Intermittent Androgen Deprivation Therapy for Stage IV Castration Sensitive Prostate Cancer

Inclusion Criteria: * Histologically or cytologically confirmed adenocarcinoma of the prostate. * \>75% prostate specific antigen (PSA) decline after 12 to 16 weeks of run in period with Gonadotropin-releasing Hormone (GnRH) analog abiraterone plus prednisone. * Performance status Eastern Cooperative Oncology Group (ECOG) 0-1 * Adequate organ function Serum alanine aminotransferase (ALT) or aspartate aminotransferase (AST) must be \< 2.5 x upper limit of normal (ULN), total bilirubin less than 1.5 X ULN, estimated creatinine clearance must be \>40 mL/min, absolute neutrophil count (ANC) \> 1500/l, hemoglobin above 9 g/dl, platelet count \> 100,000/l * Stable medical condition, including the absence of acute exacerbations of chronic illnesses, serious infections or major surgery within 28 days prior to study enrollment * Ability to give written informed consent Exclusion Criteria: * Prior GnRH analog with GnRH analogue for non-metastatic prostate cancer within 12 months prior to study enrollment or \>3 months of GnRH analog in the metastatic setting * Prior treatments with TAK-700/Orteronel, ketoconazole, apalutamide or enzalutamide. * Documented central nervous system metastases or liver metastasis * Prior surgical castration * Requiring opioids for cancer related pain. * Treatment with any investigational compound within 30 days prior to the first dose of study drugs * Diagnosis or treatment for another systemic malignancy within 2 years before the first dose of study dru…