LAST year the Food and Drug Administration rescinded approval of the drug Avastin for treating breast cancer patients, prompting a firestorm of criticism. The decision was denounced by some politicians as health care rationing, and by breast cancer patients who feared that they would be deprived of a drug that they felt had helped them immensely.
But these criticisms ignore the facts: Avastin was rejected simply because it didn’t work as it was supposed to, and the F.D.A. should resist the aggressive campaign by Genentech, the drug’s maker, to get that ruling reconsidered at a hearing in late June.
Avastin has been on the market for seven years, and combined with other drugs it is effective in treating, but not curing, some colon, lung, kidney and brain cancers. It inhibits the development of new blood vessels and in so doing can starve a growing tumor.
Treating a breast cancer patient with Avastin costs about $90,000 a year, and Genentech could lose $500 million to $1 billion a year in revenue if the F.D.A. upholds the ban.
A clinical trial published in 2007 demonstrated that Avastin, when paired with the chemotherapy drug Taxol, halts the growth of metastatic breast cancer for about six months longer than chemotherapy alone. Genentech then asked the F.D.A. for approval of Avastin, combined with Taxol, for use against metastatic breast cancer.
This halt in tumor growth is known as progression-free survival. But delaying the worsening of cancer does not necessarily prolong life, and Avastin was not shown to lengthen patients’ overall survival time. So Genentech argued that the drug led not to longer life, but to improved quality of life.
In 2007, an F.D.A. advisory committee rejected the application, deciding that the toxic side effects of Avastin outweighed its ability to slow tumor growth. The F.D.A., however, overrode the committee and granted what is called accelerated approval, allowing Avastin to be used pending further study. The criteria for full approval was that Avastin not worsen overall survival and that the drug provide clinically meaningful progression-free survival.
To support its case Genentech submitted data from two additional clinical trials in which Avastin was paired with chemotherapy drugs other than Taxol. Like the first trial, neither showed a survival benefit. Both showed an improvement in progression-free survival, though this outcome was much less impressive than in the original study. In addition to seeking full approval for the Avastin-Taxol combination, Genentech also asked the F.D.A. to approve the use of Avastin with the drugs used in these follow-up studies.
Genentech presented progression-free survival as a surrogate for better quality of life, but the quality-of-life data were incomplete, sketchy and, in some cases, non-existent. The best that one Genentech spokesman could say was that “health-related quality of life was not worsened when Avastin was added.” Patients didn’t live longer, and they didn’t live better.
It was this lack of demonstrated clinical benefit, combined with the potentially severe side effects of the drug, that led the F.D.A. last year to reject the use of Avastin with Taxol or with the other chemotherapies for breast cancer.
In its appeal Genentech is changing its interpretation of its own data to pursue the case. Last year Genentech argued that the decrease in progression-free survival in its supplementary studies was not due to the pairing of Avastin with drugs other than Taxol. This year, however, in its brief supporting the appeal, Genentech argues that the degree of benefit may indeed vary with “the particular chemotherapy used with Avastin.” In other words, different chemotherapies suddenly do yield different results, with Taxol being superior. The same data now generate the opposite conclusion.
Perhaps more troubling is the resort to anecdote in the brief to the F.D.A. and in the news media. Oncologists recounted their successes, and patients who were doing well on Avastin argued for its continued approval. But anecdote is not science. Such testimonials may represent the human voices behind the statistics, but the sad fact is that there are too many patients who have been treated with Avastin but are not here to tell their stories.
Avastin will not disappear because of the F.D.A. decision. It remains available for treating other cancers, and research to find its appropriate role in breast cancer treatment continues. In the meantime, the F.D.A., which is expected to make its decision in September, needs to resist Genentech’s attempt to have it ignore scientific evidence.
Serious progress in the treatment of cancer will not be the result of polemics, lobbying or marketing. Genentech’s money and efforts would be better spent on research for more meaningful treatments for breast cancer.
Thursday, June 02, 2011
Drugs and Profits - NYTimes.com
via nytimes.com
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