Radiotherapy Combined With a LHRH (Ant)Agonist Versus Apalutamide in Patients With Biochemical Recurrence After RP

This is a phase II randomized, open-label study comparing salvage radiotherapy in combination with 6 months of androgen-deprivation therapy (ADT) with LHRH agonist or antagonist (arm A) versus anti-androgen therapy (AAT) with apalutamide 240mg daily (arm B) in hormone-naïve patients with biochemical progression after radical prostatectomy. All subjects will receive salvage radiotherapy as standard of care and will be randomly assigned in a 1:1 ratio to receive either 6 months of androgen-deprivation therapy (ADT) with LHRH agonist or antagonist through 6 monthly, two 3-monthly or one 6-monthly injections (control arm) or 6 28-day cycles of apalutamide 240mg daily (interventional arm). The study will include a screening phase, treatment phase, and a post-treatment phase. The primary objective of the trial is to compare sexual function between the 2 groups based on the Expanded Prostate cancer Index Composite (EPIC)-26 sexual domain scores at 9 months after start of hormonal treatment.