FDA Approves Cancer Fighting Drug Posted Friday, February 27, 2004 by ctustis
Colon Cancer Treatment Not a Cure, Agency Warns
Associated Press
Thursday, February 26, 2004; 6:34 PM

The first drug that promises to attack cancer by choking off its blood
supply won federal approval Thursday, a treatment for advanced colon
cancer called Avastin.

It's not a cure, cautioned the Food and Drug Administration: Avastin can
extend patients' lives by a median of five months, meaning half do
better and half worse.

But it's a significant development. Few other drugs for advanced stages
of this cancer have provided even that much benefit.

Also important, Avastin becomes the first drug proved to work according
to a novel theory that tumors must form a network of blood vessels to
survive -- a process called angiogenesis -- and that shutting down that
process could fight cancer in a completely new way.

Avastin's approval marks "a milestone in a new form of cancer therapy,"
said Dr. Judah Folkman of the Harvard-affiliated Children's Hospital of
Boston, who pioneered the anti-angiogenesis theory 30 years ago.

Manufacturer Genentech Inc. "is to be congratulated for elegant
scientific work that has converted a theory into a therapy," Folkman said.

It was a long, hard road. Folkman made front-page news in 1998 with
reports that his anti-angiogenesis drugs had cured mice of cancer. But
early attempts to make such drugs work in people kept failing.

That may be because doctors initially tested them in the most difficult
of patients, those who had failed numerous chemotherapies, said Dr.
Louis Fehrenbeacher, head of Kaiser Permanente's cancer study program
who helped test Avastin. Tumors that survive repeated treatment seem to
be the hardiest, and anti-angiogenesis will do its best work earlier in
the disease, he said.

Indeed, Avastin is approved as a first-line treatment for metastatic
colon cancer, where the cancer has just spread throughout the body.

In a study of 800 people, half received intravenous Avastin in addition
to routine chemotherapy every two weeks. Not only was tumor growth
delayed in the Avastin patients, but they lived a median of 20 months,
five months longer than those getting standard treatment.

That's a 30 percent increase in survival, which is very exciting, said
FDA Commissioner Mark McClellan.

Some patients did better. Fehrenbeacher points to some of his who have
lived almost three years.

Avastin is a monoclonal antibody, a substance that seeks out and binds
to one of the more than 20 chemicals known to help tumors' blood vessels
grow. The one Avastin targets is called vascular endothelial growth
factor, or VEGF. When Avastin binds to it, VEGF can't stimulate blood
vessel growth, thus keeping tumors from growing by denying them
nourishing blood.

Genentech said it will begin shipping Avastin in three days. The
wholesale cost will be $4,400 per month; in the study, most patients
underwent 10 months of Avastin therapy.

FDA's decision marks the second new treatment approved for advanced
colorectal cancer in as many weeks. Erbitux, the drug at the center of
the stock-trading scandal that brought Martha Stewart to trial, works in
a different way, by blocking growth of the colon tumor itself, not its
blood supply. FDA is allowing it to sell based on studies proving tumor
shrinkage; no one yet knows whether Erbitux will actually help patients
live longer.

Scientists are working to see if Avastin can treat other cancers, too.
It failed as a last-ditch breast cancer treatment, but studies are under
way to see if it helps in earlier stages of that disease and lung
cancer, Fehrenbeacher said.

In all, 30 anti-angiogenesis drugs now are being tested in people around
the world, Folkman said -- including one he developed, called
endostatin, that is showing promising results in a handful of patients
with some rare cancers.

As for Avastin, the FDA cautioned that it occasionally causes some
serious side effects including holes in the colon, impaired wound
healing and internal bleeding.

More common side effects are high blood pressure, fatigue, blood clots,
diarrhea, appetite loss and increased risk of infection because of
decreased white blood cells.

In trading on the New York Stock Exchange, Genentech shares closed at
$103.10, up $7.02, or 7.3 percent.