The survival advantage seen in colorectal cancer patients treated with bevacizumab has led researchers to search for other angiogenesis inhibitors that could have beneficial effects. Dr Johanna Bendell talks to ecancer.tv about some of the key advances in anti-angiogenesis therapies for colorectal cancer.

Although a large proportion of clinicians administer bevacizumab in combination with FOLFOX (folinic acid, fluorouracil and oxaliplatin), the weight of clinical evidence suggests that this combination is not as effective as bevacizumab and IFL (irinotecan, folinic acid and fluorouracil). Dr Bendell talks about research into VEGF receptor tyrosine kinase inhibitors. Although these agents had been hoped to provide an additional mechanism to combat colorectal cancer, they are known to affect multiple targets and therefore have higher levels of adverse effects. In addition to this, first and second line clinical trials published to date have failed to show beneficial effects.

More promising news has been the initial results for aflibercept (VEGF Trap) as a second line treatment for patients with metastatic colorectal cancer. This protein binds to not only VEGF-A but also VEGF-B and PIGF, and when administered with FOLFIRI chemotherapy (folinic acid, fluorouracil and irinotecan) reportedly produces improvements in both progression free and overall survival. Dr Bendell considers these results but stresses that their significance will not be fully understood until we appreciate the level of cross resistance between aflibercept and bevacizumab.