This study is testing a new medicine called Lutetium (177Lu) rhPSMA-10.1 for men with a type of prostate cancer that has spread and doesn't respond to hormone treatments. This study has two parts: Phase 1 to find a safe dose and check safety, and Phase 2 to see how well it works. Participants need to have specific markers (called PSMA) that show up on certain scans. The study is for men over 18 who have certain levels of testosterone and have tried other treatments. Some can't join if they have other serious health problems or specific conditions like certain bone scan results.

• The study includes men with specific prostate cancer markers.
• Participants should have tried other treatments but not too many rounds of chemotherapy.
• The study has two phases to test safety and effectiveness of the treatment.