The FDA’s Decision to Remove Approval for Avastin in Metastatic Breast Cancer is Caught Between Data and Emotion

I attended a hearing today held by the Food and Drug Administration outside of Washington DC on the question of whether or not Avastin® (bevacizumab) should retain approval for the treatment of metastatic breast cancer. As one might expect, the experience ran the gamut from deeply felt emotions to cold hard statistics.

The presentations by patients and physicians for the most part opposed the FDA decision to remove the breast cancer indication, while an occasional person supported the FDA based on their interpretation of the data. For the patients and their supporters, it was the reality that many of them were alive and well with few symptoms, which they and their physicians attributed to the fact that Avastin® had a significant treatment benefit for their breast cancer.

But the FDA told a different story.

The data from clinical trials, after looking at thousands of patients treated with Avastin® in addition to more standard chemotherapy showed no meaningful clinical benefit. At one point, an FDA representative said that they were looking for only one trial that had some sort of benefit, whether improved performance free survival, overall survival, or quality of life. But in their review, no such trial emerged while the side effect risk was considerable. And, as they pointed out at the end of the day, there are many other treatment options available for women with metastatic breast cancer, without significant, substantial evidence that Avastin® fills an unmet need in the treatment of these women.

As to the patients who testified from their hearts earlier in the day that they have been saved by Avastin®, one advisory committee member said that they have ignored the fact that they also received standard chemotherapy in addition to Avastin®, and that oncologists have always seen patients treated with more standard drugs that have had similar responses. In the words of the committee member who made that comment, doctors who lead patients to believe that their treatment success is due to Avastin® are doing their patients a disservice. In none of the clinical trials did a group emerge that responded so well to Avastin® as to make them special responders, and where the success of their treatment could be attributed to Avastin® alone.

Tomorrow brings counter testimony from Genentech, the maker of Avastin®. If similar to the “cross examination” we heard earlier today, we can expect Genentech to focus on what constitutes success in a clinical trial, and how we should not ignore the obvious responses to the drug. For Genentech today, it was much about hazard ratios and median duration of responses, while the FDA focused on the totality of the data and “clinically meaningful responses”, a term that does not lend itself easily to uniform definition.

Clearly, we are in a place where emotion meets science and the FDA’s decision will prove to be a difficult one. Ultimately, we hope the FDA will make the best decision possible based on the science–flawed that it might be–and in consideration of the public interest and our deep felt concern for the welfare and treatment options for women with metastatic breast cancer.

PS: If you are interested in what happened throughout the day at the FDA hearing, check out my tweets @drlen.