Prof Alberto Sobrero speaks about some key clinical studies on colorectal cancer which were presented at ESMO 2010. Two of these trials looked at cediranib, an inhibitor of VEGF receptor tyrosine kinase, however these large scale trials did not show superiority. A separate trial involving just 200 patients assessed the hedgehog inhibitor GDC-0449, but this drug was also found not to be superior to present treatments. Prof Sobrero discusses the benefits of smaller scale trials at this stage of drug evaluation and outlined the final study which assessed the efficacy of different cetuximab regimens. This study produced surprising results and Prof Sobrero explains why these should be interpreted as evidence that cetuximab should not be used with oxaliplatin.