This study examines a new medicine, ARX517, for treating metastatic prostate cancer, which means the cancer has spread to other parts of the body. The study is in Phase 1, which is the first time doctors are testing ARX517 in humans to check its safety and how well it works. Some patients will receive ARX517 alone, while others will also take androgen receptor pathway inhibitors (ARPIs). Participants must be males, aged 18 or older, with confirmed prostate cancer. They should have received some treatments before and show signs that their cancer is progressing. The study requires good blood counts and at least one specific type of cancer lesion.

• The study lasts for several months with regular check-ups.
• No recent chemotherapy or certain other treatments before joining.
• Participants should not have major health issues like brain problems or severe lung diseases.