Lutetium-177-prostate-specific membrane antigen ligand following radium-223 treatment in men with bone-metastatic castration-resistant prostate cancer: real-world clinical experience.

We analyzed real-world clinical outcomes of sequential alpha-/beta-emitter therapy for metastatic castration-resistant prostate cancer (mCRPC). Methods: We assessed safety and overall survival in 26 patients who received lutetium-177-prostate-specific membrane antigen ligand (177Lu-PSMA) following radium-223 in the ongoing non-interventional Radium-223 alpha Emitter Agent Safety Study in mCRPC popUlation for long-teRm Evaluation (REASSURE; NCT02141438). Results: Patients received radium-223 for a median 6 injections and subsequent 177Lu-PSMA for a median 3.5 months (≥4th therapy in 69%). The median time between radium-223 and 177Lu-PSMA treatment was 8 months (range 1-31). Grade 3 hematologic events occurred in 9/26 patients (during or after 177Lu-PSMA treatment in 5/9 patients; 8/9 patients had also received docetaxel). Median overall survival was 28.0 months from radium-223 start and 13.2 months from 177Lu-PSMA start. Conclusion: Although the small sample size precludes definitive conclusions, these preliminary data, especially 177Lu-PSMA treatment duration, suggest feasibility of 177Lu-PSMA use after radium-223 in this real-world setting.