Jan. 31, 2012 -- An experimental pill that works differently than other prostate cancer drugs extended the lives of men with spreading cancer by an average of nearly five months.
Men with late-stage prostate cancer given the new hormone treatment, MDV3100, lived an average of nearly a year-and-a-half from the time they started taking the treatment, compared with fewer than 14 months for those given placebo.
MDV3100 works differently than other hormone treatments, launching a three-pronged attack against testosterone and its related hormones, called androgens, which fuel prostate cancer growth.
All the men had cancers that continued to spread despite previous hormonal therapy and chemotherapy.
"About 32,000 men die of prostate cancer each year in the U.S., and virtually all the deaths are due to this type of cancer," says Howard I. Scher, MD, chief of the genitourinary oncology service at Memorial Sloan-Kettering Cancer Center in New York.
Researchers not involved with the study were impressed by the results.
Scher presented the findings at a news briefing in advance of the fourth annual Genitourinary Cancers Symposium, being held later this week in San Francisco. He is an unpaid consultant for Medivation, which makes the drug and funded the trial.
The survival edge was so substantial that the late-stage study was halted early so men taking placebo could be offered MDV3100. Results of the study are being submitted to the FDA in anticipation of gaining approval, Scher tells WebMD.
If approved, MDV3100 would join a growing number of drugs for late-stage disease. Most recently, the prostate cancer pill Zytiga got the nod from the FDA after a large study showed it may extend life by up to four months.
"The major difference is that Zytiga requires that men also receive prednisone, which produces side effects like fluid retention that have to be managed. MDV3100 does not," Scher says.
A Visual Guide to Prostate Cancer
In the study, called AFFIRM, almost 1,200 men were given MDV3100 or a placebo.
In addition to living longer, men who took the new pill were more likely to experience drops in levels of prostate-specific antigen (PSA) than men who received placebo. Elevated levels of PSA may be an indicator for prostate cancer.