First drug approved for castration-resistant prostate cancer with bone tumor symptoms

The authors analyzed the effect of radium-223 dichloride (Xofigo) in treating castratation-resistant prostate cancer with symptoms of bone tumors. 

Hormone therapy is a common treatment in prostate cancer. It targets the male sex hormones active in prostate cancer, such as testosterone. Some patients may develop a resistance to hormone therapy. This is known as castration-resistant prostate cancer. It also means that patients will no longer respond to hormone therapy. In some patients, prostate cancer can progress and will lead to the growth of tumors in the bones. Radium-223 dichloride is the first drug available to treat castration-resistant prostate cancer with symptoms of bone tumors. This drug functions by applying radiation to the bone tumor sites.

Further studies are required to determine the outcomes of radium-223 dichloride in prostate cancer.

The authors aimed to review the safety and effectiveness of radium-223 dichloride in treating castration-resistant prostate cancer with symptoms of bone tumors.

In a large study of 921 patients, patients who received radium-223 dichloride  had an overall survival (patients who were still alive following the treatment) of 14.9 months compared to 11.3 months in the placebo group. There was a 26% to 38% reduced risk of dying from prostate caner for patients who received radium-223 dichloride, compared to the placebo group. Patients who received radium-223 dichloride reported a significant delay from the treatment until first bone tumor symptoms were experienced (15.6 months). For the placebo group, this was 9.8 months.

36% of radium-223 dichloride patients required pain relief drugs compared to 50% of placebo patients. 50% of radium-223 dichloride patients reported bone pain as a treatment related side effect compared to 62% of placebo patients. Grade 3 or 4 (severe or life-threatening side effects) was experienced by 56% of the radium-223 dichloride group compared to 62% in the placebo group. The most common side effects were bone pain, stomach or intestine pain and blood abnormalities (e.g. blood clots, low blood cell count).

The authors concluded that radium-223 dichloride improved overall survival and was well tolerated by patients with castration-resistant prostate cancer with symptoms of bone cancer.