Cancer cells, by releasing pro-angiogenic factors, stimulate the growth of the 
thick capillary net necessary for the nourishment of the tumor mass. The battle 
to defeat cancer uses today different approaches based on the inhibition of 
pathological angiogenesis: several compounds, either synthetic or biotech, aimed 
at this complex process, are under development. Vascular endothelial growth 
factor (VEGF) is considered the main target for an anti-cancer therapy based on 
angiogenesis inhibition; the goal is to block the interaction between this 
cytokine and its receptors in order to stop the intracellular signaling pathways 
leading to endothelium remodeling. FDA recently approved two drugs specifically 
aimed at VEGF, bevacizumab, a humanized monoclonal antibody, and pegaptinib, a 
pegylated aptamer with application in ophthalmic pathologies. These two 
approvals validate anti-VEGF therapy for clinical use, and show how biotech 
companies are investing on angiogenesis using different approaches, i.e. 
exploiting protein drugs and oligonucleotide-based therapeutics. Monoclonal 
antibodies, as well as other high molecular weight products like cytokine-traps, 
aptamers and short interfering RNA (siRNA), are designed to target VEGF and its 
receptors. Their design, production and clinical advancement in cancer and other 
pathological conditions linked to angiogenesis will be specifically addressed in 
this review.