A new hormone
therapy drug for men with prostate
cancer may increase survival a bit and delay progression of the disease in
men who have advanced prostate cancer that has been resistant to standard
hormonal therapies, a new study suggests.
The study found that the drug enzalutamide increased survival by 29% and
delayed disease progression by 81% in men who hadn't received any treatment
"There's new hope for men with very advanced prostate cancer,"
said study author Dr Tomasz Beer, deputy director of the Knight Cancer
Institute at Oregon Health and Science University in Portland. "This is a
treatment with an excellent safety profile that can help men maintain quality
of life and extend disease-free progression and extend survival."
The findings are scheduled to be presented at a meeting of the
American Society of Clinical Oncologists in San Francisco. The study authors
reported receiving research funding from the drug's manufacturers.
Androgen receptor blocker
The US Food and Drug Administration approved enzalutamide in 2012 for use in
men with advanced prostate cancer who have received chemotherapy. The drug is a
type of hormone therapy called an androgen receptor blocker. Androgens are male
Enzalutamide is considered a second-generation hormone therapy.
First-generation hormone therapy drugs for prostate cancer include
bicalutamide, flutamide and nilutamide.
The current study included more than 1 700 men with prostate cancer that had
spread to other areas of their bodies. The men's cancer also had progressed
despite treatment with other types of hormone therapy. None of these men had
yet been treated with chemotherapy. They had, however, been treated with
surgery and radiation
Half of the volunteers were randomly assigned to receive enzalutamide and
the other half received a placebo.
The study was stopped early because it was clear that enzalutamide offered a
benefit over a placebo, so the drug was offered to all of the study volunteers.
"There was an 81% reduction in the risk of disease progression for men
on enzalutamide," Beer said. "The median time to disease progression
in placebo was [about four] months, but on the drug, a median time to disease
progression hasn't been reached despite 20 months of follow-up."
When the study was stopped, 28% of those on enzalutamide had died, compared
with 35% of those taking a placebo. The average median survival rate at the
time of the first analysis was 32.4 months for those on enzalutamide versus
30.2 months for those taking a placebo.
"This drug is being used relatively early in prostate cancer, and
patients can receive multiple treatments after," Beer said of the study
population. Most of the men involved in the study were later treated with
The drug is an oral medication, and it was well tolerated in the study.
Previously published reports from when the drug was first approved suggested
that the wholesale price of the medication would be about $7,450 a month.
"This drug is already FDA-approved in the post-chemotherapy setting,
though it's not yet FDA-approved for use before chemotherapy," Beer said.
Dr Ash Tewari, chairman of urology at the Icahn School of Medicine at Mount
Sinai, in New York City, said enzalutamide works three different ways to
suppress androgens, making it a "triple threat".
"This study's findings are exciting, and may give us another tool to
fight this cancer," Tewari said. "And it was safe, with some minor
side effects but nothing unusual."
Another study scheduled for presentation at the meeting looked at men with
less advanced prostate cancer. This study found that adding radiation treatment
to anti-androgen therapy dropped the 10- and 15-year prostate-cancer-specific
death rate for men with locally advanced prostate cancer. Locally advanced
prostate cancer is cancer that has grown through the prostate, but hasn't yet travelled
to other areas of the body.
Surgery generally isn't an option for this type of cancer because it's
difficult to remove all of the cancer cells.
The study, from Norwegian researchers, included 11 years of follow-up
observation. Men who received hormone therapy alone had 10- and 15-year
prostate-cancer-specific death rates of 18.9% and 30.7%, respectively. The
rates for men who received radiation and hormone therapy were significantly
lower: 8.3% and 12.4%, respectively.
Because these studies were presented at a medical meeting, the data and
conclusions should be viewed as preliminary until they are published in
drugs cool hot flashes from prostate cancer therapy