Enzalutamide With or Without Radium Ra 223 Dichloride in Patients With Metastatic, Castration-Resistant Prostate Cancer

This randomized phase II trial studies how well enzalutamide with or without radium Ra 223 dichloride in treating patients with castration-resistant prostate cancer that has spread to other places in the body. Enzalutamide is an androgen receptor inhibitor that may slow down the growth of prostate cancer by blocking the action of the male hormone testosterone and other male hormones called androgens. Radiation therapy uses high energy alpha particles to kill tumor cells and shrink tumors. Enzalutamide with or without radium Ra 223 dichloride may work better in treating patients with castration-resistant prostate cancer.