Antiangiogenesis refers to the process of inhibiting the formation of new blood vessels (angiogenesis). This concept is most commonly applied in cancer treatment, as tumors need to create new blood vessels to supply the nutrients and oxygen they require for growth and metastasis, which is the process by which cancer spreads to new locations in the body.

Antiangiogenic agents are drugs that inhibit angiogenesis. They work by blocking the signals that stimulate blood vessel growth, primarily those mediated by a molecule called vascular endothelial growth factor (VEGF). By preventing the growth of new blood vessels, these drugs aim to “starve” the tumor of its necessary nutrients and oxygen.

One of the first antiangiogenic drugs to be approved by the FDA (in 2004) was bevacizumab (Avastin), which is a monoclonal antibody that binds to VEGF, preventing it from stimulating new blood vessel growth.

While antiangiogenic therapy has proven effective in treating certain types of cancer, it’s not without its challenges. Some tumors can become resistant to antiangiogenic drugs, and these drugs can also have side effects, including high blood pressure, fatigue, and risk of bleeding. Moreover, they are not effective on their own for many types of cancer and are typically used as part of a combination treatment strategy with other types of cancer therapy.

As of my knowledge cutoff in September 2021, research is ongoing to develop new antiangiogenic agents and to better understand how to use these drugs most effectively in cancer treatment. For up-to-date information, please refer to the latest scientific literature or authoritative sources.