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 jnumed.116.183194 DO 10.2967/jnumed.116.183194 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 Kulkarani A1 Matthias Schmidt A1 Peter Bartenstein A1 Andreas Pfestroff A1 Ulf Lützen A1 Marlies Marx A1 Vikas Prasad A1 Winfried Brenner A1 Alexander Heinzel 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 2016 UL http://jnm.snmjournals.org/content/early/2016/10/19/jnumed.116.183194.abstract AB 177Lutetium 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: 145 patients (median age 73 years, range 43-88) with mCRPC were treated with 177Lu-PSMA-617 in 12 therapy centres between February 2014 and July 2015 with one to four therapy cycles and an activity range of 2 to 8 GBq per cycle. Toxicity was categorized by the common toxicity criteria for adverse events (CTCAE 4.0) based on serial blood tests and the attending physician’s report. Primary endpoint for efficacy was biochemical response as defined by a PSA decline ≥ 50% from baseline to at least two weeks after start of RLT. Results: A total of 248 therapy cycles were performed in 145 patients. Data for biochemical response were available in 99 patients and data for physician-reported/lab-based toxicity in 145/121 patients. The median follow-up was 16 weeks (range 2-30 weeks). Nineteen patients died during the observation period. Grade 3 to 4 hematotoxicity occurred in 18 patients: 10%, 4% and 3% of the patients experienced anemia, thrombocytopenia and leukopenia, respectively. Xerostomia occurred in 8%. Overall biochemical response rate was 45% following all therapy cycles, while 40% of patients already responded after a single cycle. Elevated alkaline phosphatase and 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.