Re-treatment With 177Lu-PSMA-617 for the Treatment of Metastatic Castration-Resistant Prostate Cancer, RE-LuPSMA Trial

Inclusion Criteria: * Patients must have mCRPC * Patients must have received at least one regimen of chemotherapy for mCRPC * Patients must have received at least one androgen receptor signaling inhibitor (ARSI) * Patients must have previously completed at least 4 cycles of 177Lu-PSMA-617 therapy * Patients must have had a favorable response to the first regimen of 177Lu-PSMA-617 therapy defined as: * PSA decline of ≥ 50% at any time during the first regimen of 177Lu-PSMA-617 therapy AND * No new prostate cancer therapy within two months of completing the first regimen of 177Lu-PSMA-617 therapy (first-generation androgen deprivation therapy \[ADT\] is allowed). Concomitant prostate cancer therapy that was administrated during the first regimen of 177Lu-PSMA-617 therapy and continued afterwards is allowed * Patients must have had a PSA increase after the first regimen of 177Lu-PSMA-617 therapy, confirmed by a second measurement ≥ 3 weeks apart * Patients must meet PSMA PET/CT VISION criteria. PSMA PET/CT must have been completed within 8 weeks of the planned first cycle of re-challenge 177Lu-PSMA-617 therapy and at least 6 weeks after completion of the first regimen of 177Lu-PSMA-617 therapy * White blood cells \> 2,500 cells/µL * Absolute neutrophil count \> 1,500 cells/µL * Hemoglobin \> 9.0 g/dL * Platelets \> 100,000 cells/µL * Patients must have the ability to understand and sign an approved informed consent form (ICF) and comply with all protocol requirements Exclusion Criteria: * Patient received new prostate cancer therapy within two months of completing the first regimen of 177Lu-PSMA-617 therapy (first-generation ADT (adenosine triphosphate) is allowed). This can include apalutamide, enzalutamide, abiraterone, chemotherapy, immunotherapy, radionuclide therapy, PARP inhibitor, or any biological therapy. Concomitant prostate cancer therapy that was administrated during the first regimen of 177Lu-PSMA-617 therapy and continued afterwards is allowed * Patient received myelosuppressive therapy (including docetaxel, cabazitaxel, 223Ra, and 153Sm) or other radionuclide therapy within the last 6 weeks * Patient with creatinine clearance \< 50 mL/min