The FDA has removed Avastin’s approval for the treatment of metastatic breast cancer. This decision was based on data from large clinical trials that showed Avastin neither delayed cancer growth nor improved survival in breast cancer patients when compared to standard chemotherapy. Furthermore, treatment with Avastin exposes patients to serious side effects including high blood pressure, hemorrhaging, and blood clots. Avastin’s approval ordeal has been a difficult and controversial issue for breast cancer patients, some of who feel that the powerful antiangiogenic drug has contributed to the success of their treatment.
So, why was Avastin approved in the first place for the treatment of breast cancer? Excitement about Avastin’s performance in the treatment of other cancers (for which it was already approved) prompted the FDA to push Avastin through its accelerated approval program. The accelerated approval program exists to provide earlier patient access to a potentially exciting drug while clinical trials are ongoing to confirm the drug’s effectiveness. The downside of the accelerated approval process, however, is that a drug can be approved based on data that are incomplete and thus insufficient for full approval. Unfortunately, in larger breast cancer trials, Avastin did not provide the benefit required to justify its use.
Avastin is still approved for treating non-small cell lung cancer (NSCLC), colorectal, brain and kidney cancer and these patients can continue to take Avastin in good faith. For these cancers, unlike for breast cancer, evidence collected from large studies over long periods of time has shown that Avastin therapy delays the growth and spread of cancer and prolongs survival. These benefits outweigh the risks associated with the drug.
As for breast cancer patients – the story may not be over just yet. Doctors can still approve Avastin for breast cancer patients “off-label” (though many insurance companies – Medicare notably excepted – will be less likely to pay for a drug that is no longer approved). But personally, what I find most encouraging is this: as we march forward in this age of personalized medicine, doctors and scientists will continue the search for molecular markers that may identify a subgroup of patients who are likely to derive significant benefit from a drug such as Avastin. Tried again in a selected group of breast cancer patients, Avastin just might prevail.