Abiraterone

Radiographic PFS was defined as the time (in months) interval from randomization to the first date of radiographic progression or death. Radiographic progression included progression by bone scan (according to modified Prostate Cancer Working Group 2 \[PCWG2\] criteria), defined as at least 2 new lesions on bone scan and progression of soft tissue lesions by computed tomography (CT) or magnetic resonance imaging (MRI) (according to Response Evaluation Criteria in Solid Tumors \[RECIST\] 1.1 criteria). As per the RECIST 1.1 guideline, progression requires a 20 percent (%) increase in the sum of diameters of all target lesions and a minimum absolute increase of 5 millimeter (mm) in the sum as compared to nadir sum of diameter.

Overall survival was defined as the time from randomization to date of death from any cause.

Time to PSA progression was defined as time interval from the date of randomization to the date of the prostate-specific antigen (PSA) progression as defined in the Prostate Specific Antigen Working Group (PSAWG) criteria. PSAWG criteria- Decline from baseline and reach response criteria: greater than or equal to (\>=) 50 percent (%) increase over the nadir and the increase in the absolute-value by at least 5 nanogram per milliliter (ng/mL) (or back to the baseline), which is confirmed by a second value 4 or more weeks later; Decline from baseline but not reach response criteria: \>=25% increase over the nadir and the increase in the absolute-value by at least 5 ng/mL, which is confirmed by a second value 4 or more weeks later; and No decline from baseline: \>=25% increase over the baseline and the increase in the absolute-value by at least 5 ng/mL, which is confirmed by a second value 4 or more weeks later.

An SAE is defined as any untoward medical occurrence that results in death, is life-threatening, requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent or significant disability/incapacity, leads to a congenital anomaly/birth defect in the offspring of a participant, or is an important medical event.

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 is defined as the time from randomization to date of death from any cause.

The rPFS was defined as the time from randomization to the occurrence of one of the following: 1) a participant was considered to have progressed by bone scan if - a) the first bone scan with greater than or equal to (\>=) 2 new lesions compared to baseline was observed in less than (\<) 12 weeks from randomization and was confirmed by a second bone scan taken \>=6 weeks later showing \>=2 additional new lesions (a total of \>=4 new lesions compared to baseline), b) the first bone scan with \>=2 new lesions compared to baseline was observed in \>=12 weeks from randomization and the new lesions were verified on the next bone scan \>=6 weeks later (a total of \>=2 new lesions compared to baseline); 2) progression of soft tissue lesions measured by computerized tomography (CT) or magnetic resonance imaging (MRI); 3) death from any cause.

number of patients with ≥ 30% PSA decline after 12 weeks of abiraterone treatment

The complete PSA response is defined as a PSA =\< 0.2 ng/ml, confirmed with a 2nd measurement at least 3 weeks later. The estimated PSA response rate will be computed with 95% exact confidence interval. Binomial exact test will be used to determine whether the complete PSA response rate is significantly greater than 43%.

Time to PSA progression was calculated from date of enrollment to the date of first documentation of PSA progression. As per Prostate Cancer Clinical Trials Working Group (PCWG2) criteria, PSA progression was defined as greater than or equal to (\>=) 25 percent (%) and \>=2 nanogram/milliliter (ng/mL) after 12 weeks (in case of no decline in PSA from Baseline), or first PSA increase that is \>=25% and \>=2 ng/mL above the nadir, and which was confirmed by a second value 3 or more weeks later (in case of decline of PSA from Baseline).

No mineralocorticoid excess is defined as experiencing neither of the 2 mineralocorticoid excess toxicities, that is, neither hypokalemia nor hypertension.

The PSA response will be evaluated according to Prostate-Specific Antigen Working Group (PSAWG) criterion, which is, greater than or equal to 50 percent decrease in PSA from Baseline up to 12 weeks after the first dose of study drug, which would be subsequently confirmed by a measurement that is at least 4 or more weeks after initial documentation of PSA.

