The purpose of this study is to show that abiraterone acetate plus prednisone added to the current standard of care, gonadotropin-releasing hormone (GnRH) decreases prostate specific antigen (PSA) and prolongs the time until it is evident that the cancer has grown. Additionally, safety information about abiraterone acetate in combination with prednisone will be collected. This will include looking at what side effects occur, how often they occur, and for how long they last.
This is a Phase 2, prospective, multicenter, open-label (both the patient and investigator will know what treatment is taken), single-arm study of abiraterone acetate plus prednisone in patients with non-metastatic (has not spread in the body), advanced prostate cancer with a rising PSA despite current treatment with GnRH monotherapy. This study has 4 phases: Screening Phase (up to 14 Days); Core Study Treatment Phase (Treatment-Cycle 1-6); Follow-up Phase (Treatment-Cycle 7- until disease progression); and an Extension Phase (after the end of the official study). Each treatment cycle will last 28 days (about a month). Your participation in the study will include a screening period of up to 14 days, which allows the doctor to assess whether or not you qualify for the study. There is a Core Treatment Phase where study medication is taken for six treatment cycles (about 6 months). There is a Follow-up Phase where study medication will continue to be taken until your prostate cancer progresses, or you have unacceptable toxicities or this phase of the study ends (approximately 18 months). If your prostate cancer progresses before the end of the follow-up phase, you will not be given further study medication. However, the study doctor will contact you about every 2 months to record any new therapy for prostate cancer you are taking until the end of the follow-up phase. If for some reason you stop study medication before the end of the follow-up phase, the study doctor will contact you about every 2 months to record any new therapy for prostate cancer you are taking until the end of the follow-up phase or until your prostate cancer progresses, whichever happens first. You will be required to return to the study site 30 days after receiving your last dose of abiraterone acetate for safety follow-up. You may be in the study for about 24 months. Four abiraterone acetate tablets should be taken by mouth [PO] at least 2 hours after eating & no food should be eaten for at least 1 hour afterward. Two (2.5 mg) prednisone tablets will be taken PO once daily, preferably with food. Patients may continue abiraterone acetate until disease progression, until unacceptable toxicities develop, until abiraterone acetate becomes commercially available for the indication being studied, or until the sponsor determines it is necessary to stop the study.