Men with castration-resistant prostate cancer (CRPC) and bone metastases (BM) will often have debilitating pain that impacts every aspect of their daily functioning thus significantly diminishing their quality of life (QoL). Finding the best drug or treatment to control the pain will allow men to have a more complete and fulfilling life as well as increase their QoL.

Phase III clinical trials have demonstrated the superiority of the drug Denosumab over Zoledronic acid (Za) in delaying or preventing the development of skeletal-related events which is defined as pathological fractures, having radiation or surgery to the bone and spinal cord compression in men with CRPC and who have BM.  An ad-hoc analysis of this trial showed that Denosumab is superior to ZA for pain interference (PI) and cancer specific quality of life (QoL), focusing on the subgroup of men with no or mild pain at baseline.

The subjects were men with CRPC and BM who had no prior IV bisphosphonate treatment.  They were randomized to receive either Denosumab (120 mg+IV placebo) or placebo+IV Zoledronic Acid 4mg (adju