Bevacizumab (Avastin®)

Bevacizumab (Avastin®)

Tumors need to develop and maintain new blood vessels to grow. Drugs that target these
blood vessels are helpful against a variety of cancers, and have been studied for use in
breast cancer.
Bevacizumab is a monoclonal antibody that has been used in patients with metastatic
breast cancer. This antibody is directed against vascular endothelial growth factor, a
protein that helps tumors form new blood vessels.
Bevacizumab is given by intravenous (IV) infusion. It is most often used in combination
with chemo.
Rare, but possibly serious side effects include bleeding, holes forming in the colon
(requiring surgery to correct), and slow wound healing.
More common side effects include high blood pressure, tiredness, blood clots, low white
blood cell counts, headaches, mouth sores, loss of appetite, and diarrhea. High blood
pressure is very common, so it very important that your doctor watches your blood
pressure carefully during treatment.
Bevacizumab was first approved by the US Food and Drug Administration (FDA) as part
of the treatment for metastatic breast cancer in 2008. The approval was based on a study
in which the women who received bevacizumab with the chemo drug paclitaxel (Taxol)
had a longer time without their cancers growing than the women who received paclitaxel
alone.
New study results that were presented at a July 2010 FDA meeting did not show a real
benefit for the women receiving bevacizumab as a part of their treatment. Although
bevacizumab seemed to slow cancer growth for a short-time in some of the women, it
didn't help them live longer. Those given bevacizumab also had much more severe side
effects. The FDA concluded that in the treatment of metastatic breast cancer, the risks of
this drug outweigh the benefits. On November 18, 2011, the FDA withdrew the breast
cancer "indication" for bevacizumab. This does not mean that the drug will become
unavailable, since it is still FDA-approved to treat some other cancers. It does mean that
the company making bevacizumab can’t market the drug for breast cancer—the company
can’t tell doctors or patients that the drug is useful in treating breast cancer. At this time,
women who are taking bevacizumab can continue to do so, but they should discuss this
treatment with their doctors