I know that several patients are looking for a non-randomized trial in the US. This one relies on the theory that the immunotherapy response may be improved by adding a radiotherapy. This theory is discussed here:
It is for men with mCRPC who are PSMA-avid (at least 3 PSMA-avid mets) and who have tried Zytiga, Xtandi or Erleada. They allow previous chemo only if it was used while they were still hormone sensitive. There is a single Lu-177-PSMA-617 infusion and patients will get the Keytruda starting 3 weeks before, at the start of, or 3 weeks after Lu-177-PSMA-617. Keytruda may continue for up to 3 years if it seems to be working. They begin recruiting this month. Here are the details:
Also, there is no charge for the Lu-PSMA, Ga-PSMA, or Keytruda. Travel and accommodations are not reimbursed.