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By DANIEL Q. HANEY : AP Medical Editor
Jun 2, 2003 : 4:53 pm ET
CHICAGO -- Shares of two cancer drug makers
soared Monday on news that their experimental treatments were
effective in clinical trials.
ImClone Systems Inc. stock rose more than 17
percent a day after a study presented Sunday at the American Society
of Clinical Oncology, doctors concluded Erbitux, the cancer drug
that enmeshed ImClone Systems in an insider trading scandal, worked
just as well as an earlier company-sponsored study said it did.
Separately researchers released a study of
Genentech's experimental drug Avastin, which showed the drug
modestly lengthened survival -- notable in a field where even
inch-by-inch improvement can be hard to document -- by cutting off a
tumor's blood supply. Genentech shares jumped more than 6 percent in
Monday trading.
Research on treatment targeting a tumor's
blood supply was developed around the idea that cancer needs a
growing network of blood vessels to survive -- a theory championed
by Harvard University's Dr. Judah Folkman. According to the theory,
shutting down the process, called angiogenesis, should arrest tumors
and even obliterate them.
After decades of obscurity, Folkman's theory
became front-page news in 1998 with reports his
angiogenesis-blocking drugs cured mice. Some predicted he was on the
verge of curing human cancer, too.
"This is a landmark announcement," said Dr.
William Li, head of the nonprofit Angiogenesis Foundation. "It's the
first true validation in a well-designed clinical trial that cutting
off a tumor's blood supply can improve cancer survival."
The treatment is an antibody aimed against
vascular endothelial growth factor, or VEGF, one of the more than 20
chemicals that help tumors' blood vessels grow and survive.
The study, directed by Dr. Herbert Hurwitz of
Duke University, involved 925 colon cancer patients who all received
a standard chemotherapy cocktail of irinotecan, 5-fluorouracil and
leucovorin. They were also randomly given either Avastin or a dummy
placebo.
Those on Avastin survived an average of 20
months, compared with nearly 16 months in those getting only
standard treatment. The results were a surprise, since an earlier
study found no benefit of Avastin against breast cancer.
Dr. Mace Rothenberg of Vanderbilt said when
he was in medical school, such patients typically survived just six
months. "This improves median survival by about 30 percent," he
said. "When you put it in those terms, it is very meaningful to
patients."
In another major cancer study, this one
involving ImClone's drug Erbitux, questions that led to the Food and
Drug Administration's December 2001 rejection of the drug's approval
appear to have been answered.
Erbitux is one of a new class of cancer
medicines designed to work with pinpoint accuracy against the
molecule-level defects that make the disease flourish. It is an
antibody that jams up cancer's complex interplay of chemical growth
signals.
In ImClone's initial study, Erbitux was
tested on people with advanced colon cancer who had already failed
to respond to irinotecan. Researchers believed Erbitux could restore
some of the chemotherapy's punch.
Usually, studies are designed to test an
experimental drug against the standard medicines. But in this case,
doctors reasoned since the patients had already failed on irinotecan
alone, any improvement with the combination could be attributed to
Erbitux, so no comparison group was needed.
While the data showed nearly a quarter of
patients responded to the combination, the FDA turned back ImClone's
application for approval, saying Erbitux alone might have worked
just as well. It also questioned whether all the patients had truly
failed on chemotherapy.
The new study was conducted on 329 colon
cancer patients who had clearly failed to respond to irinotecan,
based on strict definitions. They were given either Erbitux alone or
in combination with irinotecan.
It found 23 percent getting the combination
and 11 percent taking Erbitux alone responded to treatment, meaning
their tumors shrank by at least half. However, the effect was
typically brief. Median survival was nearly nine months for those on
the combination and seven months for patients getting only Erbitux.
Doctors who led the latest study said they
felt frustrated U.S. cancer patients may have been denied a drug for
years that could have helped them.
"We had desperate e-mail form patients who
wanted to move to Europe to receive the drug. It was a great loss
for cancer patients," said Dr. David Cunningham of Royal Marsden
Hospital in England, who directed the new study and presented the
findings Sunday.
Despite doubts by other cancer specialists,
Dr. Robert Mayer, head of gastrointestinal cancer at Boston's
Dana-Farber Cancer Institute, who was not involved in the study,
contended the study demonstrates beyond doubt that Erbitux can fight
cancer.
"For those who were skeptical about Erbitux,
perhaps influenced by all the financial shenanigans, this clearly
shows that the drug is active," he said.
ImClone's former chief executive, Dr. Samuel
Waksal, pleaded guilty to securities fraud and other charges and
will be sentenced June 10. He tried to sell 80,000 shares of company
stock and advised his daughter to unload her holdings before news of
the FDA's unfavorable decision became public. His friend, the home
design celebrity Martha Stewart, is under investigation for her own
sale of nearly 4,000 ImClone shares the day before the FDA
announcement.
Shares of ImClone rose $5.00 to close at
$33.50 on the Nasdaq Stock Market, adding to a 21 percent gain
Friday on published reports of good results.
Genentech shares gained $4.12 to close at
$66.73 on the New York Stock Exchange. Genentech shares have surged
82 percent since the company surprised the industry and the market
May 19 by reporting that Avastin, which previously had been written
off as a failure in treating breast cancer dramatically extended the
lives of some of the sickest colon cancer patients.
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EDITOR'S NOTE: Medical Editor Daniel Q. Haney
is a special correspondent for The Associated Press.
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Conference site:
http://www.asco.org
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