Bevacizumab (Avastin) for Breast Cancer, Expensive and Mediocre

Todays NY Times reports that Genentech will try to pressure the FDA to continue the bevacizumab (Avastin) indication for treatment of breast cancer.

It should be stated up front that the drug can be used for breast cancer without FDA approval. The question is whether medicare and other insurers should should be forced (by virtue of the FDA approving the indication) to cover a wildly expensive ineffective treatment.

The data on this drug’s lack of efficacy is clear. It was originally approved in a study which showed a delay in progression of disease. At the time of approval, little was known whether patients so treated would actually live longer. Genentech wanted accelerated approval and agreed that followup studies would be done to confirm its efficacy, not only in delaying progression but also in improving survival.

The F.D.A. approved the drug for advanced breast cancer in February 2008, after one clinical trial showed that combining Avastin with another drug, paclitaxel, delayed the median time before tumors worsened by 5.5 months, compared with using paclitaxel alone. But the women who got Avastin did not live significantly longer than those who got only paclitaxel, which is also known by the brand name Taxol.

and:

Subsequent trials, in which Avastin was combined with different chemotherapy drugs, showed a much smaller delay in tumor progression, ranging from less than 1 month to 2.9 months. And again there was no improvement in survival for those receiving Avastin.

Yet another trial showing this drug’s huge costs and limited efficacy was reported on at ASCO 2011, we commented on this trial here. The study reported .49 years delay of progression free survival and just .135 years (about 1.5 months) of life extension–a cost of $745,000 for a QALY (quality adjust life year). Hardly evidence of a cost-effective intervention, or for that matter a drug that works.

This controversy is in part due to the erosion of standards in clinical trials. At one time patients were deemed to show a response if the tumor decreased in size by 50%. The gold standard for an effective treatment was an improvement in survival, not a mere delay in progression.

It turns out unfortunately that a delay in progression often means little in regard to survival and in the case of bevacizumab (Avastin) even that delay is open to question as repeated studies show a more limited delayed progression as well the lack of a significant survival benefit.

Medicynical Note: With drugs as expensive and ineffective as this one is in breast cancer, it’s easy to understand why health care costs are out of control.


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