Apa/Enza-short Study: Shorter Treatment With Androgen Receptor Pathway Inhibitor in Patients With Low-volume Metastatic Castration-sensitive Prostate Cancer

Inclusion Criteria: * Male and ≥18 years of age * Capable of understanding and complying with protocol requirements and able to understand and sign the informed consent form * Histological diagnosis of prostate adenocarcinoma * Low volume de novo metastatic disease (M1a or M1b) defined as anything other than fitting the criteria for high-volume metastatic disease, e.g., four or more bone lesions with one or more lesions in any body structure beyond the spine or pelvis, or visceral disease (non-nodal). This has been assessed by either bone scan and computed tomography (CT), or PSMA-PET scan. Low-volume disease has subsequently been confirmed by the local (multidisciplinary) team after consideration of the available imaging results as per the standard imaging protocol for the site. * ADT initiated within 6 weeks prior to inclusion * Eastern Cooperative Oncology Group (ECOG) performance scale status of 0, 1 or 2 * Fit for treatment with apalutamide or enzalutamide according to treating physician Exclusion Criteria: * Pathological finding consistent with small cell, ductal or neuroendocrine carcinoma of the prostate * Other prior malignancy less than or equal to 5 years prior to randomization except for squamous or basal cell skin carcinoma or non-invasive superficial bladder cancer * History of seizures or medications known to lower seizure threshold * Any other prior treatment for prostate cancer other than ADT (e.g., other next generation anti-androgens or other CYP17 inhibitors, chemotherapy, immunotherapy, or radiopharmaceutical agents) * ADT started more than 6 weeks before inclusion