Definition of Avastin
Avastin: The first drug in a
new class designed to treat cancer by compromising its blood supply. Avastin (bevacizumab) is believed to prevent
angiogenesis, the
formation of new blood vessels that supply the tumor with blood, oxygen and other nutrients and allow the tumor to grow and metastasize to
other sites in the body. Additionally, Avastin may interfere with tumor growth
by causing blood vessels to shrink away from a tumor.
Avastin is a monoclonal antibody, a
type of genetically engineered protein
that binds to another protein called vascular endothelial growth factor (VEGF), which stimulates the growth of blood vessels. Blocking VEGF
is thought to be the mechanism by which Avastin cuts off the supply of vessels
that spring up to feed a tumor. Avastin is also believed to cause changes in the
existing blood vessels that may enhance the effect of traditional chemotherapy
drugs.
Avastin was approved by the FDA in 2004 for the
treatment of patients with metastatic colorectal cancer (colon cancer that has
spread to other parts of the body distant from the site of the original tumor).
Avastin is given along with traditional chemotherapy to treat metastatic
colorectal cancer.
In 2006, Avastin was approved by the FDA for use in
combination with chemotherapy for the first-line treatment of patients with
inoperable, locally advanced, recurrent or metastatic non-squamous, non-small cell lung cancer
(NSCLC), the most common type of lung cancer. This drug is the first
FDA-approved treatment to extend the survival of patients with this type of
advanced lung cancer to beyond one year.
Research is ongoing to determine if Avastin may be successfully used as well
to treat other types of cancer.
Last Editorial Review: 10/16/2006
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