PROSTATE-IQ: Parallel RandOmized STudy of Personalized Apalutamide Treatment and Evaluation to Improve Quality of Life in Post-Operative Radiation With Androgen Axis Suppression. A Phase III Multi-center Study for Men With Detectable PSA After Prostatectomy for Prostate Cancer.

Primary Objective: ARTERA LOW COHORT (less aggressive disease) 1\) To compare fatigue at 9 months, as assessed by FACIT-F, between participants assigned to six months of apalutamide monotherapy versus six months of GnRH-based ADT. HIGHER RISK COHORT (more aggressive disease) 1\) To compare fatigue at 24 months, as assessed by FACIT-fatigue, between participants assigned to six months of GnRH-based ADT plus apalutamide monotherapy versus 24 months of GnRH-based ADT. Secondary Objectives for both Cohorts: 1. To compare patient-reported quality of life for the two treatment arms (Arm 1 vs.…