Exciting preclinical data have led scientists to a search for a "bypass in a test tube," a drug that stimulates the growth of blood vessels. However, efforts in the past year to stimulate angiogenesis in patients have been discouraging. "We need to go back to the lab and do some more preclinical experiments and gain a better understanding of the mechanism," says Napoleone Ferrara of the department of molecular oncology at Genentech Inc., South San Francisco, Calif.
When the leg or heart arteries are blocked, the tissues suffer an injury called ischemia from lack of oxygen. Restoring blood flow to the ischemic area is the most effective way to relieve symptoms, such as pain, and reduce long-term risk of heart attack. The body's natural healing process may initiate development of collateral circulation through angiogenesis. When the body's effort to restore blood flow fails or is insufficient, doctors intervene with either ...