Inclusion Criteria:

          -  Willing and able to provide informed consent;

          -  Histologically confirmed adenocarcinoma of the prostate without neuroendocrine
             differentiation or small cell features with a minimum of 3 cores positive for tumour;

          -  Tumour biopsy tissue accessible for downstream evaluation;

          -  Must be candidates for radical prostatectomy and considered surgically resectable by
             urologic evaluation;

          -  High Risk D'Amico score defined as either PSA > 20, Gleason score ≥ 8 as determined by
             the local pathologist; or T2c-3 based on DRE, pathologic review +/- imaging;

          -  Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 1;

          -  No evidence of metastatic disease or nodal disease as determined by radionuclide bone
             scans and computed tomography (CT)/magnetic resonance imaging (MRI); non-pathological
             lymph nodes must be less than 15 mm in the short (transverse) axis;

          -  Able to swallow the study drug(s) as prescribed and comply with study requirements;

          -  Required initial laboratory values:

          -  Absolute neutrophil count (ANC) ≥ 1500/μL;

          -  Platelet count ≥ 100,000/μL;

          -  Hemoglobin ≥ 90 g/L;

          -  Creatinine ≤ 175 μmol/L;

          -  Bilirubin ≤ upper limit of institutional normal (ULN);

          -  AST/ALT ≤ 1.5 × ULN.

        Exclusion Criteria:

          -  Received an investigational agent within 4 weeks prior to screening;

          -  Stage T4 prostate cancer by clinical examination or radiologic evaluation;

          -  Hypogonadism or severe androgen deficiency as defined by screening serum testosterone
             below the normal range for the institution;

          -  Prior androgen deprivation, chemotherapy, surgery, or radiation for prostate cancer;

          -  Receiving concurrent androgens, estrogens, or progestational agents, or received any
             of these agents within the 6 months prior to randomization;

          -  History of another malignancy within the previous 5 years other than curatively
             treated nonmelanomatous skin cancer and non-muscle invasive bladder cancer;

          -  Uncontrolled intercurrent illness including, but not limited to, ongoing or active
             infection, cardiovascular disease, unstable angina pectoris, cardiac arrhythmia that
             is symptomatic or requires active therapy; deep venous thrombosis within 3 months
             prior to randomization;

          -  Previous use, or participation in a clinical trial, of an investigational agent that
             blocks androgen synthesis (e.g., abiraterone acetate, TAK-700, TAK-683, TAK-448) or
             targets the androgen receptor (e.g., enzalutamide, BMS 641988);

          -  Liver injury or disease (e.g., viral hepatitis, liver failure Child-Pugh Class C).