Safety and Survival Outcomes of Lutetium-177–Prostate-Specific Membrane Antigen Therapy in Patients with Metastatic Castration-Resistant Prostate Cancer with prior Radium-223 treatment: The RALU Study

Abstract

The RAdium LUtetium (RALU) study evaluated the feasibility of sequential alpha and beta emitter use in patients with bone-predominant metastatic castration-resistant prostate cancer. Methods: This pre-planned, interim, retrospective analysis investigated safety and survival outcomes with lutetium-177-PSMA (¹⁷⁷Lu-PSMA) in patients treated with prior radium-223 (²²³Ra). Results: Forty-nine patients were evaluated. Patients received a median of 6 ²²³Ra injections; 59% of patients received ≥4 ¹⁷⁷Lu-PSMA cycles. Most (69%) patients received ≥4 life-prolonging therapies before ¹⁷⁷Lu-PSMA. Common Terminology Criteria for Adverse Events Grade 3–4 treatment-emergent adverse events during ¹⁷⁷Lu-PSMA therapy and a 30-day follow-up period included anemia (18%) and thrombocytopenia (2%). Median overall survival was 12.6 (95% CI 8.8–16.1) and 31.4 months (95% CI 25.7–37.6) from starting ¹⁷⁷Lu-PSMA or ²²³Ra, respectively. Conclusions: ¹⁷⁷Lu-PSMA treatment was well tolerated in patients who had received prior ²²³Ra. ²²³Ra use before ¹⁷⁷Lu-PSMA is feasible and can be considered for future assessment of optimal treatment sequence.