Angiogenesis is the process of forming new blood vessels. It has been found that some cancerous tumours are very efficient at generating new blood vessels. This increases the amount of blood supplied to the tumour and allows it to grow rapidly.
Angiogenesis begins when cancer cells send signals to nearby tissues and activate growth factors that allow the tumour to form new blood vessels. Vascular endothelial growth factor (VEGF) is an example of such a molecule.
Angiogenesis inhibitors, or anti-angiogenic therapies, were developed by researchers to disrupt the growth process. Binding to VEGF molecules prevents these drugs from activating receptors on endothelial cells inside blood vessels. This is how bevacizumab works. Among its uses is the treatment of glioblastoma and cancers of the lung, kidney, breast, colon, and rectum.
Other angiogenesis inhibitors work by preventing VEGF receptors from sending signals to blood vessel cells. The drugs are known as tyrosine kinase inhibitors (TKIs). A tyrosine kinase inhibitor such as sunitinib is an example of this drug.
Although angiogenesis inhibitors work by cutting off the tumour’s blood supply, they do not destroy the tumour. Therefore, these drugs are typically used in conjunction with chemotherapy.
Inhibitors of angiogenesis are particularly effective in treating liver cancer, kidney cancer, and neuroendocrine tumours.