Radium-223 dichloride (radium-223) is in development as an intravenous injection for treating cancer patients with bone metastases.
With similar properties to calcium, radium-223 is drawn to places where calcium is used to build bone in the body, including the site of faster, abnormal bone growth – such as that seen in the skeletal metastases of men with advanced, castration-resistant prostate cancer.
Radium-223, after injection, is carried in the bloodstream to sites of abnormal bone growth. The place where a cancer starts in the body is known as the primary tumor. Some of these cells may break away and be carried in the bloodstream to another part of the body. The cancer cells may then settle in that part of the body and form a new tumor. If this happens it is called a secondary cancer or a metastasis.
Most patients with late stage prostate cancer suffer the maximum burden of disease in their bones. The aim with radium-223 is to selectively target this secondary cancer. Any radium-223 not taken-up in the bones is quickly routed to the gut and excreted.
"In the phase III ALSYMPCA study, CRPC patients treated with radium-223 showed a significant improvement in overall survival compared to placebo"