An Efficacy and Safety Study of Apalutamide (JNJ-56021927) in Combination With Abiraterone Acetate and Prednisone Versus Abiraterone Acetate and Prednisone in Participants With Chemotherapy-naive Metastatic Castration-resistant Prostate Cancer (mCRPC)

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. Participants' safety will be monitored throughout the study.

Inclusion Criteria:

- Adenocarcinoma of the prostate

- Metastatic disease as documented by technetium-99m (99mTc) bone scan or metastatic
lesions by computed tomography (CT) or magnetic resonance imaging (MRI) scans
(visceral or lymph node disease). If lymph node metastasis is the only evidence of
metastasis, it must be greater than or equal to (>=) 2 centimeter (cm) in the longest
diameter

- Castration-resistant prostate cancer demonstrated during continuous androgen
deprivation therapy (ADT), defined as 3 rises of PSA, at least 1 week apart with the
last androgen deprivation therapy (PSA) >= 2 nanogram per milliliters (ng/mL)

- Participants who received a first generation anti-androgen (eg, bicalutamide,
flutamide, nilutamide) must have at least a 6-week washout prior to randomization and
must show continuing disease (PSA) progression (an increase in PSA) after the washout
period

- Prostate cancer progression documented by prostate-specific antigen (PSA) according to
the Prostate Cancer Clinical Trials Working Group (PCWG2) or radiographic progression
of soft tissue according to modified Response Evaluation Criteria in Solid Tumors,
version 1.1 (RECIST) modified based on PCWG2, or radiographic progression of bone
according to PCWG2

Exclusion Criteria:

- Small cell or neuroendocrine carcinoma of the prostate

- Known brain metastases

- Prior chemotherapy for prostate cancer, except if administered in the
adjuvant/neoadjuvant setting

- Previously treated with ketoconazole for prostate cancer for greater than 7 days

- Therapies that must be discontinued or substituted at least 4 weeks prior to
randomization include the following: a) Medications known to lower the seizure
threshold, b) Herbal and non-herbal products that may decrease PSA levels (example
[eg], saw palmetto, pomegranate) or c) Any investigational agent

- At Screening need for parenteral or oral opioid analgesics (eg, codeine,
dextropropoxyphene)