What is angiogenesis?
Angiogenesis is the formation of new blood vessels. The process is controlled by certain
chemicals produced in the body. The word comes from 2 Greek words, angio meaning blood
vessel and genesis meaning beginning. Although this may help in normal wound healing,
cancer can grow when these new blood vessels are created. New blood vessels near the
cancer cells provide them with oxygen and nutrients. This allows the cancer cells
to multiply, invade nearby tissue, and spread to other areas of the body (metastasize).
What are angiogenesis inhibitors and how do they work?
A chemical that interferes with the signals to form new blood vessels is called an
angiogenesis inhibitor. Scientists have studied the effect of angiogenesis inhibitors
on certain kinds of tumors and cells. Several of the angiogenesis inhibitors are also
effective in treating an eye disease, macular degeneration.
Sometimes called antiangiogenic therapy, this treatment may prevent the growth of
cancer by blocking new blood vessels from forming. Angiogenesis inhibitor therapy
may stabilize the tumor and prevent it from growing further. Or it may reduce the
size of the tumor. More than a dozen medicines with antiangiogenic properties are
available in the U.S.
Some other cancer drugs are known to act in similar ways. Thalidomide and lenalidomide
have been identified as having mild activity as angiogenesis inhibitors.
An angiogenesis inhibitor medicine, bevacizumab, has been approved by the FDA to aid
in the treatment of glioblastoma, colorectal cancer, non-small cell lung cancer, liver
(hepatocellular) carcinoma, neuroendocrine tumors, and metastatic renal cell cancer.
Other antiangiogenesis therapies include sunitinib, sorafenib, pazopanib, and everolimus. Many
other angiogenesis inhibitors are now being studied as well.
Angiogenesis inhibitors have different side effects from most conventional cancer
chemotherapy medicines because they work very differently. Many chemotherapy medicines
kill healthy cells along with cancer cells. But angiogenesis inhibitors only prevent
new blood vessels from forming. The side effects from angiogenesis inhibitors are
generally less and milder than with conventional chemotherapy medicines. But some
of the side effects can be serious and include:
Angiogenesis inhibitors might also affect a developing unborn baby and are not recommended
for pregnant women or women who may become pregnant.