Researchers offer new options for men whose prostate cancer has spread to bones

Dartmouth-Hitchcock Norris Cotton Cancer Center has treated three men with a recently FDA-approved treatment, which offers new options for men whose prostate cancer has spread to their bones. The treatment's trade name is Xofigo^® (or radium-223 dichloride). It is an alpha particle-emitting radioactive therapeutic agent with an anti-tumor effect.

Treatment entails an injection each week, up to six injections if needed. "When compared with the best existing standard of care, research shows that patients receiving radium-223 injections live longer," said Thomas C. Sroka, MD, PhD, radiation oncologist, Norris Cotton Cancer Center. "It is also very tolerable," he said, "with few side effects."

Sroka explains that the agent is made to look like calcium so it is easily absorbed into the bone. "This radioisotope is precise, settling into the right place, with minimal damage to surrounding tissue," said Sroka. It targets area of increased bone turnover, which is the case in bone metastases. The high-energy alpha-particle from Radium-223 deposits its energy over a very short distance (less than 100 micrometers), which is how it limits damage to surrounding normal tissue.

Xofigo was approved by FDA in May of 2013 and is the first agent of its kind. Clinical trials of the drug showed an improvement of overall survival time from 11.3 months to 14.9 months versus placebo. The most common side effects are nausea, diarrhea, vomiting, and peripheral edema.

Prostate cancer is the most common cancer among men in the United States. If it spreads to other places in the body, prostate cancer predominantly settles in the bones. Bone metastases are a leading cause of death in men with prostate cancer.