(177)Lu-Prostate-Specific Membrane Antigen Ligand After (223)Ra Treatment in Men with Bone-Metastatic Castration-Resistant Prostate Cancer: Real-World Clinical Experience

We analyzed real-world clinical outcomes of sequential α-/β-emitter therapy for metastatic castration-resistant prostate cancer (mCRPC). Methods: We assessed safety and overall survival in 26 patients who received (177)Lu-prostate-specific membrane antigen ligand ((177)Lu-PSMA) after (223)Ra in the ongoing noninterventional REASSURE study ((223)Ra α-Emitter Agent in Nonintervention Safety Study in mCRPC Population for Long-Term Evaluation; NCT02141438). Results: Patients received (223)Ra for a median of 6 injections and subsequent (177)Lu-PSMA for a median of 3.5 mo (≥ the fourth therapy in 69%). The median time between (223)Ra and (177)Lu-PSMA treatment was 8 mo (range, 1–31 mo). Grade 3 hematologic events occurred in 9 of 26 patients (during or after (177)Lu-PSMA treatment in 5/9 patients; 8/9 patients had also received docetaxel). Median overall survival was 28.0 mo from the (223)Ra start and 13.2 mo from the (177)Lu-PSMA start. Conclusion: Although the small sample size precludes definitive conclusions, these preliminary data, especially the (177)Lu-PSMA treatment duration, suggest that the use of (177)Lu-PSMA after (223)Ra is feasible in this real-world setting.