On June 29, 2011, an expert panel that advises the U.S. Food and Drug Administration (FDA) unanimously recommended removing the indication for 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 recommendation came after two days of hearings that were part of an appeal by Genentech, the company that makes Avastin. In December 2010, another expert panel made the same recommendation to remove the breast cancer indication for Avastin, and Genentech asked the FDA to reconsider.
Avastin was approved to treat metastatic breast cancer in 2008, but it wasn't a full approval. This meant the FDA wanted more research done on the benefits and risks of Avastin before it would consider full approval. It also meant that the initial conditional approval could be withdrawn if the research didn't convince the FDA that Avastin was ready for full approval.
The two expert panels that the FDA turned to for advice on Avastin's breast cancer indication reviewed detailed results of studies submitted to the FDA as part of the drug evaluation process. The panels also considered the opinions of many others, including doctors, patients, and patient advocacy organizations, before making the recommendations.
Both expert panels concluded that Avastin has not been shown to be safe and effective for treating metastatic breast cancer. So the experts recommended that the breast cancer indication should be withdrawn. The FDA doesn't have to follow the recommendation of the expert panels, but it usually does. Margaret Hamburg, FDA commissioner, will make the final decision about withdrawing the breast cancer indication for Avastin.
An FDA decision to withdraw the Avastin breast cancer indication will not affect the approvals of Avastin to treat advanced cancers of the lung, colon, and rectum.
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.
The FDA expert panels had the following concerns about using Avastin to treat metastatic, HER2-negative breast cancer:
- Although research showed that combining Avastin with one of several chemotherapy medicines increased 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 panels 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.
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, 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. 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're already getting Avastin and are responding to treatment, you may want to ask your doctor about the expert panel's recommendation. 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.
Stay tuned to Breastcancer.org Research News for more information on the final decision on Avastin.