A QT/QTc and Multi-Dose Pharmacokinetic Study of Abiraterone Acetate Plus Prednisone in Patients With Metastatic Castration-Resistant Prostate Cancer

This is an open-label (identity of assigned study drugs will be known) study to evaluate the effects of abiraterone acetate plus prednisone on the conduction of electric charges within the heart in male patients diagnosed with metastatic castration-resistant prostate cancer (a progressive form of prostate cancer that spreads to other parts of the body). At various time points outline in the protocol from Day -1 of Cycle 1 up to Day 2 of Cycle 2, patients will have electrocardiograms extracted from a 24 hour holter-monitor to evaluate the electrical activity of their heart. Efficacy will be assessed according to Prostate Cancer Working Group 2 and modified Response Evaluation Criteria In Solid Tumors criteria. Serial blood samples for pharmacokinetic analysis (how the drug concentrations change over time) will be collected and safety will be monitored throughout the study. Patients will take 1000 mg of abiraterone acetate once daily plus prednisone 5 mg twice daily orally (by mouth) until disease progression and will be followed up for up to 60 months.