On Friday, the FDA announced its decision to revoke Avastin's labeling indication for metastatic breast cancer, granted through the agency's accelerated approval (AA) program. The FDA and the Obama Administration are bound to take some heat for this one (as a prelude to Obamacare rationing) but this is one case where I think the FDA did the right thing by following its own rules for AA.

I wouldn't hesitate to criticize the decision if I thought otherwise. A few quick points:

First, the FDA's decision is a lagging indicator. After the most recent studies on Avastin's use in metastatic breast cancer came out, use of the drug plummeted as oncologists interpreted the data and decided that it wasn't working as well for patients as early data had suggested it would. The market, in other words, is working to incorporate information faster than the FDA. That's a good argument for shifting the agency to being more of an information conveyer than a pre-market gatekeeper.

Second, Avastin isn't going to be withdrawn from the market. Doctors can still use it off-label, as they always could, to treat metastatic breast cancer - and they can make that decision on a case by case basis. Medicare is still covering Avastin treatment for breast cancer, and the National Comprehensive Cancer Network still lists Avastin for use in metastatic breast cancer. (The NCCN affirmed this decision in July.) Private insurers like UnitedHealth, that follow the NCCN, will likely continue to pay for Avastin. Some insurers may stop covering Avastin, but this is a market decision, not the FDA's decision. Don't shoot the messenger.

Third, if you think (as I do) that the FDA should be expanding the accelerated approval pathway and allow more drugs to get to market based on promising early studies. rather than waiting for large Phase III clinical trials that can take years to complete, you can argue that this outcome actually strengthens AA. Critics have charged that AA is sop to industry, and that companies never do the follow up studies to support AA. Avastin proves them wrong.

Finally, this is far from the end of the story. Experts agree that some patients with metastatic breast cancer do very well on Avastin, but no one knows how to identify those patients ahead of time. Roche has already announced that's conducting a Phase III trial looking at a potential biomarker for identifying the patients who are likely to get the most benefit from Avastin.

That's exactly where cancer treatment is going: biomarker driven treatments that are given to the patients who are likely to get the most benefit and the fewest side effects (like Herceptin, a targeted breast cancer drug).

In the future, broad labels like "metastatic breast cancer" will mean less and less as drugs are built from the ground up to attack the molecular mechanisms of cancer. Avastin's use will undoubtedly be further refined and improved through the same process. The FDA's decision today won't stop that, and it might even help accelerate it.

For more background, here's a link to the New York Times article on Avastin, and to Commissioner Hamburg's 70 page memo explaining the agency's decision. You can find the report here.