The PSA response will be evaluated according to Prostate-Specific Antigen Working Group (PSAWG) criterion, which is, greater than or equal to 50 percent decrease in PSA from Baseline up to 12 weeks after the first dose of study drug, which would be subsequently confirmed by a measurement that is at least 4 or more weeks after initial documentation of PSA.

AE is any untoward medical occurrence in participant who received study drug without regard to possibility of causal relationship. Events with Grade 3 or higher (3=Severe; 4=life-threatening; 5=fatal) are events that significantly interrupt usual daily activity, require systemic drug therapy/other treatment and are, in many situations, considered unacceptable or intolerable events.

The PSA response was evaluated according to Prostate-Specific Antigen Working Group (PSAWG) criterion, which is, greater than or equal to 50 percent decrease in PSA from Baseline during the study, which would be subsequently confirmed by a measurement that is at least 4 or more weeks after initial documentation of PSA response.

Progression-free survival was defined as the time from randomization to first occurrence of disease progression (either radiographic or clinical), or death from any cause. PFS was determined using radiographic progression defined by Response Evaluation Criteria in Solid Tumors (RECIST) on measurable lesions captured by computed tomography (CT) or magnetic resonance imaging (MRI). Clinical disease progression was considered only when disease progression could not be confirmed by CT or MRI, such as when the disease site is skin, bone marrow, or central nervous system.

Percentage of participants with greater than or equal to 50 percent decrease in PSA levels was assessed.

Testosterone is a potent androgen (a hormone that promotes the development and maintenance of male characteristics) and major product secreted by cells in the testis and produced in the adrenal glands and by prostate cancers. Abiraterone acetate affects sources of testosterone in the body (ie, adrendal gland and prostate tumor). Testosterone concentration was measured in prostate tissues after exposure to study treatments at Week 12.

The DHT is a potent androgenic metabolite of testosterone and the concentration of DHT was measured in prostate tissues after exposure to study treatments at Week 12.

The Cmax is the maximum observed plasma concentration of abiraterone acetate.

The AUC (0-last) is the area under the plasma abiraterone acetate concentration-time curve from time zero to time of the last quantifiable concentration.

The AUC (0-infinity) is the area under the plasma abiraterone acetate concentration-time curve from time 0 to infinite time, calculated as the sum of AUC (0-last) and C(last)/lambda(z), in which AUC(0-last) is area under the plasma abiraterone acetate concentration-time curve from time zero to time of the last quantifiable concentration, C(last) is the last observed quantifiable concentration and lambda(z) is elimination rate constant.

Pharmacokinetic parameter Cmax of abiraterone (coated, reformulated tablet and uncoated, current commercial tablet) will be measured when abiraterone acetate is administered as a single oral 1000-mg dose.

Pharmacokinetic parameter AUC of abiraterone (coated, reformulated tablet and uncoated, current commercial tablet) will be measured when abiraterone acetate is administered as a single oral 1000-mg dose.

Pharmacokinetic parameter Cmax of abiraterone was measured when abiraterone acetate was administered in Period 1 and Period 2.

Pharmacokinetic parameter AUC of abiraterone was measured when abiraterone acetate was administered in Period 1 and Period 2.

Pharmacokinetic parameter tmax of abiraterone was measured when abiraterone acetate was administered in Period 1 and Period 2.

Pharmacokinetic parameter t1/2 of abiraterone was measured when abiraterone acetate was administered in Period 1 and Period 2.

Normalization or reduction of age-appropriate androstenedione levels will be determined by the mean of the androstenedione values measured on Study Days 6 and 7 of the treatment period.

The MTD is the highest dose of a drug or treatment that does not cause unacceptable side effects.

Number of participants with greater than or equal to 50 percent decrease in PSA levels were assessed. PSA decline was evaluated according to (Prostate Specific Antigen Working Group) PSAWG criteria. Decrease in PSA levels represented improvement.