Study of Abiraterone Acetate Plus Prednisone in Patients With Chemo-naive Metastatic Castration-Resistant Prostate Cancer

• Time to prostate specific antigen (PSA) progression (TTPP) [ Time Frame: 14 months ] [ Designated as safety issue: No ]
  Measured from the time interval from the date of randomization to the date of the PSA progression based on prostate cancer clinical trials working group 2 (PCWG2) criteria
  
  

• Overall survival [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  The percentage of people in a study or treatment group who are alive from date of randomization to date of death
  
  
• Time to initiation of cytotoxic chemotherapy [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  Date of randomization to date of initiation of chemotherapy
  
  
• Prostate specific antigen (PSA) response rate [ Time Frame: 14 months ] [ Designated as safety issue: No ]
  Proportion of patients achieving a PSA decline 50% according to prostate cancer clinical trials working group 2 (PCWG2) criteria
  
  
• Objective response rate [ Time Frame: 14 months ] [ Designated as safety issue: No ]
  Measurable disease based on modified response evaluation criteria in solid tumors (RECIST) criteria and baseline lymph node size must be 2.0 cm to be considered target or evaluable lesion for RECIST criteria
  
  
• Quality of life (QoL) total score and each subscale score [ Time Frame: 14 months ] [ Designated as safety issue: No ]
  Assessed by functional assessment of cancer therapy-prostate (FACT-P)
  
  
• Time to pain progression [ Time Frame: 14 months ] [ Designated as safety issue: No ]
  Assessed by the Brief Pain Inventory Short Form (BPI-SF) and analgesic score
  
  
• Time to Eastern Cooperative Oncology Group (ECOG) performance status score determination [ Time Frame: 14 months ] [ Designated as safety issue: No ]
  ECOG performance status score 0 (Fully active, able to carry on all pre-disease performance without restriction) versus 1 (Restricted in physically strenuous activity but ambulatory and able to carry out work on a light or sedentary nature, eg, light housework, office work)
  
  
• Collection of safety data including adverse events [ Time Frame: 5 years ] [ Designated as safety issue: Yes ]
  

This is a multinational, multicenter, randomized (the study drug is assigned by chance), double-blind (neither physician nor patient knows the treatment that the patient receives), placebo-controlled (an inactive substance that is compared with a drug to test whether the drug has a real effect in a clinical trial) study. All patients will be randomly assigned in a 1:1 ratio between the abiraterone acetate group (abiraterone acetate and prednisone) and the placebo group (placebo and prednisone). The study will consist of a screening phase (within 28 days prior randomization on Cycle 1, Day 1), a treatment phase (28-day cycles until disease progression), and a follow-up phase (all patients will be contacted for every 3 months up to Month 60, focusing primarily on survival status). Patients will receive either abiraterone acetate 1,000 mg daily and prednisone 5 mg twice daily or placebo and prednisone 5 mg twice daily.