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| New Breast Cancer Drug – Questionable Benefit |
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You may have heard that in February the FDA approved a new drug for breast cancer: Avastin, which is the commercial name for bevacizumab. You may have also heard that there is controversy over this approval. What is Avastin and what is the controversy? This is one of several drugs in clinical trials looking at whether stopping the formation of new blood vessels in a tumor will “starve” the tumor and hopefully thus hinder its spread. The idea of hindering tumor blood flow has been around for years and despite spectacular cures in mice, results in people are unclear and appear to be quite modest. Breaking with its guidelines and past approvals, the FDA approved this drug in the first line metastatic setting based on progression free survival and not overall survival. What does that mean? The patients who received Avastin had the same survival as the patients who received standard of care therapy. The difference was that the Avastin patients had a longer time in which their tumor did not progress. There was no difference in quality of life, but there were significant side effects in the Avastin arm and also treatment related deaths in the Avastin arm, none in the control arm. Our full position against approval can be found in our letter to the FDA (link). There was no reason we could not wait for the longer-term results of this trial and the results of other ongoing trials looking at Avastin in first line metastatic disease. There was no public health or patient imperative that required approval at this time, on such limited benefit. And the cost of the drug will be huge: $55,000 to $100,000 a year. The idea of starving the blood supply of a tumor is exciting and we all want this to work. It may still have major impact, in a subgroup of breast cancer we have not yet identified. But because of this approval, the drug will be tested in adjuvant breast cancer patients: even though no survival benefit was shown and even though the toxicities are severe and there were deaths in the Avastin arm, yet none in the standard therapy arm. We must rethink what we expect from drugs and whether pushing more and more drugs into the marketplace is really what’s best for patients. |