A panel of oncology experts that advises the U.S. Food and Drug Administration (FDA) voted against continuing the approval of Avastin (chemical name: bevacizumab) in combination with Taxol (chemical name: paclitaxel) to treat metastatic, HER2-negative breast cancer that hasn't been treated with chemotherapy. The expert panel, known as the Oncology Drug Advisory Committee (ODAC), voted 12 against and one for continuing the current approval. The ODAC panel also voted unanimously against approving Avastin in combination with other chemotherapy medicines to treat metastatic breast cancer.
The FDA considers the ODAC recommendations as well as research results when making a final decision about whether to continue the current approval or grant a new approval for a cancer treatment. The FDA doesn't have to follow ODAC recommendations, but usually does. These new ODAC recommendations are only about using Avastin to treat metastatic breast cancer. Avastin is approved by the FDA to treat advanced-stage lung, colon, and kidney cancer; those approvals aren't being reconsidered.
Avastin is a targeted therapy medicine that is given intravenously. Avastin works by blocking the growth of new blood vessels that cancer cells need to grow and function. A protein called vascular endothelial growth factor (VEGF) makes new blood vessels grow in cancer cells. Avastin blocks the VEGF protein.
ODAC experts had the following concerns about using Avastin to treat metastatic breast, HER2-negative cancer:
- although research showed that combining Avastin with one of several chemotherapy medicines lengthened the time before the cancer grew or spread (progression-free survival), this benefit was small and overshadowed by the risk of serious side effects
- adding Avastin to chemotherapy didn't increase overall survival -- this means that women lived for about the same amount of time whether or not they got Avastin; the experts felt that the small improvement in progression-free survival with no improved overall survival wasn't a meaningful benefit, especially when the risk of serious side effects was considered
- adding Avastin to chemotherapy didn't ease metastatic breast cancer symptoms
Side effects of Avastin include high blood pressure, bleeding (nosebleeds, for example), and extra protein in the urine. People treated with Avastin also may have weakness, pain, and diarrhea. Avastin also may cause other serious side effects, including a higher risk of stroke or heart problems, kidney malfunction, and reduced white blood cell count (neutropenia), which can increase the risk of serious infection.
Based on the ODAC vote, it's likely that the FDA will no longer approve using Avastin to treat metastatic breast cancer (a final decision is expected in September 2010). Still, many doctors believe that the benefits of Avastin for certain women diagnosed with metastatic breast cancer are worth the risks and cost of treatment. Doctors can choose to use Avastin to treat metastatic breast cancer whether or not that particular use is officially approved by the FDA. Still, the loss of approval can make it less likely that insurers will pay for Avastin to treat breast cancer.
If you've been diagnosed with metastatic breast cancer, you and your doctor will develop a treatment plan that will likely include chemotherapy and possibly hormonal therapy and/or targeted therapy medicines such as Avastin. No matter which treatments are recommended for you, you may want to talk to your doctor about:
- why each treatment is recommended (including any combinations)
- treatment timing and sequence
- the expected benefits, risks, and side effects of each treatment
If you are already getting Avastin and are responding to treatment, ask your doctor about the ODAC recommendations. It's likely that your doctor will recommend that you stick with your treatment plan unless it stops being effective or unacceptable side effects develop.
You can learn more about Avastin in the Breastcancer.org Targeted Therapies section.
Stay tuned to Breastcancer.org Research News for updates on the FDA decision regarding Avastin.