This study investigates cell-free DNA in patients with metastatic castration-resistant prostate cancer. Metastatic castration-resistant prostate cancer is a type of prostate cancer that continues to grow and spread even when the amount of testosterone in the body is reduced to very low levels. The study aims to understand how cell-free DNA, which are small pieces of DNA found in the blood, can be used to track the cancer's response to treatment.
Participants will receive therapy with either an investigational medication or a placebo. The study will involve regular blood tests to measure cell-free DNA levels. A placebo is an inactive substance that looks like the investigational medicine but does not contain any medicine.
- Who can participate: Men aged 18 and older with metastatic castration-resistant prostate cancer who are eligible for treatment with abiraterone or enzalutamide may participate.
- Study details: Participants will be assigned to receive either an investigational medication or a placebo. Blood samples will be collected to measure cell-free DNA levels. A placebo is an inactive substance that looks like the investigational medicine but does not contain any medicine.

