New Drug May Help Some Prostate Cancer Patients
Study found Xofigo also improved quality of life for those whose cancer had spread to the bones
At the time the trial was stopped, 35 percent of the Xofigo group had died, versus 46 percent of the placebo group. One-quarter of men on the drug reported a "meaningful" improvement in their quality of life, compared with 16 percent of the placebo group.
There were side effects. Anywhere from 18 percent to 36 percent of men suffered nausea, diarrhea, constipation or fatigue; but most of those symptoms were just as common in the placebo group.
There were, though, more serious problems related to the body's ability to produce blood cells, which is handled by the bone marrow. Twelve percent of men on Xofigo developed thrombocytopenia, a drop in blood cells called platelets that can cause serious bleeding. That compared with 6 percent of the placebo group.
Another 5 percent of men on the drug developed neutropenia, a drop in the body's infection-fighting white blood cells.
For most men with prostate cancer, the tumor is slow-growing and never progresses to the point where it threatens their lives. According to the American Cancer Society, nearly all men with cancer confined to the prostate gland or nearby lymph nodes are still alive five years after their diagnosis -- and many can opt to delay having any treatment, and have the cancer monitored instead.
But the outlook is much more dim for men whose prostate cancer spreads to the bones or other distant sites. Only 28 percent are alive five years after their diagnosis.
"There are men who have serious disease, and in the years they do live they are often in pain, and in and out of the hospital," Vapiwala said.
Xofigo gives an option for at least some of them, she said.
Because the drug emits radioactive particles, it has to be given by a radiation oncologist or nuclear medicine specialist. So, smaller community hospitals may not be able to offer it, Vapiwala noted.
There's also cost. The course of six injections rings up at nearly $70,000.
The ultimate role of the drug in treating advanced prostate cancer is still in question, according to Vapiwala. A few other treatments -- hormonal therapy and two chemo drugs -- have been approved for these same patients in the past couple of years. And it's not known if Xofigo could, for example, be combined with any of those treatments.
"The right combination of treatments, and the right sequence, is still being studied," Vapiwala said.
And Parker added that no one knows yet if the drug could help people with other types of cancer that has spread to the bone. "In theory," he said, that should be the case. "But we do not yet have any data on this."
He noted that an ongoing trial is studying radium-223 for breast cancer that has spread to the bones.