The purpose of this study is to compare the radiographic progression-free survival (rPFS) of apalutamide in combination with abiraterone acetate (AA) plus prednisone or prednisolone (AAP) and AAP in participants with chemotherapy-naive (participants who did not receive any chemotherapy \[treatment of cancer using drugs\]) metastatic castration-resistant prostate cancer (mCRPC) (cancer of prostate gland \[gland that makes fluid that aids movement of sperm\]).
This is a randomized (study drug assigned by chance), double-blind (neither the Investigator nor the participant know the treatment) placebo-controlled and multicenter (when more than 1 hospital or medical school team work on a medical research study) study to determine if participants with chemotherapy-naive mCRPC will benefit from the addition of apalutamide to AAP compared with AAP alone. The study consists of 3 phases: Screening phase; Treatment phase, and Follow-up phase. At the final analysis, the study will be unblinded. After the Independent Data Monitoring Committee (IDMC) review and the sponsor's subsequent decision participants will be offered to receive treatment either in the Open-Label Extension Phase or the Long-Term Extension Phase of study. Participants' safety will be monitored throughout the study.
Participants will receive 240 mg (4\*60 mg tablets) of apalutamide once daily orally.
Participants will receive 1000 mg (4\*250 mg tablets) of abiraterone acetate (AA) once daily orally.
Participants will receive 5 mg tablet of prednisone twice daily orally.
Participants will receive matching placebo to apalutamide once daily orally.
Ciudad Automoma Buenos Aires, Argentina
Ciudad de Buenos Aires, Argentina
Córdoba, Argentina
La Rioja, Argentina
Mendoza, Argentina
Rosario, Argentina