A Study to Test if Enzalutamide is Effective and Safe in Prostate Cancer Patients Who Have Never Had Hormone Therapy

A PSA response was defined as a decline from Baseline in PSA level of 80% or greater. Blood samples for PSA were collected and analyzed at a central laboratory. Participants with an unknown or missing response or who discontinued prior to week 25 for any reason were treated as non-responders.

Each adverse event (AE) was assessed by the investigator for causal relationship to the study drug; those deemed possibly or probably related to study drug are reported as drug regimen related AEs (DRRAEs).

A serious adverse event (SAE) was defined as any untoward medical occurrence that at any dose:

• Resulted in death
• Was life-threatening
• Resulted in persistent or significant disability/incapacity
• Resulted in congenital anomaly or birth defect
• Required inpatient hospitalization or led to prolongation of hospitalization
• Other medically important events.

A PSA response was defined as a decline from baseline in PSA level of 80% or greater. Blood samples for PSA were collected and analyzed at a central laboratory. Participants with an unknown or missing response or who discontinued prior to week 49, week 97 or week 169 for any reason were treated as non-responders.

Participants with unknown or missing PSA results at week 25 or who discontinued prior to week 25 were considered non-responders at week 25. Participants with unknown or missing PSA results at week 49, week 97 or week 169 were considered non-responders.

Participants with unknown or missing PSA results at week 25 or who discontinued prior to Week 25 were considered non-responders at Week 25. Participants with unknown or missing PSA results at week 49, 97 and 169 were considered non-responders.

Participants with unknown or missing PSA results at week 25 or who discontinued prior to week 25 were considered non-responders at week 25. Participants with unknown or missing PSA results at week 49, 97 or 169 were considered non-responders.

The maximum decline from Baseline in PSA was calculated as the largest reduction from Baseline in PSA level that occurred at any point after treatment start up to week 25 and up to and including the assessment made at the safety follow-up visit, divided by the PSA Baseline value and multiplied by 100, i.e., the maximum percent change from baseline.

Time to PSA response (PSA decline ≥ 80% from Baseline) is defined as the time interval from the first study drug dose to the first date a decline from Baseline in PSA level of 80% or greater was recorded. Time to response was estimated using the Kaplan-Meier method.

Time to PSA decline ≥ 90% is defined as the time interval from the first study drug dose to the first date a decline from Baseline in PSA level of 90% or greater was recorded. Time to PSA decline ≥ 90% was estimated using the Kaplan-Meier method.

Time to PSA ≤ 4 ng/ml is defined as the time interval from the first study drug dose to the first date a decline in PSA to a result of 4 ng/ml or below was recorded. Time to PSA ≤ 4 ng/ml was estimated using the Kaplan-Meier method.

Time to PSA ≤ 0.1 ng/ml is defined as the time interval from the first study drug dose to the first date a decline in PSA to a result of 0.1 ng/ml or below was recorded.

Time to PSA ≤ 0.1 ng/ml was estimated using the Kaplan-Meier method.

Time to PSA progression is defined as the time interval from the first study drug dose to the first date of PSA progression. PSA progression is defined as a ≥ 25% increase in PSA with an absolute increase of ≥ 2 ng/mL above the nadir unless the PSA next measurement(s), if available, does not confirm the PSA progression.

PSA doubling time was to be calculated from the slope estimated from a linear regression of the natural log of PSA fitted on time, if the slope was positive. Since the slope was negative for all participants, PSA doubling time could not be calculated.