LBA-25 RESIST-PC PHASE 2 TRIAL: 177LU-PSMA-617 RADIONUCLIDE THERAPY FOR METASTATIC CASTRATE-RESISTANT PROSTATE CANCER

INTRODUCTION AND OBJECTIVES:Introduction: This is an investigator-initiated open-label prospective bi-centric single-arm phase 2 clinical trial (NCT03042312) of 177Lu-PSMA-617 radionuclide therapy in patients with progressive metastatic castrate-resistant prostate cancer (mCRPC).METHODS:Methods: Patients with progressive mCRPC (biochemical, radiographic or clinical) after >=1 novel androgen axis drug (NAAD), either chemotherapy (CTX) naive or post-CTX, with sufficient bone marrow reserve and normal kidney function were eligible. All patients underwent a screening PSMA PET/CT to confirm target expression. Patients received up to 4 cycles of 177Lu-PSMA-617 every 8 ±1 weeks and were randomized into 2 treatment activities groups (6.0 or 7.4 GBq). Kidney dosimetry was performed for the first cycle. Efficacy was defined as serum PSA decline of 50% from baseline at 12 weeks and served as primary endpoint.RESULTS:Results: 64 patients (median PSA 75 ng/ml; range 0.5-2425) were included in the study. 20% were CTX n...