A Study to Evaluate the Potential Increased Risk of Seizures Among Metastatic Castration-Resistant Prostate Cancer (mCRPC) Patients Treated With Enzalutamide

This was a multicenter, single-arm, open-label, postmarketing safety study to evaluate the risk of seizure among patients with mCRPC treated with enzalutamide who were at potential increased risk of seizure. Participants who met all inclusion and none of the exclusion criteria were enrolled into the study and participated in a 4-month treatment period, during which once daily dosing of enzalutamide (160 mg/day) occurred. At the end of the 4-month treatment period, participants who were assessed as deriving benefit from enzalutamide treatment were allowed to continue in the extension period where participants continued to receive enzalutamide until 1 of the following criteria was met: 1. The participant experienced bone disease progression per Prostate Cancer Working Group 2 (PCWG2) guidelines or soft tissue disease progression per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 2. The participant initiated treatment with another anticancer therapy or, in the opinion of the investigator, continued dosing would have led to undue risk to the patient 3. The participant met a discontinuation criterion 4. The sponsor terminated the study Participants who continued to receive clinical benefit from treatment with enzalutamide and did not meet any discontinuation criteria may have transitioned to an open label roll-over extension study upon approval of the study protocol at the institution where they were receiving treatment. Participants who did not continue in the extension period or who met a discontinuation criterion were discontinued from enzalutamide therapy and completed a follow-up visit 30 days from the last dose of enzalutamide or prior to the initiation of another anticancer therapy, whichever occurred first. For participants who continued on treatment after the 12-month extension period, data collection was limited to dosing information, concomitant medications, and all adverse events (AEs) including serious adverse events (SAEs).