The goal of this phase 3 clinical trial is to determine the clinical effectiveness and cost effectiveness of using lower doses of Androgen Receptor Pathway Inhibitors (ARPI) to treat patients with prostate cancer that has spread (metastasized). The main questions it aims to answer are: 1. if overall survival for reduced dose ARPI is not worse than standard dose ARPI when treating patients with metastatic prostate cancer, and 2. that fatigue (extreme exhaustion) and not stopping ARPI permanently (due to adverse effects) are better than average with the reduced dose. Participants will: * Be randomised to take full dose (100%) of ARPI or half dose (50%) of ARPI. * Receive standard of care ADT. * Be on treatment for approximately 3 years according to standard of care. * Have clinic assessments and visits in clinic or remotely, as per their treating hospital's standard routine local practice in line with standard of care. Additional visits are not expected. * Complete quality of life questionnaires at week 0 (pre-treatment) and weeks 4, 16, 32, 48 and 64. * Keep a diary of their symptoms. Translational research samples will be collected as follows: * Blood samples at week 0 (pre-treatment) and weeks 24, 32, 48 and at disease progression. * Urine samples at week 0 (pre-treatment) and week 24 and at disease progression. * FFPE Tumour: Routinely collected diagnostic blocks. The duration of follow-up is approximately 3 years after the last patient is recruited (minimum follow-up is 3 years; maximum follow-up is approximately 6 years for the the first patient recruited) and the trial is expected to complete August 2032 (Last Patient Last Visit).
Age range
18 Years
Sex
MALE
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Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
Overall survival (primary efficacy)
Timeframe: From randomisation up to 6 years (or date last known to be alive) or date of death, whichever occurs first.
The percentage of patients who permanently discontinue ARPI due to adverse events
Timeframe: From start of treatment to permanent discontinuation of trial treatment up to 3 years after last patient is recruited (approximately 6 years for the first patient recruited).
Fatigue assessed using the EORTC 12-point fatigue scale (primary toxicity)
Timeframe: Pre-treatment, Weeks 16, 32, 48 and 64 from start of treatment.