Castrate Resistant Prostate Cancer Enhertu Therapy

This study is testing trastuzumab deruxtecan (Enhertu) — a targeted therapy that delivers chemotherapy directly into cancer cells — for men with advanced prostate cancer that has stopped responding to hormone therapy (metastatic castrate-resistant prostate cancer, or mCRPC). Researchers want to see if Enhertu, which is already approved for some breast and lung cancers, can help prostate cancer patients. **You may be eligible if...** - You have prostate cancer confirmed by biopsy that is castrate-resistant and has spread to other parts of the body - You have progressed on hormone-blocking treatments (like enzalutamide or abiraterone) - You are maintaining low testosterone levels through ongoing treatment - You have a tumor tissue sample available for HER2 testing - Your heart, liver, kidney, and blood counts are in acceptable range - Your life expectancy is at least 6 months **You may NOT be eligible if...** - You have a history of interstitial lung disease or pneumonitis requiring steroids - You have significant heart or coronary artery disease - You have previously received a HER2-targeted therapy Talk to your doctor to see if this trial is right for you.