Doctors Debate FDA Move, Which May Have Big Implications for Cancer Drug Approvals

FDA Gives Conditional OK to Avastin for Breast Cancer

Doctors Debate FDA Move, Which May Have Big Implications for Cancer
Drug Approvals
By AUDREY GRAYSON
ABC News Medical Unit
Feb. 22, 2008--


The U.S. Food and Drug Administration Friday afternoon granted a
conditional approval for Avastin to treat breast cancer patients --
despite a recommendation by an FDA expert advisory panel in December
to reject the new use.

The FDA has traditionally approved drugs for late-stage cancer only if
they extended or improved the quality of patients' lives. In this
case, the agency's decision to approve Avastin was based on the drug's
tumor-shrinking abilities.

Some experts say the basis of this decision has huge implications for
the future of breast cancer drug treatments.

"The FDA's approval process for Avastin tells us that regulators are
now making quality-of-life issues an important part of their decision-
making," said Dr. Len Lichtenfeld, deputy chief medical officer of the
American Cancer Society.

Avastin, a drug already approved for the treatment of colon and lung
cancer, was OK'd for treatment of advanced breast cancer under the
FDA's accelerated approval program, which allows the agency to green
light products for cancer or other life-threatening diseases based on
initial positive clinical data.

Full approval of the drug is pending on the FDA's complete review of
three additional randomized trials on Avastin, which have been
submitted by Genentech.


Lack of Proof?
Going by the current research available on Avastin, some cancer
experts contend that there is simply not enough data in support of the
drug to warrant full FDA approval.

"I would have voted against approval," said Dr. Anthony Elias,
director of the Breast Cancer Research Program at the University of
Colorado Health Sciences Center. "One trial that is negative [on
Avastin] and one trial [that is] positive does not give a clear
answer."

The study that Genentech, Avastin's manufacturer, submitted to the FDA
found that using Avastin in combination with Taxol, a breast-cancer
drug made by Bristol-Myers Squibb Corp., delayed the growth of
patients' tumors for 11.3 months -- 5.5 months longer than Taxol
alone.

But despite this, the study found that the women on Avastin didn't
live significantly longer than those on Taxol, and they experienced
more adverse side effects, such as high blood pressure, blood clots
and bowel perforation. Moreover, six deaths were linked to Avastin's
toxicity.


A Last Hope for Some
While the drug has not yet been proved to extend the lives of women
battling breast cancer, some experts say the approval of Avastin is
justified solely on the basis that it could improve the quality of
life of those with the disease.

In that respect, Avastin would not be the first drug whose approval
was pegged to the possibility that it could lead to an easier life for
cancer patients, rather than a longer one. Last March, the FDA decided
to approve another breast cancer drug, called Tykerb, for similar
reasons.

"As we move forward with targeted therapies, we're going to run into
this situation more and more frequently," Lichtenfeld said. "So if we
start thinking in terms of converting cancer from a fatal disease to a
chronic disease ... drugs that improve quality of life will become
more important."

Breast cancer is a curable disease, but once it has metastasized it is
considered treatable but not curable. The American Cancer Society
estimates that 40,000 women die of metastatic breast cancer each year.
Of those, Genentech estimates that 38,000 have tumors that might
respond to Avastin.

"Athough metastatic breast cancer remains incurable despite drugs like
Herceptin, Avastin and others, it is eminently treatable," said Dr.
Joseph Sparano, associate chairman of the department of oncology at
the Montefiore Medical Center in New York. "In my view, a drug that
doubles the chance of controlling the disease but doesn't affect
survival is just as useful as one that prolongs survival by a few
months."

Genentech estimates that 75 percent of women found to have breast
cancer that has already spread have tumors that are HER2-negative --
and thus may be helped by Avastin.

Avastin works by replicating the body's own weapons -- antibodies that
block the growth of blood vessels that feed tumors.

Breast cancer is the second most common form of cancer and the second
leading cancer killer among American women. According to the American
Cancer Society, an estimated 178,000 women in the United states were
diagnosed with breast cancer in 2007.


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