Angiogenesis is important to the growth and spread of cancers, as new blood vessels are critical to tumor formation. In animal studies, angiogenesis inhibitors have successfully stopped the formation of new blood vessels, causing tumors to shrink and die. Various angiogenesis inhibitors have been evaluated in human clinical trials. Participants in these studies include patients with cancers of the breast, prostate, brain, pancreas, lung, stomach, ovary, and cervix; patients with certain leukemias and lymphomas; and those with AIDS-related Kaposi sarcoma.
Antibodies against vascular endothelial growth factor (VEGF), which promotes vascular proliferation, have proved effective in cancer therapy. Bevacizumab, a humanized monoclonal antibody directed against VEGF-A, was the first angiogenesis inhibitor approved for the treatment of cancer in the United States. It has demonstrated clinical efficacy in the treatment of colorectal and other solid tumors and, on an off-label basis, in the treatment of neovascular (“wet”) age-related macular degeneration (AMD). Bevacizumab is also effective in the treatment of optic nerve gliomas in children. Tyrosine kinase inhibitors (TKIs), including pazopanib, have also shown promise in antitumor activity use; TKIs interfere with the modulation of growth factor signaling and thus inhibit angiogenesis. Aflibercept is a recombinant fusion protein that functions as a decoy receptor for VEGF. This agent inactivates VEGF-A, VEGF-B, and placental growth factor and is effective in the treatment of colorectal cancer and neovascular AMD.
Avery RA, Hwang EI, Jakacki RI, Packer RJ. Marked recovery of vision in children with optic pathway gliomas treated with bevacizumab. JAMA Ophthalmol. 2014;132(1):111–114.
Excerpted from BCSC 2020-2021 series: Section 1 - Update on General Medicine. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.