Anti-angiogenesis drugs work by blocking the activity of vascular endothelial growth factor (VEGF) to prevent the growth of new capillaries into the tumor and thereby sustain tumor growth. They have significantly changed the landscape of oncology because of their effectiveness and their associated toxicities. There have been several new biologic agents that have been approved and more are coming down the pipeline. Here are a few agents that come to mind:
- Avastin (bevacizumab) is a monoclonal antibody that inhibits angiogenesis and it was approved in 2004. In fact, it was the first agent approved by the FDA to inhibit angiogenesis. Avastin targets vascular endothelial growth factor (VEGF).
- Cediranib (tentative trade name Recentin), also known as AZD2171, is a potent inhibitor of vascular endothelial growth factor (VEGF) receptor tyrosine kinases.
- Vatalanib (PTK/ZK) is a small molecule tyrosine kinase inhibitor with broad specificity that targets all VEGF receptors (VEGFR), the platelet-derived growth factor receptor, and c-KIT.
- Sorafenib (Nexavar) is a multitargeted small molecule that inhibits VEGFR2, FLT3, PDGFR, and fibroblast growth factor receptor-1.
- The list goes on, but I'm going to stop here. This is a blog, not a medical review paper.
It's exciting to see advances in cancer therapy, but in the spirit of recent healthcare reform discussions, I must ask, "who gets to decide how much (in terms of dollars) therapy a cancer patient should receive?" These biologic agents are very expensive and many patients are having tremendous difficulty paying for them. At what point does it make sense to deny coverage for therapy simply because it's too expensive? Never? I'm glad to I don't work in a managed care organization because these are some of the ethical issues that must get discussed on both an individual and a population level.