WebMD Health News
Louise Chang, MD
Jan. 10, 2007 -- Drugs that target blood vessels that feed tumors are
showing promise in the treatment of advanced kidney cancer.
Two studies published in the latest issue of The New England Journal of
Medicine represent a "major step forward" in kidney cancer
treatment, a leading researcher in the field tells WebMD.
The studies offer some of the best evidence yet that therapies that target
the tumor blood supply -- known as antiangiogenesis drugs -- have a role to
play in cancer treatment, says James Brugarolas, MD, PhD, of the University of
Texas Southwestern Medical Center in Dallas.
Researchers evaluated the oral drugs sunitinib and sorafenib. The drugs
target the blood supply of the tumor and tumor growth.
"Just a few years ago, we only had one highly toxic drug approved for
the treatment of this cancer," says Brugarolas, who did not participate in
the two trials. "We now have these new treatments that arise from our
understanding of the biology of this cancer."
The two new drugs did not cure patients of their disease, and it is not yet
clear if they help keep patients alive longer than traditional drug
But both drugs appeared to slow tumor growth by several months in patients
who participated in the two studies.
An estimated 39,000 Americans are diagnosed with kidney cancer each year,
and 13,000 people die of the disease, according to the American Cancer
Surgery is the treatment of choice for localized disease, but in well over
half of cases the tumor has either spread beyond the kidneys at diagnosis or
the cancer recurs following surgery.
For many years, the toxic therapies interferon alfa or interleukin-2 have
been the only available treatments for advanced renal kidney cancer, but they
work for only a small percentage of patients.
As a result, the estimated five-year survival rate for patients with
advanced kidney cancer is less than 10%, according to the National Cancer
These drugs help prevent tumor growth and target the tumor's blood supply.
Both sunitinib and sorafenib have been approved by the FDA for the treatment of
advanced kidney cancer.
The brand name of sunitinib is Sutent; it's made by Pfizer. The brand name
of sorafenib is Nexavar; it's made by Bayer Healthcare. Both are WebMD
The newly reported sunitinib trial included 750 previously untreated
patients with advanced kidney cancer. About half of the
patients were treated with a standard course of the oral drug and about half
received a standard course of interferon alfa.
Researchers reported that the median time it took tumors to grow, known as
disease-free progression, was more than twice as long in the sunitinib-treated
patients than in those treated with interferon -- 11 months vs. five
And 31% of the patients on the newer drug had improvements from treatment --
as seen on radiologic imaging -- compared with just 6% of the
interferon-treated patients. As a group, the sunitinib patients also reported
significantly better overall quality of life than the patients treated with
Researcher Robert J. Motzer, MD, of New York's Memorial Sloan-Kettering
Cancer Center, tells WebMD that it is still not clear if treatment with
sunitinib keeps patients alive longer, but he adds that there is good reason to
believe that it does.
"You would expect that more than a doubling in disease-free survival
would translate into longer overall survival, but we can't say that yet,"
Unlike the patients in Motzer's trial, those in the sorafenib study had
already been treated, mostly with either interferon alfa or interleukin-2. All
were considered treatment resistant.
Half of the 903 study participants received sorafenib and the other half
Compared with placebo-treated patients, patients treated with sorafenib also
had longer median progression-free survival (5.5 months vs. 2.8 months), and a
higher response rate (10% vs. 2%).
There was a greater incidence of toxic side effects in the sorafenib-treated
patients. The most commonly reported toxicities were diarrhea, rash, fatigue, and unpleasant
skin reactions in the hands and feet. Serious adverse events included heart
problems in 12 patients and hypertension.
In the study by Motzer and colleagues, just under a third of patients
reduced their dosage of the antiangiogenesis drug due to these toxicities.
Motzer says the next step for researchers is to determine if responses
improve when sunitinib, sorafenib, and similar therapies are given in
"For many years, kidney cancer has been considered to be among the most
treatment-resistant cancers," he says. "In the past there has been
little hope for success with any treatment, but these drugs are changing
SOURCES: Motzer, R.J. and Escudier, B. The New England
Journal of Medicine, Jan. 11, 2007; vol 356: pp 115-134. Robert J. Motzer,
MD, attending physician, Genitourinary Oncology Service, Memorial
Sloan-Kettering Cancer Center, New York City. James Brugarolas, MD, University
of Texas Southwestern Medical Center, Dallas.
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