The study is looking at a new treatment for mCRPC (metastatic castration-resistant prostate cancer), which is a type of prostate cancer that has spread to other parts of the body and doesn’t respond to treatments that lower testosterone. Participants will be patients who have a positive PSMA scan, a special type of scan that shows prostate cancer activity. The study will test if ONC-392, when used with lutetium Lu 177 vipivotide tetraxetan, is safe and helps patients by slowing down cancer growth.

Participants in the study will be randomly placed into different groups. Some will receive ONC-392 through an IV (intravenous) and lutetium Lu 177 vipivotide tetraxetan, while others will receive the standard treatment. The study lasts up to one year, with visits and treatments that may vary depending on the group.

• The study involves multiple visits and cycles of treatment over about a year.
• Participants must meet specific health criteria to join, like having a positive PSMA scan.
• There are potential risks and side effects from the treatments, which will be explained during the consent process.