A Study to Assess the Safety of Continued Administration of MDV3100 in Subjects With Prostate Cancer Who Showed Benefit From Prior Exposure to MDV3100

This was a multi-center extension study in participants with prostate cancer who have completed MDV3100 treatment study to assess the long-term safety of continued administration of MDV3100, when judged by the investigator to be in the best interest of the participant. For the study duration, all participants with castration-resistant prostate cancer (CRPC) maintained androgen deprivation with a Luteinizing Hormone Releasing Hormone (LHRH) agonist/antagonist unless they underwent bilateral orchiectomy. Participants were discontinued from study drug when the continued administration of study drug was deemed to be not in the participants' best interest by the investigator based on clinical assessment. Throughout the study, safety and tolerability were assessed by the recording of adverse events, monitoring of vital signs and physical examinations, safety laboratory evaluations, and 12-lead electrocardiograms (ECGs). Participants had a safety follow-up visit 30 days after their last dose of study drug. Participants that did not meet any of the discontinuation criteria were eligible to continue to receive treatment with enzalutamide in study 9785-CL-0123 \[NCT02960022\] upon approval and activation of the study at the participating institution. Participants who enrolled in study 9785-CL-0123 \[NCT02960022\] were not required to have a safety follow-up visit.