Prostate cancers initially need the male hormone testosterone for growth. Hormone therapies that lower the level of testosterone are among the most effective treatments for prostate cancers that have spread to other organs (metastasized). The benefits of hormone treatments do not last, however. Over time, many prostate cancers continue to grow despite hormonal therapies (¿castration-resistant¿ prostate cancer). It is not unusual for castration-resistant prostate cancer to metastasize to the bone and cause pain.
The purpose of this study is to evaluate the safety and effectiveness of a treatment called Alpharadin in men with castration-resistant prostate cancer who have bone metastases. Alpharadin is radium-223 chloride, a liquid that contains a radioactive element that specifically targets prostate cancer that has metastasized to bone. The radiation that radium-223 gives out travels only a very short distance in the body, and therefore acts mainly on the areas of the bones that require treatment: bone metastases.