PT - JOURNAL ARTICLE AU - Rahbar, Kambiz AU - Essler, Markus AU - Eiber, Matthias AU - la Fougère, Christian AU - Prasad, Vikas AU - Fendler, Wolfgang P. AU - Rassek, Philipp AU - Hasa, Ergela AU - Dittmann, Helmut AU - Bundschuh, Ralph A. AU - Pabst, Kim M. AU - Kurtinecz, Milena AU - Schmall, Anja AU - Verholen, Frank AU - Sartor, Oliver TI - <sup>177</sup>Lu-Prostate-Specific Membrane Antigen Therapy in Patients with Metastatic Castration-Resistant Prostate Cancer and Prior <sup>223</sup>Ra (RALU Study) AID - 10.2967/jnumed.123.266125 DP - 2023 Dec 01 TA - Journal of Nuclear Medicine PG - 1925--1931 VI - 64 IP - 12 4099 - http://jnm.snmjournals.org/content/64/12/1925.short 4100 - http://jnm.snmjournals.org/content/64/12/1925.full SO - J Nucl Med2023 Dec 01; 64 AB - 223Ra-dichloride (223Ra) and 177Lu-prostate-specific membrane antigen (PSMA) are approved treatments for metastatic castration-resistant prostate cancer (mCRPC). The safety and effectiveness of sequential use of 223Ra and 177Lu-PSMA in patients with mCRPC are not well described. This study aimed to evaluate 177Lu-PSMA safety and efficacy in patients with mCRPC previously treated with 223Ra. Methods: The radium→lutetium (RALU) study was a multicenter, retrospective, medical chart review. Participants had received at least 1 223Ra dose and, in any subsequent therapy line, at least 1 177Lu-PSMA dose. Primary endpoints included the incidence of adverse events (AEs), serious AEs, grade 3–4 hematologic AEs, and abnormal laboratory values. Secondary endpoints included overall survival, time to next treatment/death, and change from baseline in serum prostate-specific antigen and alkaline phosphatase levels. Results: Data were from 133 patients. Before 177Lu-PSMA therapy, 56% (75/133) of patients received at least 4 life-prolonging therapies; all patients received 223Ra (73% received 5–6 injections). Overall, 27% (36/133) of patients received at least 5 177Lu-PSMA infusions. Any-grade treatment-emergent AEs were reported in 79% (105/133) of patients and serious AEs in 30% (40/133). The most frequent grade 3–4 laboratory abnormalities were anemia (30%, 40/133) and thrombocytopenia (13%, 17/133). Median overall survival was 13.2 mo (95% CI, 10.5–15.6 mo) from the start of 177Lu-PSMA. Conclusion: In this real-world setting, 223Ra followed by 177Lu-PSMA therapy in heavily pretreated patients with mCRPC was clinically feasible, with no indication of impairment of 177Lu-PSMA safety or effectiveness.