Surgical Treatment With or Without Apalutamide in Subjects With High Risk Prostate Cancer Who Are Candidates for Radical Prostatectomy and Staged as Oligometastatic With PSMA-PET

This is a phase 2, open-label, randomized study of adjuvant treatment in subjects with high-risk prostate cancer who are candidates for RP with PLND based on M0 status at conventional imaging, but staged as oligometastatic with PSMA PET/CT (performed as routine practice, according to recent evidence on high-risk prostate cancer patients). Ninety-four subjects will receive apalutamide plus ADT or ADT alone after surgery. ADT is defined as medical castration (ie, gonadotropin-releasing hormone analogues \[GnRHa, agonist or antagonist\]). Subjects will be randomly assigned in a 1:1 ratio to receive apalutamide plus ADT or ADT alone. Patients randomized to receive ADT + apalutamide or ADT alone will begin their adjuvant treatment 4 weeks (28 to 32 days) after surgery. A first dosage of PSA and testosterone will be performed just before starting adjuvant therapy but not before 28 days from surgery. Subsequently, PSA and testosterone dosage and clinical visits will be performed after 3 months from surgery and every 3 months until completion of study. PSMA PET/CT scan will be performed yearly, or in case of PSA progression. The Posttreatment Follow-up Phase will begin after 18 months of ADT and will last for 6 months, until study completion. Afterwards, patients will continue their follow-up according to the best clinical practice.