The news this afternoon that an FDA advisory panel recommended removing approval for bevacizumab (Avastin®) as a treatment for advanced breast cancer is certainly going to be difficult for patients, their families, supporters and doctors alike.
The unfortunate reality is that despite earlier reports that this targeted therapy (which has been successful in treating a number of other cancers and works by inhibiting the growth of new blood vessels that feed cancer tumors) was successful in treating advanced breast cancer didn't hold up when studied in further clinical trials.
Bevacizumab in the treatment of breast cancer has followed a long, somewhat tortuous course beginning as early as 2005 with an announcement by the National Cancer Institute that the drug was successful in a clinical trial where women with advanced breast cancer were treated with the drug.
Following that announcement, it took an additional almost 3 years until the FDA approved bevacizumab as a treatment for breast cancer. However, that approval was not a "slam dunk", after another FDA advisory panel had recommended against approval on a close vote. The FDA overrode the panel's recommendation, and gave the drug a conditional approval while further clinical trials were underway.
It was the results of those clinical trials that were presented to the FDA's cancer drug advisory panel today, resulting in an overwhelming (12-1) vote to remove approval of bevacizumab as an effective treatment for advanced breast cancer.
The trials in question used standard chemotherapy with or without bevacizumab, and looked to see how long the treatment(s) delayed the progression of breast cancer (what we call "progression free survival", or PFS) as well as how long the women lived after they received their treatment ("overall survival" or OS).
The reports from a couple of years ago showed the addition of bevacizumab almost doubled progression free survival from 5.8 months to 11.3 months. However, the data at that time did not show that bevacizumab increased survival, which up to this point in time has been the "gold standard" for approving almost all cancer treatment drugs. That is one of the reasons the FDA asked for more information.
For some of us, the core question at that time was whether or not women had a better quality of life during that period of extended progression free survival, even if the drug did not increase the length of their days. The thinking was that even if total survival wasn't improved, at least if they had better function and less pain, it would still be worthy to consider the drug effective. Unfortunately, the studies were not designed to give an answer to that question.
Now come the two new studies, and the news wasn't particularly impressive that bevacizumab made a real difference in the treatment of the women in the trials.