MONDAY, June 2, 2014 (HealthDay News) -- A pill that blocks male
hormone activity can improve survival and delay the need for
chemotherapy in men with advanced prostate cancer, a new clinical
trial has found.
Men who took a daily dose of the drug enzalutamide started
chemotherapy nearly a year and a half later than men who received a
placebo, even though their prostate cancer had spread to other
parts of their bodies, said senior study author Dr. Tomasz Beer,
deputy director of the Knight Cancer Center at Oregon Health and
"Generally speaking, you don't want chemotherapy. It's very unpleasant. With enzalutamide, we're able to delay the time to chemotherapy by 17 months, which is very significant for patients," Beer said.
The oral drug also improved survival by nearly a third compared
The benefits of enzalutamide were so great that the independent
committee overseeing the clinical trial ended it early so the men
receiving placebo could be offered the drug, Beer said.
Researchers presented the findings Sunday at the American
Society of Clinical Oncology meeting in Chicago. The study was also
published simultaneously online in the
New England Journal of Medicine.
The trial was funded by pharmaceutical companies Medivation and
Prostate cancer is the second leading cancer killer of men in
the United States, behind lung cancer. About one of every seven men
will be diagnosed with prostate cancer in their lifetime, and it
will kill one in every 36 men, according to the American Cancer
Enzalutamide blocks the ability of male hormones, also called
androgens, to bind with prostate cancer cells and fuel their
The drug is already approved by the U.S. Food and Drug
Administration for prostate cancer patients who have had
chemotherapy, based on its ability to prolong their survival, Beer
said. Researchers decided to see if enzalutamide could help men
prior to chemotherapy, since it is an easy-to-take pill with fewer
side effects than standard chemo.
The trial involved more than 1,700 men located across the globe.
Researchers randomly assigned 872 to receive enzalutamide, and the
other 845 to take a placebo.
One year into the study, two-thirds of enzalutamide patients
showed no progression in their prostate cancer, compared with just
14 percent of patients in the placebo group.
Overall, the pill reduced the risk of death by 29 percent,
researchers reported. Seventy-two percent of patients in the
enzalutamide group were alive when the trial was halted. In the
placebo group, 63 percent were alive at the end of the trial.
Men taking enzalutamide generally began chemotherapy more than
two years -- an average of 28 months -- after the start of the
clinical trial. The placebo group started chemotherapy around 10.8
months into the trial.
The medication also caused prostate-specific antigen levels to
decline by at least half in 78 percent of the men assigned
enzalutamide, compared with 3 percent of placebo patients. Doctors
use high PSA levels to diagnose prostate cancer.
Side effects included high blood pressure, fatigue, back pain,
constipation and joint pain.
"It's an incredibly well-tolerated drug that has some minor side effects," said Dr. Bruce Roth, a professor of oncology at Washington University School of Medicine in St. Louis. "Certainly, anything that can delay the onset of chemotherapy is a plus for patients. There are a number of patients where you're just not ready to pull the trigger on something as toxic as chemotherapy, if you can put it off."
Roth added that enzalutamide appears to work just as well as
abiraterone, the only androgen-blocking medication currently
approved by the FDA for use in pre-chemo prostate cancer patients.
Abiraterone inhibits the body's ability to produce androgen.
"It's at least as good as and possibly has a greater magnitude in reduction of risk of death than abiraterone," Roth said.
Both drugs are expensive, costing $8,000 to $9,000 a month, Roth
Roth expects that FDA approval for using enzalutamide prior to
chemotherapy could come fairly quickly. "It's a more streamlined
process to have the label expanded, compared with a new drug
submission," he explained.
U.S. National Cancer Institutefor more on
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