Bipolar Androgen Therapy + Carboplatin in mCRPC

This trial is studying a combination of bipolar androgen therapy (alternating very high and very low testosterone doses) plus carboplatin (a chemotherapy drug) in men with advanced prostate cancer that no longer responds to standard hormone therapy and has a specific DNA repair defect. **You may be eligible if...** - You are a male 18 or older diagnosed with prostate cancer - Your cancer has a confirmed defect in DNA repair (called HRD — homologous recombination deficiency) - Your PSA (prostate-specific antigen) blood levels are rising despite having very low testosterone from hormone therapy - Your testosterone level is very low (castrate levels) and you are currently on hormone therapy or have had surgical castration for at least 1 year - Your blood counts, liver, kidney, and heart function are within acceptable ranges **You may NOT be eligible if...** - You have pain from your prostate cancer that requires opioid pain medications - Your cancer is actively progressing in ways that make this approach unsafe - You have contraindications to either treatment drug - Your organ function is outside the required ranges Talk to your doctor to see if this trial is right for you.