IMAAGEN: Impact of Abiraterone Acetate in Prostate-Specific Antigen

This is a Phase 2, prospective, multicenter, open-label, single-arm study of abiraterone acetate plus prednisone in men with non-metastatic, castration-resistant prostate cancer (CRPC) who have a rising PSA despite castrate levels of testosterone. The study consists of Screening Phase (up to 4 weeks), Core Study Treatment Phase (comprised of six 28-day cycles), a Pre-metastatic Disease Follow-up Phase, an Optional Drug Holiday Phase; and a 30-day Safety Follow-up Visit. Each treatment cycle will last 28 days. Participating participants will receive study agents (Abiraterone acetate 1000 mg/day plus prednisone 5 mg/day, orally) continually during the study. If the partcipants elects to participate in the Optional Drug Holiday Phase, participants will discontinue abiraterone acetate plus prednisone and ADT. Participants will have the option to return to study medication during the first year of the Optional Drug Holiday Phase if there is evidence of rising PSA but no metastasis based on study imaging. If participants do no elect to participate, they will continue with the core study treatment as per protocol. The study will end when all participated participants have disease progression or end of the 2-year period (if participants participated in the Optional Drug Holiday Phase). Participants will be required to return to the study site 30 days after receiving the last dose of abiraterone acetate for safety follow-up.