Advanced ChemoHormonal Therapy for Treatment Naive Metastatic Prostate Cancer

PRIMARY OBJECTIVE: I. Efficacy of apalutamide in combination with abiraterone acetate + prednisone following docetaxel with ongoing androgen deprivation therapy in men with high risk metastatic castration sensitive disease. SECONDARY OBJECTIVES: I. Safety and tolerability of apalutamide in combination with abiraterone acetate + prednisone following docetaxel with ongoing androgen deprivation therapy. II. Time to event. III. Depth of prostate specific antigen (PSA) response. EXPLORATORY OBJECTIVES: I. Quality of life. II. Falls. III. Molecular changes from prostate cancer over time. OUTLINE: Patients receive apalutamide orally (PO) once daily (QD), abiraterone acetate PO QD, and prednisone PO QD. Cycles repeat every 4 weeks in the absence of disease progression or unacceptable toxicity. Patients also receive androgen deprivation therapy per standard of care. Patients undergo computed tomography (CT) scan, bone scan and blood sample collection throughout the study. After completion of study treatment, patients are followed up every 6 months for up to 10 years.