Cancer cannot grow or spread without new blood vessels that are produced in a process known as angiogenesis. Tumor angiogenesis is the growth of blood vessels from the surrounding tissue to a solid tumor, caused by the release of chemicals by the tumor. These new blood vessels "feed" the tumor with oxygen and nutrients, enabling it to grow and spread to nearby tissue and other parts of the body.

Anti-angiogenesis is the prevention of new blood vessel formation, thus "starving" cancer cells and ultimately inhibiting cancer development and growth.

Clinical trials for melanoma include investigation of the following angiogenesis inhibitors, a family of drugs able to prevent the growth of new blood vessels that supply tumors:

• Thalidomide is currently being studied for the treatment of several cancers, including advanced or metastatic melanoma. It is perhaps best known for its use as a sedative and anti-nausea drug for pregnant women in the 1950s. The drug caused severe birth defects and was taken off the market until it was approved for treatment of leprosy in 1996. Thalidomide has relatively few serious side effects when not taken by pregnant women. Clinical trials combining thalidomide and the chemotherapy drug temozolomide have shown some early encouraging results.^1,2
• Endostatin inhibits the growth of the cells that line blood vessels. It is currently being studied for the treatment of Stage IV melanoma. Clinical trials of endostatin as a single agent or in combination with interferon-alfa are in their early stages.
• Interferon is a biological agent whose multiple actions include potent anti-angiogenic function. Clinical trials of interferon as a single agent or in combination with other angiogenesis inhibitors, such as thalidomide and endostatin, are currently underway.

For more information on these types of investigations, please see Clinical Trials.