RT Journal Article SR Electronic T1 German Multicenter Study Investigating 177Lu-PSMA-617 Radioligand Therapy in Advanced Prostate Cancer Patients JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 85 OP 90 DO 10.2967/jnumed.116.183194 VO 58 IS 1 A1 Kambiz Rahbar A1 Hojjat Ahmadzadehfar A1 Clemens Kratochwil A1 Uwe Haberkorn A1 Michael Schäfers A1 Markus Essler A1 Richard P. Baum A1 Harshad R. Kulkarni A1 Matthias Schmidt A1 Alexander Drzezga A1 Peter Bartenstein A1 Andreas Pfestroff A1 Markus Luster A1 Ulf Lützen A1 Marlies Marx A1 Vikas Prasad A1 Winfried Brenner A1 Alexander Heinzel A1 Felix M. Mottaghy A1 Juri Ruf A1 Philipp Tobias Meyer A1 Martin Heuschkel A1 Maria Eveslage A1 Martin Bögemann A1 Wolfgang Peter Fendler A1 Bernd Joachim Krause YR 2017 UL http://jnm.snmjournals.org/content/58/1/85.abstract AB 177Lu-labeled PSMA-617 is a promising new therapeutic agent for radioligand therapy (RLT) of patients with metastatic castration-resistant prostate cancer (mCRPC). Initiated by the German Society of Nuclear Medicine, a retrospective multicenter data analysis was started in 2015 to evaluate efficacy and safety of 177Lu-PSMA-617 in a large cohort of patients. Methods: One hundred forty-five patients (median age, 73 y; range, 43–88 y) with mCRPC were treated with 177Lu-PSMA-617 in 12 therapy centers between February 2014 and July 2015 with 1–4 therapy cycles and an activity range of 2–8 GBq per cycle. Toxicity was categorized by the common toxicity criteria for adverse events (version 4.0) on the basis of serial blood tests and the attending physician’s report. The primary endpoint for efficacy was biochemical response as defined by a prostate-specific antigen decline ≥ 50% from baseline to at least 2 wk after the start of RLT. Results: A total of 248 therapy cycles were performed in 145 patients. Data for biochemical response in 99 patients as well as data for physician-reported and laboratory-based toxicity in 145 and 121 patients, respectively, were available. The median follow-up was 16 wk (range, 2–30 wk). Nineteen patients died during the observation period. Grade 3–4 hematotoxicity occurred in 18 patients: 10%, 4%, and 3% of the patients experienced anemia, thrombocytopenia, and leukopenia, respectively. Xerostomia occurred in 8%. The overall biochemical response rate was 45% after all therapy cycles, whereas 40% of patients already responded after a single cycle. Elevated alkaline phosphatase and the presence of visceral metastases were negative predictors and the total number of therapy cycles positive predictors of biochemical response. Conclusion: The present retrospective multicenter study of 177Lu-PSMA-617 RLT demonstrates favorable safety and high efficacy exceeding those of other third-line systemic therapies in mCRPC patients. Future phase II/III studies are warranted to elucidate the survival benefit of this new therapy in patients with mCRPC.