Prostate cancer is currently the fifth leading cause of cancer deaths among men globally, with 1 million diagnosed per year and mortality burden of over 300,000 deaths. The hypothesis of study is addition of apalutamide to RT+ LHRHa provides superior efficacy in terms of PSMA-PET metastatic progression-free survival-ppMPFS. Apalutamide is a non-steroidal androgen receptor (AR) antagonist being developed for the treatment of prostate cancer. RT+LHRHa is a combination therapy, when administered concomitantly, in high-risk patients with BCR relapsing after RP, potentially leads to relevant delay in the metastatic progression of prostate cancer at an early stage of the disease, or even cure in some cases. Study consists of 2 cohorts (intervention and observational cohort). At screening, eligible participants will undergo prostate-specific membrane antigen-positron emission tomography (PSMA-PET), whole-body Tc-bone scan, computed tomography (CT). Interventional Cohort, consisting of PSMA-PET positive participants, will undergoes 3 phases: Treatment Phase, a Post-treatment Phase and a Post-PSMA-PET Progression Phase. After 6-month Treatment Phase, participants will be prospectively assessed in Post-treatment Phase until PSMA-PET-positive metastatic progression is confirmed. Observational cohort will run parallelly to interventional cohort. PSMA-PET negative, participants will be observed until time-point when number of events required for analysis of primary endpoint is reached in Interventional Cohort. This cohort provides an approach to document the selection of treatments and observation of interventions in a real-life clinical practice setting. The duration of the study is estimated to be approximately 7 years.
The main purpose of this study is to determine if the addition of apalutamide to radiotherapy (RT) plus luteinizing hormone-releasing hormone agonist (LHRHa) delays metastatic progression as assessed by prostate specific membrane antigen-positron emission tomography (PSMA-PET) or death compared with RT plus LHRHa alone.