Date of presentation: December 7, 2012
Among women with operable, triple-negative breast cancer, adjuvant (post-surgery) treatment with a combination of chemotherapy and Avastin® (bevacizumab) was no more effective than chemotherapy alone. These results were presented at the 2012 San Antonio Breast Cancer Symposium.
Avastin is a targeted therapy that blocks a protein known as VEGF. VEGF plays a key role in the development of new blood vessels that contribute to cancer growth. Avastin is used to treat selected patients with lung cancer, colorectal cancer, kidney cancer, or glioblastoma.
Previously, Avastin was also approved for breast cancer, but this approval was revoked in 2011. Avastin was originally approved for breast cancer under the US Food and Drug Administration’s accelerated approval program. The accelerated approval program provides earlier access to promising drugs for life-threatening health conditions while confirmatory studies are conducted. The approval was for use of Avastin in combination with chemotherapy for women with metastatic, HER2-negative breast cancer. The approval was based on the finding that Avastin delayed the progression (worsening) of metastatic breast cancer. There was no evidence that Avastin improved overall survival.
After its approval for breast cancer, additional studies found that Avastin had only a small effect on rate of cancer progression and no effect on overall survival. The FDA concluded that the potential benefits of Avastin for breast cancer do not outweigh the risks. Risks of Avastin include severe high blood pressure; bleeding problems; the development of perforations (holes) in the nose, stomach, and intestines; and heart attack or heart failure. It remains possible that Avastin will be found to benefit specific subgroups of breast cancer patients, and the FDA noted that it is open to considering data from additional studies that address this question.
To evaluate Avastin among women with triple-negative breast cancer, researchers conducted a Phase III clinical trial known as BEATRICE. The study enrolled 2,591 women with operable cancer. After surgery, women were treated with four or more cycles of chemotherapy with or without one year of Avastin.
Study participants have been followed for 32 months.
- Invasive disease-free survival (survival with no recurrence of invasive breast cancer and no new invasive breast cancer) was slightly better among women who received Avastin, but this result did not meet the criteria for statistical significance, suggesting that it could have occurred by chance alone.
- Information about overall survival is not yet available, but is expected in 2013.
- Serious side effects that were more common among women treated with Avastin included high-blood pressure and heart problems.
These results suggest that the addition of Avastin to adjuvant chemotherapy does not improve disease-free survival among women with triple-negative breast cancer. Study participants continue to be followed in order to assess the effect of Avastin on overall survival.