthritis. Tocilizumab (TCZ) is a compound that inhibits the IL-6 
receptor. Following initial studies in Japan, it has been extensively studied in 
five multicenter clinical trials. This report concentrates on the Actemra Versus 
Methotrexate Double-blind Investigative Trial in Monotherapy (AMBITION), which 
compared TCZ monotherapy (8 mg/kg every 4 weeks) with methotrexate monotherapy 
over 24 weeks. TCZ was shown to be the first biologic agent that is superior to 
methotrexate across a whole range of clinical outcomes measures with a rapid 
onset of effect. Significant liver toxicity was less common in the TCZ group. 
However, increases in lipids and decreases in neutrophils and skin infections 
were more common in the TCZ arm. Long-term efficacy and safety follow-up is 
ongoing. This trial supports the use of TCZ as monotherapy and suggests it 
should be regarded as a first-line biologic therapy.