Sutent, or sunitinib malate - gastrointestinal stromal

http://www.usatoday.com/news/health/2005-11-03-intestinaldrug_x.htm
Posted 11/3/2005 1:01 PM
Study shows new drug delays intestinal cancer
PARIS (AP) ? A new drug has been shown to dramatically delay the
progression of a rare type of intestinal cancer in patients who have run
out of options because their tumors have outsmarted even the latest
high-tech drug.

Sutent belongs to a new class of cancer drugs that target multiple tumor
activities at once. Doctors are hopeful it will usher in a new era of
combinations of finely targeted drugs that can greatly improve the
prognosis of cancer patients ? in much the same way that
triple-combination therapy has revolutionized HIV treatment.

Conventional chemotherapy drugs kill cancer cells, but they also damage
healthy tissue. The newer generation of drugs specifically target tumor
cells and leave the rest of the body alone. However, they hone in on a
single tumor function, don't work for everybody and can stop working after
a while.

Sutent, or sunitinib malate, seems to shrink tumors by simultaneously
starving them of blood, blocking signals that tell them to grow and
spread, and causing cancer cells to die. It is being tested in patients
for whom the latest targeted drugs have failed and has shown promise in
previous studies in kidney and breast cancer patients. It is one of more
than 10 multitasking drugs being studied in various types of cancer.

The research, presented Thursday at the European Cancer Conference in
Paris, studied Sutent in 312 people in Europe, the United States,
Australia and Asia with a type of cancer called gastrointestinal stromal
tumor, or GIST.

The prognosis of this cancer had been dire until the targeted drug
Gleevec, or imatinib, came along about five years ago. However, Gleevec
stops working for most patients within two years as the tumor develops
resistance to it.

In the study, two-thirds of patients, who had all developed resistance to
Gleevec, got the new drug, while one-third received a fake treatment.

Sutent delayed the time to progression of the tumor from 6.4 weeks to 27.3
weeks, the study found. It is too early to tell whether the treatment is
saving lives.

The study was paid for by Sutent's developer, Pfizer.

The findings are good news for GIST patients, said Dr. Gordon McVie of the
European Institute of Oncology in Milan, Italy, who was not connected with
the research.

"There was a fear when imatinib was so successful that when resistance
occurred, that was going to be it," said McVie. "What's really exciting is
that behind Gleevec came two more buses ? this one, and a second drug.
These drugs have lifted everybody's expectations all over again."

But experts agree the promise of Sutent and other such drugs goes beyond
GIST, which is being used as a proving ground for other cancers because
scientists understand its simple circuitry.

"It has huge scientific implications, that's for sure," said Dr. Jose
Baselga, an oncologist at the Valla d'Hebron Hospital in Barcelona, Spain,
who was not tied to the research.

The study's leader, Dr. George Demetri, associate professor of medicine at
the Dana Farber Cancer Institute in Boston, said the findings will help
scientists think more creatively about more complicated cancers.

"We are trying to put together the rule book on cancer," he said.

The experience with HIV therapy, where huge leaps in survival were seen
after triple combination cocktails came along, has provided good lessons
for cancer, Demetri said. Testing of Sutent in combination with other
drugs is already underway, he said.

"The cells probably have a rather limited repertoire of tricks they can
fall back on. If you put pressure on one pathway, the cell finds a
different pathway to squeeze around. But if you block that pathway too,
the cell is stuck. They get trapped, they can't grow and they die,"
Demetri said. "That's the theory."

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