The FDA's announced intention to revoke Avastin's approval as treatment for late-stage breast cancer continues to inflame debate, with most commentary I've seen resoundingly against the government's plans. Here, a patient advocate provides some insight on the FDA's flawed process for fast-track approval of drugs. Give it a read and tell us your thoughts in the comment section below. — Nicole Brochu

By Robert Goldberg

At a time when the approval of new cancer drugs is declining, why is the FDA making it even harder to keep existing treatments on the market? When the FDA in December announced plans to revoke Avastin's designation as a breast cancer treatment, many Americans received their first exposure to the FDA's dysfunctional fast-track approval program. And it's clear the FDA decision and others like it are partly to blame for the fact that less than 5 percent of all cancer drugs in development make it to patients.

Since it was approved for treating advanced breast cancer in 2008, Avastin has helped improve the quality of life for many women suffering from the disease. By working with chemotherapy drug Taxol, Avastin can slow the growth of tumors — or even shrink them in certain patients.

Now the FDA has changed its mind about Avastin after a subsequent study — one required under the fast-track approval program — suggested it did not sufficiently prolong the average life expectancy of breast cancer patients. But extending average lifespan was not why Avastin was approved in the first place. Sometime between approving the drug and evaluating the follow-up study, the FDA moved the goalposts.

Such follow-up studies are both the heart and the Achilles heel of the fast-track approval program. In exchange for speedy approval of lifesaving cancer drugs, pharmaceutical companies must promise to conduct follow-up studies proving that the drugs can get the job done. Unfortunately, those studies have proven difficult to complete, with some taking more than six years, according to the FDA. Even when the studies are completed, the drug makers' only reward is sometimes the revocation of its approved status.

Why do these follow-up studies pose such a challenge for drug manufacturers? The FDA was wondering the same thing and grilled representatives from GlaxoSmithKline, Eli Lilly and Amgen about the delays at a February advisory committee meeting.

The drug companies offered a range of defenses. For drugs approved for rare forms of cancer, like GlaxoSmithKline's Bexxar, it can be tough to find enough patients to generate reliable results. Other trials can't go forward because by the time drug makers get around to doing them, the protocols have grown outdated — a point the FDA conceded.

The FDA is now making a show of how seriously it takes these studies. "These confirmatory trials are as important — if not more important — than the initial trials leading to the accelerated approval," FDA cancer chief Richard Pazdur told the assembled companies. But if the agency really wants to see them completed, it should support real-world studies to identify which patients respond best to specific drugs. And a good place to start would be to encourage the development of new medications with that focus.

As it stands now, the FDA's hurdles for cancer drugs are increasing. Avastin was approved for late-stage breast cancer more than two years ago because of its effects on tumor growth, which helped many patients live longer and more comfortably. But the new standard that the FDA used to evaluate the follow-up study last summer is called "overall median survival," which measures how long the average patient lives because of the drug.

Unfortunately, Avastin doesn't fare well under that standard because the bulk of its benefit falls on a key set of "super responders" who live significantly longer. For the average patient, however, Avastin only improves the quality of life rather than significantly extends it.

This would not be the first time a fast-tracked drug has been stripped of its designation because of a follow-up study. When AstraZeneca turned in follow-up data on lung cancer drug Iressa in 2005, the FDA pulled that approval as well, though the drug has gained new life from genetic screening. Four other drugs have met a similar fate. If the FDA allowed companies to keep drugs on the market while studying them — as they do with HIV drugs — everyone would have learned more faster.

Genentech is appealing the FDA's decision on Avastin, and concerned breast cancer patients have asked Congress to intervene. Many believe that the FDA was influenced by Avastin's high cost, even though the agency is only supposed to consider safety and efficacy. If the ruling is allowed to stand, a good drug will once again fall victim to bad policy, and countless women could miss out on months or even years of life gained from taking Avastin.

Drugs are granted fast-track approval to further study. If the FDA wants to see those studies completed quickly and competently, it needs to stop skewing the outcomes by changing the rules of research. Such behavior contributes to a decline in new cancer drugs being approved. We must reverse course. Correcting the Avastin decision is a good place to start.

Dr. Robert Goldberg is vice president of the Center for Medicine in the Public Interest. He is also author of "Tabloid Medicine: How the Internet is Being Used To Hijack Medical Science For Fear and Profit" (Kaplan, December 2010).