177Lu-PSMA radioligand therapy of predominant lymph node metastatic prostate cancer

// Finn Edler von Eyben 1, * , Aviral Singh 2, * , Jingjing Zhang 2 , Karin Nipsch 2 , Danielle Meyrick 3 , Nat Lenzo 3, 4 , Kalevi Kairemo 5 , Timo Joensuu 5 , Irene Virgolini 6 , Cigdem Soydal 7 , Harshad R. Kulkarni 2, # and Richard Paul Baum 2, # 1 Center of Tobacco Control Research, Odense, Denmark 2 Theranostics Center for Molecular Radiotherapy and Molecular Imaging, Zentralklinik Bad Berka, Bad Berka, Germany 3 GenesisCare Oncology, Theranostics, East Freemantle, Australia 4 School of Medicine and Pharmacology, University of Western Australia, Nedlands, Australia 5 Docrates Cancer Center, Helsinki, Finland 6 Department of Nuclear Medicine, University Hospital in Innsbruck, Innsbruck, Austria 7 Department of Nuclear Medicine, University of Ankara, Faculty of Medicine, Universitesi Tip Faultesi Sikkiye, Ankara, Turkey * These authors are first authors # These authors are last senior authors Correspondence to: Finn Edler von Eyben, email: finn113edler@mail.tele.dk Keywords: metastatic prostate cancer; lutetium prostate specific membrane antigen radiolabeled radionuclide therapy; PSA response; relapse treatment; overall survival Received: December 27, 2018 Accepted: March 04, 2019 Published: March 29, 2019 ABSTRACT 177 Lu-PSMA radioligand therapy (LuPRLT) is mainly used for patients with metastatic castration-resistant prostate cancer who are resistant to established drugs. This study describes LuPRLT, either LuPSMA I&T or LuPSMA RLT-617, for 45 patients with predominant lymph node metastatic prostate cancer (LNM PC). Thirty-five patients had LNM and ten patients had LNM and one or two bone metastases. Before LuPRLT, the patients had prostate specific antigen (PSA) of median 18 μg/l (interquartile range (IQR): 3.3–39). LuPRLT was given with a cumulative injected 177 Lu activity of median 14.5 GBq (IQR: 12.2–20.4). Maximum percentage decline of PSA was median 92% (IQR: 70–99). Thirty-five patients with only LNM had a better overall survival (OS) than ten patients with LNM and one or two bone metastases. Thirty-three docetaxel-naïve patients had a longer PSMA PET/CT progression-free survival than twelve patients who were resistant to docetaxel. Twenty-two patients who received LuPRLT with a cumulative injected 177 Lu activity ≥ 14.8 GBq had a better PSMA PET/CT progression-free survival than 23 patients who received LuPRLT with a lower cumulative injected 177 Lu activity. Seventeen patients with relapse after LuPRLT who received rechallenge LuPRLT or ActPRLT had a better OS than five patients who received other forms for relapse treatment. LuPRLT gave mild and transitory adverse effects. The findings of the present study suggest that LuPRLT of patients with LNM may be effective and safe. The promising results motivate randomized phase II trials to further quantify the impact of LuPRLT as treatment of patients with LNM.