A Study of Apalutamide (Adjuvant Treatment) and Androgen Deprivation Therapy (ADT) in Participants Who Have Undergone Radical Prostatectomy (RP) for Non-metastatic Prostate Cancer and Who Are at High Risk for Metastases

Main Study: The purpose of main study is to assess if the combination of apalutamide and androgen deprivation therapy (ADT) in participants with high-risk localized prostate cancer improves the biochemical recurrence (BCR) free rate. Sub-study: The purpose of the sub-study is to assess if the co administration of apalutamide and relugolix is able to maintain castrate levels of testosterone.