[Radium 223 in castration resistant prostate cancer.]

OBJECTIVE: To analyze the available evidence on Radium 223 therapy, an alfa particle emitter with specific action on bone metastases, studied on patients with castration resistant prostate cancer.

EVIDENCE ACQUISITION: We review the pivotal study ALSYMPCA, that served to get the drug approval for this phase of the disease, and the new data obtained from its use. We also performed a search of ongoing studies with Radium 223 alone or in combination with other molecules.

EVIDENCE SINTHESIS: According to the ALSYMPCA study, Radium 223 significantly prolongs the overall survival of patients with castration resistant prostate cancer and bone metastases; approximately 3.6 months in comparison with patients who received placebo, which turns into a median life expectancy of 14.9 months, and a 36-month survival of 46%, associated with a 30% reduction in death risk. Overall survival results were consistent both in patients who receive Docetaxel previously and those who did not.

RESULTS: for secondary variables support the positive effect of Radium 223 therapy on symptomatic skeletal events (for example, the use of external beam radiotherapy to alleviate pain) and bone markers, confirming its efficacy in bone metastases.

CONCLUSIONS: Radium 223 is the first treatment directed to bone that has demonstrated significant improvement on overall survival. It also prolonged the time to the first skeletal event and the median time to PSA increase significantly. All this in addition to its manageable adverse effects, lower than those appeared in the placebo arm of the pivotal study ALSYMPCA.