Approximately 40 subjects will be enrolled to obtain 30 evaluable subjects. All subjects will receive Radium Ra 223 dichloride every 4 weeks for a total of 6 doses over 24 weeks and concurrent Enzalutamide for a minimum duration of 24 weeks. The sponsor will provide Enzalutamide after the End of Treatment visit until the last Long Term Follow Up visit has been completed. Subjects will continue to receive Enzalutamide as long as a positive response to therapy is demonstrated. Enzalutamide may be discontinued at any time per physician discretion.