Radioligand Therapy with Lutetium 177-labeled PSMA – I&T for Metastatic Castration-Resistant Prostate Cancer: Clinical Experience with 100 Consecutive Patients

INTRODUCTION & OBJECTIVES: To report our clinical with 177 Lutetium- labeled prostate- specific membrane antigen-ligand (177 Lu-PSMA-I&T) for systemic radioligand therapy in 100 consecutive patients with metastatic castration- resistant prostate cancer (mCRPC).

MATERIALS & METHODS: All patients were treated under a review board-approved compassionate use protocol.  Eligibility criteria for 177 Lu-PSMA-I&T therapy included previous treatment with abiraterone or enzalutamide, previous taxane-based chemotherapy or ineligibility to taxanes as well as positive 68 Ga-PSMA tracer uptake of metastases in prior PET-scan. Intravenous treatment with 177 Lu-PSMA-I&T was given 6- to 8-weekly with an activity of 7.4GBq up to 6 cycles in patients without clinical or radiographic progression. We report prostate-specific antigen (PSA) decline, PSA progression-free survival (PSA-PFS), clinical progression -free survival (cPFS) and overall survival (OS) as well as toxicity.

RESULTS: At baseline, median age was 72 years (range 46-85) and median PSA level was 164 ng/ml (range 0-6178). Bone, lymph node and visceral metastases were present in 94, 85 and 33 patients, respectively. The median number of previous treatment regimens for mCRPC was 3 (range 1-6) and 84 patients were pretreated with chemotherapy. At the time of evaluation, 286 cycles with 177 Lu-PSMA-I&T were applied (median 2 cycles per patient, range 1-6), while treatment was still ongoing in 27 patient. Overall, 4 and 6 cycles were applied in 33 and 15 patients, respectively. PSA decline ≥ 30%, ≥ 50%, and ≥90% was achieved in 40,32 and 9 patients, respectively. Median PSA-PFS was 3.4 months (95%CL 2.7-4.0), median cPFS was 4.1 months (95% CL 2.5-5.7) and median OS was 12.2 months (95%CL 8.8 15.7). Treatment-emergent hematologic grade 3/4 toxicities were anemia in 7, thrombocytopenia in 5 and neutropenia in 4 patients. Grade 3/4 non-hematologic toxicities were not observed. The main non-hematologic grade 1/2 toxicities were dry mouth in 18, fatigue in 16 and loss of appetite in 9 of patients.

CONCLUSIONS: Radioligand therapy with 177 Lu-PSMA I&T appears to be safe and active in late-stage mCRPC.

European Urology Supplements, vol 17 , issue 2. 16 March 2018 [Epub]

M. Heck1, S. Schwaiger1, K. Knorr2, T. Maurer1, F. Janssen1, C. D’Alessandria2,  H-J. Wester3, J. Gschwend1, M. Schwaiger2, R. Tauber1, M. Elber2

1. Rechts der Isar University Hospital, Technical University of Munich, Dept. of Urology, Munich, Germany
2. Rechts der Isar University Hospital, Technical University of Munich, Dept. of Nuclear Medicine, Munich, Germany
3. Technical University of Munich, Dept. of Pharmaceutical Radiochemistry, Gauting, Germany

Eur Urol Suppl 2018; 17(2); e874: DOI: