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Hanu AR, Atanackovic J, Boyd C, Johnston EM, Waker AJ. Characterization and mapping of the neutron fields around Bruce Power's 177Lu isotope production system. Appl Radiat Isot 2024; 208:111284. [PMID: 38492278 DOI: 10.1016/j.apradiso.2024.111284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 02/14/2024] [Accepted: 03/09/2024] [Indexed: 03/18/2024]
Abstract
Bruce Power operates a first-of-its-kind isotope production system (IPS) that enables continuous production of 177Lu within Canada Deuterium Uranium (CANDU) commercial power reactors. Located on the reactivity mechanisms deck of Unit 7, just outside of reactor containment but in close proximity to the primary heat transport (PHT) pumps, this facility offers unique advantages for 177Lu production. However, employees working in this area encounter a radiation hazard which consists primarily of photoneutrons. These originate from the base of the PHT pumps and are only present when the reactor is operating. This study evaluates neutron exposure at Bruce Power's IPS by using a nested neutron spectrometer (NNS) to determine the neutron energy spectra and absolute dosimetric quantities such as the ambient dose equivalent, H*(10). The results from the NNS are then compared to surveys performed by a portable neutron rem meter (Model NP-2 by Nuclear Research Corporation), routinely used by Bruce Power staff for workplace monitoring. While the Model NP-2 generally showed consistent results across locations, a 50% dose correction factor was identified when operators were harvesting 177Lu from the IPS. This finding highlights an opportunity to reduce the neutron dose that is assigned to operators when producing 177Lu.
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Affiliation(s)
- Andrei R Hanu
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada; Bruce Power, Tiverton, Ontario, Canada.
| | - Jovica Atanackovic
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada; Ontario Power Generation, Whitby, Ontario, Canada
| | - Craige Boyd
- Department of Energy and Nuclear Engineering, Ontario Tech University, Oshawa, Ontario, Canada
| | - Eric M Johnston
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada; Nuclear Innovation Institute, Port Elgin, Ontario, Canada
| | - Anthony J Waker
- Department of Energy and Nuclear Engineering, Ontario Tech University, Oshawa, Ontario, Canada
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2
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Mo C, Sun P, Liang H, Chen Z, Wang M, Fu L, Huang S, Tang G. Synthesis and preclinical evaluation of a novel probe [ 18F]AlF-NOTA-IPB-GPC3P for PET imaging of GPC3 positive tumor. Bioorg Chem 2024; 147:107352. [PMID: 38640719 DOI: 10.1016/j.bioorg.2024.107352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Revised: 03/23/2024] [Accepted: 04/05/2024] [Indexed: 04/21/2024]
Abstract
Glypican-3 (GPC3) is markedly overexpressed in hepatocellular carcinoma (HCC) and not expressed in normal liver tissues. In this study, a novel peptide PET imaging agent ([18F]AlF-NOTA-IPB-GPC3P) was developed to target GPC3 expressed in tumors. The overall radiochemical yield of [18F]AlF-NOTA-IPB-GPC3P was 10-15 %, and its lipophilicity, expressed as the logD value at a pH of 7.4, was -1.18 ± 0.06 (n = 3). Compared to the previously reported tracer [18F]AlF-GP2633, [18F]AlF-NOTA-IPB-GPC3P exhibited higher cellular uptake (15.13 vs 5.96) and internalized rate (80.63 % vs 35.93 %) in Huh7 cells at 120 min. Micro-PET/CT and biodistribution studies further demonstrated that [18F]AlF-NOTA-IPB-GPC3P exhibited significantly increased tumor uptake and prolonged tumor residence in Huh7 tumors compared to [18F]AlF-GP2633 (4.66 ± 0.22 % ID/g vs 0.72 ± 0.09 % ID/g at 60 min, p < 0.001; 5.05 ± 0.23 % ID/g vs 0.35 ± 0.08 % ID/g at 120 min, p < 0.001, respectively). Furthermore, the tumor-to-organ ratios of [18F]AlF-NOTA-IPB-GPC3P surpassed those of [18F]AlF-GP2633. Our results support the utilization of [18F]AlF-NOTA-IPB-GPC3P as a PET imaging agent targeting the GPC3 receptor for tumor detection.
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Affiliation(s)
- Chunwei Mo
- Department of Nuclear Medicine, Nanfang Hospital, Southern Medical University, GDMPA Key Laboratory for Quality Control and Evaluation of Radiopharmaceuticals, Guangzhou, Guangdong Province 510515, China
| | - Penghui Sun
- Department of Nuclear Medicine, Nanfang Hospital, Southern Medical University, GDMPA Key Laboratory for Quality Control and Evaluation of Radiopharmaceuticals, Guangzhou, Guangdong Province 510515, China
| | - Haoran Liang
- Department of Nuclear Medicine, Nanfang Hospital, Southern Medical University, GDMPA Key Laboratory for Quality Control and Evaluation of Radiopharmaceuticals, Guangzhou, Guangdong Province 510515, China
| | - Zihao Chen
- Department of Nuclear Medicine, Nanfang Hospital, Southern Medical University, GDMPA Key Laboratory for Quality Control and Evaluation of Radiopharmaceuticals, Guangzhou, Guangdong Province 510515, China
| | - Meng Wang
- Department of Nuclear Medicine, Nanfang Hospital, Southern Medical University, GDMPA Key Laboratory for Quality Control and Evaluation of Radiopharmaceuticals, Guangzhou, Guangdong Province 510515, China
| | - Lilan Fu
- Department of Nuclear Medicine, Nanfang Hospital, Southern Medical University, GDMPA Key Laboratory for Quality Control and Evaluation of Radiopharmaceuticals, Guangzhou, Guangdong Province 510515, China
| | - Shun Huang
- Department of Nuclear Medicine, The Tenth Affiliated Hospital, Southern Medical University (Dongguan People's Hospital), Dongguan 523059, China.
| | - Ganghua Tang
- Department of Nuclear Medicine, Nanfang Hospital, Southern Medical University, GDMPA Key Laboratory for Quality Control and Evaluation of Radiopharmaceuticals, Guangzhou, Guangdong Province 510515, China.
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de Roode KE, Joosten L, Behe M. Towards the Magic Radioactive Bullet: Improving Targeted Radionuclide Therapy by Reducing the Renal Retention of Radioligands. Pharmaceuticals (Basel) 2024; 17:256. [PMID: 38399470 PMCID: PMC10892921 DOI: 10.3390/ph17020256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 02/07/2024] [Accepted: 02/09/2024] [Indexed: 02/25/2024] Open
Abstract
Targeted radionuclide therapy (TRT) is an emerging field and has the potential to become a major pillar in effective cancer treatment. Several pharmaceuticals are already in routine use for treating cancer, and there is still a high potential for new compounds for this application. But, a major issue for many radiolabeled low-to-moderate-molecular-weight molecules is their clearance via the kidneys and their subsequent reuptake. High renal accumulation of radioactive compounds may lead to nephrotoxicity, and therefore, the kidneys are often the dose-limiting organs in TRT with these radioligands. Over the years, different strategies have been developed aiming for reduced kidney retention and enhanced therapeutic efficacy of radioligands. In this review, we will give an overview of the efforts and achievements of the used strategies, with focus on the therapeutic potential of low-to-moderate-molecular-weight molecules. Among the strategies discussed here is coadministration of compounds that compete for binding to the endocytic receptors in the proximal tubuli. In addition, the influence of altering the molecular design of radiolabeled ligands on pharmacokinetics is discussed, which includes changes in their physicochemical properties and implementation of cleavable linkers or albumin-binding moieties. Furthermore, we discuss the influence of chelator and radionuclide choice on reabsorption of radioligands by the kidneys.
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Affiliation(s)
- Kim E. de Roode
- Department of Medical Imaging, Nuclear Medicine, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands;
- Tagworks Pharmaceuticals, Toernooiveld 1, 6525 ED Nijmegen, The Netherlands
| | - Lieke Joosten
- Department of Medical Imaging, Nuclear Medicine, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands;
| | - Martin Behe
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institut, 5232 Villigen, Switzerland
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Ha S, O JH, Park C, Boo SH, Yoo IR, Moon HW, Chi DY, Lee JY. Dosimetric Analysis of a Phase I Study of PSMA-Targeting Radiopharmaceutical Therapy With [ 177Lu]Ludotadipep in Patients With Metastatic Castration-Resistant Prostate Cancer. Korean J Radiol 2024; 25:179-188. [PMID: 38288897 PMCID: PMC10831299 DOI: 10.3348/kjr.2023.0656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 10/30/2023] [Accepted: 11/17/2023] [Indexed: 02/01/2024] Open
Abstract
OBJECTIVE 177Lutetium [Lu] Ludotadipep is a novel prostate-specific membrane antigen targeting therapeutic agent with an albumin motif added to increase uptake in the tumors. We assessed the biodistribution and dosimetry of [177Lu]Ludotadipep in patients with metastatic castration-resistant prostate cancer (mCRPC). MATERIALS AND METHODS Data from 25 patients (median age, 73 years; range, 60-90) with mCRPC from a phase I study with activity escalation design of single administration of [177Lu]Ludotadipep (1.85, 2.78, 3.70, 4.63, and 5.55 GBq) were assessed. Activity in the salivary glands, lungs, liver, kidneys, and spleen was estimated from whole-body scan and abdominal SPECT/CT images acquired at 2, 24, 48, 72, and 168 h after administration of [177Lu]Ludotadipep. Red marrow activity was calculated from blood samples obtained at 3, 10, 30, 60, and 180 min, and at 24, 48, and 72 h after administration. Organ- and tumor-based absorbed dose calculations were performed using IDAC-Dose 2.1. RESULTS Absorbed dose coefficient (mean ± standard deviation) of normal organs was 1.17 ± 0.81 Gy/GBq for salivary glands, 0.05 ± 0.02 Gy/GBq for lungs, 0.14 ± 0.06 Gy/GBq for liver, 0.77 ± 0.28 Gy/GBq for kidneys, 0.12 ± 0.06 Gy/GBq for spleen, and 0.07 ± 0.02 Gy/GBq for red marrow. The absorbed dose coefficient of the tumors was 10.43 ± 7.77 Gy/GBq. CONCLUSION [177Lu]Ludotadipep is expected to be safe at the dose of 3.7 GBq times 6 cycles planned for a phase II clinical trial with kidneys and bone marrow being the critical organs, and shows a high tumor absorbed dose.
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Affiliation(s)
- Seunggyun Ha
- Division of Nuclear Medicine, Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Joo Hyun O
- Division of Nuclear Medicine, Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
| | - Chansoo Park
- Research Institute of Labeling, FutureChem Co., Ltd., Seoul, Republic of Korea
| | - Sun Ha Boo
- Division of Nuclear Medicine, Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Ie Ryung Yoo
- Division of Nuclear Medicine, Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Hyong Woo Moon
- Department of Urology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Dae Yoon Chi
- Research Institute of Labeling, FutureChem Co., Ltd., Seoul, Republic of Korea
| | - Ji Youl Lee
- Department of Urology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
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Morgan KA, Rudd SE, Noor A, Donnelly PS. Theranostic Nuclear Medicine with Gallium-68, Lutetium-177, Copper-64/67, Actinium-225, and Lead-212/203 Radionuclides. Chem Rev 2023; 123:12004-12035. [PMID: 37796539 DOI: 10.1021/acs.chemrev.3c00456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/06/2023]
Abstract
Molecular changes in malignant tissue can lead to an increase in the expression levels of various proteins or receptors that can be used to target the disease. In oncology, diagnostic imaging and radiotherapy of tumors is possible by attaching an appropriate radionuclide to molecules that selectively bind to these target proteins. The term "theranostics" describes the use of a diagnostic tool to predict the efficacy of a therapeutic option. Molecules radiolabeled with γ-emitting or β+-emitting radionuclides can be used for diagnostic imaging using single photon emission computed tomography or positron emission tomography. Radionuclide therapy of disease sites is possible with either α-, β-, or Auger-emitting radionuclides that induce irreversible damage to DNA. This Focus Review centers on the chemistry of theranostic approaches using metal radionuclides for imaging and therapy. The use of tracers that contain β+-emitting gallium-68 and β-emitting lutetium-177 will be discussed in the context of agents in clinical use for the diagnostic imaging and therapy of neuroendocrine tumors and prostate cancer. A particular emphasis is then placed on the chemistry involved in the development of theranostic approaches that use copper-64 for imaging and copper-67 for therapy with functionalized sarcophagine cage amine ligands. Targeted therapy with radionuclides that emit α particles has potential to be of particular use in late-stage disease where there are limited options, and the role of actinium-225 and lead-212 in this area is also discussed. Finally, we highlight the challenges that impede further adoption of radiotheranostic concepts while highlighting exciting opportunities and prospects.
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Affiliation(s)
- Katherine A Morgan
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Melbourne 3010, Australia
| | - Stacey E Rudd
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Melbourne 3010, Australia
| | - Asif Noor
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Melbourne 3010, Australia
| | - Paul S Donnelly
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Melbourne 3010, Australia
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6
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Alati S, Singh R, Pomper MG, Rowe SP, Banerjee SR. Preclinical Development in Radiopharmaceutical Therapy for Prostate Cancer. Semin Nucl Med 2023; 53:663-686. [PMID: 37468417 DOI: 10.1053/j.semnuclmed.2023.06.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 06/19/2023] [Accepted: 06/21/2023] [Indexed: 07/21/2023]
Abstract
Prostate cancer is a leading cause of cancer death in men worldwide. Among the various treatment options, radiopharmaceutical therapy has shown notable success in metastatic, castration-resistant disease. Radiopharmaceutical therapy is a systemic approach that delivers cytotoxic radiation doses precisely to the malignant tumors and/or tumor microenvironment. Therapeutic radiopharmaceuticals are composed of a therapeutic radionuclide and a high-affinity, tumor-targeting carrier molecule. Therapeutic radionuclides used in preclinical prostate cancer studies are primarily α-, β--, or Auger-electron-emitting radiometals or radiohalogens. Monoclonal antibodies, antibody-derived fragments, peptides, and small molecules are frequently used as tumor-targeting molecules. Over the years, several important membrane-associated proteases and receptors have been identified, validated, and subsequently used for preclinical radiotherapeutic development for prostate cancer. Prostate-specific membrane antigen (PSMA) is the most well-studied prostate cancer-associated protease in preclinical literature. PSMA-targeting radiotherapeutic agents are being investigated using high-affinity antibody- and small-molecule-based agents for safety and efficacy. Early generations of such agents were developed simply by replacing radionuclides of the imaging agents with therapeutic ones. Later, extensive structure-activity relationship studies were conducted to address the safety and efficacy issues obtained from initial patient data. Recent regulatory approval of the 177Lu-labeled low-molecular-weight agent, 177Lu-PSMA-617, is a significant accomplishment. Current preclinical experiments are focused on the structural modification of 177Lu-PSMA-617 and relevant investigational agents to increase tumor targeting and reduce off-target binding and toxicity in healthy organs. While lutetium-177 (177Lu) remains the most widely used radionuclide, radiolabeled analogs with iodine-131 (128I), yttrium-90 (89Y), copper-67 (67Cu), and terbium-161 (161Tb) have been evaluated as potential alternatives in recent years. In addition, agents carrying the α-particle-emitting radiohalogen, astatine-211 (211At), or radiometals, actinium-225 (225Ac), lead-212 (212Pb), radium-223 (223Ra), and thorium-227 (227Th), have been increasingly investigated in preclinical research. Besides PSMA-based radiotherapeutics, other prominent prostate cancer-related proteases, for example, human kallikrein peptidases (HK2 and HK3), have been explored using monoclonal-antibody-(mAb)-based targeting platforms. Several promising mAbs targeting receptors overexpressed on the different stages of prostate cancer have also been developed for radiopharmaceutical therapy, for example, Delta-like ligand 3 (DLL-3), CD46, and CUB domain-containing protein 1 (CDCP1). Progress is also being made using peptide-based targeting platforms for the gastrin-releasing peptide receptor (GRPR), a well-established membrane-associated receptor expressed in localized and metastatic prostate cancers. Furthermore, mechanism-driven combination therapies appear to be a burgeoning area in the context of preclinical prostate cancer radiotherapeutics. Here, we review the current developments related to the preclinical radiopharmaceutical therapy of prostate cancer. These are summarized in two major topics: (1) therapeutic radionuclides and (2) tumor-targeting approaches using monoclonal antibodies, small molecules, and peptides.
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Affiliation(s)
- Suresh Alati
- Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD; Sidney Kimmel Comprehensive Cancer Center, Baltimore, MD
| | - Rajan Singh
- Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD; Sidney Kimmel Comprehensive Cancer Center, Baltimore, MD
| | - Martin G Pomper
- Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD; Sidney Kimmel Comprehensive Cancer Center, Baltimore, MD
| | - Steven P Rowe
- Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD; Sidney Kimmel Comprehensive Cancer Center, Baltimore, MD
| | - Sangeeta Ray Banerjee
- Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD; Sidney Kimmel Comprehensive Cancer Center, Baltimore, MD.
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Boinapally S, Alati S, Jiang Z, Yan Y, Lisok A, Singh R, Lofland G, Minn I, Hobbs RF, Pomper MG, Banerjee SR. Preclinical Evaluation of a New Series of Albumin-Binding 177Lu-Labeled PSMA-Based Low-Molecular-Weight Radiotherapeutics. Molecules 2023; 28:6158. [PMID: 37630410 PMCID: PMC10459686 DOI: 10.3390/molecules28166158] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Revised: 08/12/2023] [Accepted: 08/17/2023] [Indexed: 08/27/2023] Open
Abstract
Prostate-specific membrane antigen (PSMA)-based low-molecular-weight agents using beta(β)-particle-emitting radiopharmaceuticals is a new treatment paradigm for patients with metastatic castration-resistant prostate cancer. Although results have been encouraging, there is a need to improve the tumor residence time of current PSMA-based radiotherapeutics. Albumin-binding moieties have been used strategically to enhance the tumor uptake and retention of existing PSMA-based investigational agents. Previously, we developed a series of PSMA-based, β-particle-emitting, low-molecular-weight compounds. From this series, 177Lu-L1 was selected as the lead agent because of its reduced off-target radiotoxicity in preclinical studies. The ligand L1 contains a PSMA-targeting Lys-Glu urea moiety with an N-bromobenzyl substituent in the ε-amino group of Lys. Here, we structurally modified 177Lu-L1 to improve tumor targeting using two known albumin-binding moieties, 4-(p-iodophenyl) butyric acid moiety (IPBA) and ibuprofen (IBU), and evaluated the effects of linker length and composition. Six structurally related PSMA-targeting ligands (Alb-L1-Alb-L6) were synthesized based on the structure of 177Lu-L1. The ligands were assessed for in vitro binding affinity and were radiolabeled with 177Lu following standard protocols. All 177Lu-labeled analogs were studied in cell uptake and selected cell efficacy studies. In vivo pharmacokinetics were investigated by conducting tissue biodistribution studies for 177Lu-Alb-L2-177Lu-Alb-L6 (2 h, 24 h, 72 h, and 192 h) in male NSG mice bearing human PSMA+ PC3 PIP and PSMA- PC3 flu xenografts. Preliminary therapeutic ratios of the agents were estimated from the area under the curve (AUC0-192h) of the tumors, blood, and kidney uptake values. Compounds were obtained in >98% radiochemical yields and >99% purity. PSMA inhibition constants (Kis) of the ligands were in the ≤10 nM range. The long-linker-based agents, 177Lu-Alb-L4 and 177Lu-Alb-L5, displayed significantly higher tumor uptake and retention (p < 0.001) than the short-linker-bearing 177Lu-Alb-L2 and 177Lu-Alb-L3 and a long polyethylene glycol (PEG) linker-bearing agent, 177Lu-Alb-L6. The area under the curve (AUC0-192h) of the PSMA+ PC3 PIP tumor uptake of 177Lu-Alb-L4 and 177Lu-Alb-L5 were >4-fold higher than 177Lu-Alb-L2, 177Lu-Alb-L3, and 177Lu-Alb-L6, respectively. Also, the PSMA+ PIP tumor uptake (AUC0-192h) of 177Lu-Alb-L2 and 177Lu-Alb-L3 was ~1.5-fold higher than 177Lu-Alb-L6. However, the lowest blood AUC0-192h and kidney AUC0-192h were associated with 177Lu-Alb-L6 from the series. Consequently, 177Lu-Alb-L6 displayed the highest ratios of AUC(tumor)-to-AUC(blood) and AUC(tumor)-to-AUC(kidney) values from the series. Among the other agents, 177Lu-Alb-L4 demonstrated a nearly similar ratio of AUC(tumor)-to-AUC(blood) as 177Lu-Alb-L6. The tumor-to-blood ratio was the dose-limiting therapeutic ratio for all of the compounds. Conclusions: 177Lu-Alb-L4 and 177Lu-Alb-L6 showed high tumor uptake in PSMA+ tumors and tumor-to-blood ratios. The data suggest that linker length and composition can be modulated to generate an optimized therapeutic agent.
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Affiliation(s)
- Srikanth Boinapally
- Russell H. Morgan Department of Radiology and Radiological Science, 1550 Orleans Street, Cancer Research Building 2, Baltimore, MD 21287, USA; (S.B.); (S.A.); (Z.J.); (I.M.); (R.F.H.); (M.G.P.)
| | - Suresh Alati
- Russell H. Morgan Department of Radiology and Radiological Science, 1550 Orleans Street, Cancer Research Building 2, Baltimore, MD 21287, USA; (S.B.); (S.A.); (Z.J.); (I.M.); (R.F.H.); (M.G.P.)
| | - Zirui Jiang
- Russell H. Morgan Department of Radiology and Radiological Science, 1550 Orleans Street, Cancer Research Building 2, Baltimore, MD 21287, USA; (S.B.); (S.A.); (Z.J.); (I.M.); (R.F.H.); (M.G.P.)
| | - Yu Yan
- Russell H. Morgan Department of Radiology and Radiological Science, 1550 Orleans Street, Cancer Research Building 2, Baltimore, MD 21287, USA; (S.B.); (S.A.); (Z.J.); (I.M.); (R.F.H.); (M.G.P.)
| | - Alla Lisok
- Russell H. Morgan Department of Radiology and Radiological Science, 1550 Orleans Street, Cancer Research Building 2, Baltimore, MD 21287, USA; (S.B.); (S.A.); (Z.J.); (I.M.); (R.F.H.); (M.G.P.)
| | - Rajan Singh
- Russell H. Morgan Department of Radiology and Radiological Science, 1550 Orleans Street, Cancer Research Building 2, Baltimore, MD 21287, USA; (S.B.); (S.A.); (Z.J.); (I.M.); (R.F.H.); (M.G.P.)
| | - Gabriela Lofland
- Russell H. Morgan Department of Radiology and Radiological Science, 1550 Orleans Street, Cancer Research Building 2, Baltimore, MD 21287, USA; (S.B.); (S.A.); (Z.J.); (I.M.); (R.F.H.); (M.G.P.)
| | - Il Minn
- Russell H. Morgan Department of Radiology and Radiological Science, 1550 Orleans Street, Cancer Research Building 2, Baltimore, MD 21287, USA; (S.B.); (S.A.); (Z.J.); (I.M.); (R.F.H.); (M.G.P.)
| | - Robert F. Hobbs
- Russell H. Morgan Department of Radiology and Radiological Science, 1550 Orleans Street, Cancer Research Building 2, Baltimore, MD 21287, USA; (S.B.); (S.A.); (Z.J.); (I.M.); (R.F.H.); (M.G.P.)
| | - Martin G. Pomper
- Russell H. Morgan Department of Radiology and Radiological Science, 1550 Orleans Street, Cancer Research Building 2, Baltimore, MD 21287, USA; (S.B.); (S.A.); (Z.J.); (I.M.); (R.F.H.); (M.G.P.)
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, MD 21287, USA
| | - Sangeeta Ray Banerjee
- Russell H. Morgan Department of Radiology and Radiological Science, 1550 Orleans Street, Cancer Research Building 2, Baltimore, MD 21287, USA; (S.B.); (S.A.); (Z.J.); (I.M.); (R.F.H.); (M.G.P.)
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, MD 21287, USA
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Jang A, Kendi AT, Johnson GB, Halfdanarson TR, Sartor O. Targeted Alpha-Particle Therapy: A Review of Current Trials. Int J Mol Sci 2023; 24:11626. [PMID: 37511386 PMCID: PMC10380274 DOI: 10.3390/ijms241411626] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 07/08/2023] [Accepted: 07/17/2023] [Indexed: 07/30/2023] Open
Abstract
Radiopharmaceuticals are rapidly developing as a field, with the successful use of targeted beta emitters in neuroendocrine tumors and prostate cancer serving as catalysts. Targeted alpha emitters are in current development for several potential oncologic indications. Herein, we review the three most prevalently studied conjugated/chelated alpha emitters (225actinium, 212lead, and 211astatine) and focus on contemporary clinical trials in an effort to more fully appreciate the breadth of the current evaluation. Phase I trials targeting multiple diseases are now underway, and at least one phase III trial (in selected neuroendocrine cancers) is currently in the initial stages of recruitment. Combination trials are now also emerging as alpha emitters are integrated with other therapies in an effort to create solutions for those with advanced cancers. Despite the promise of targeted alpha therapies, many challenges remain. These challenges include the development of reliable supply chains, the need for a better understanding of the relationships between administered dose and absorbed dose in both tissue and tumor and how that predicts outcomes, and the incomplete understanding of potential long-term deleterious effects of the alpha emitters. Progress on multiple fronts is necessary to bring the potential of targeted alpha therapies into the clinic.
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Affiliation(s)
- Albert Jang
- Deming Department of Medicine, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Ayse T Kendi
- Department of Radiology, Mayo Clinic, Rochester, MN 55905, USA
| | - Geoffrey B Johnson
- Department of Radiology, Mayo Clinic, Rochester, MN 55905, USA
- Department of Immunology, Mayo Clinic, Rochester, MN 55905, USA
| | | | - Oliver Sartor
- Department of Radiology, Mayo Clinic, Rochester, MN 55905, USA
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA
- Department of Urology, Mayo Clinic, Rochester, MN 55905, USA
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9
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Lu Q, Long Y, Gai Y, Liu Q, Jiang D, Lan X. [ 177Lu]Lu-PSMA-617 theranostic probe for hepatocellular carcinoma imaging and therapy. Eur J Nucl Med Mol Imaging 2023; 50:2342-2352. [PMID: 36877233 DOI: 10.1007/s00259-023-06155-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Accepted: 02/13/2023] [Indexed: 03/07/2023]
Abstract
PURPOSE This study aimed to explore the feasibility of using [177Lu]Lu-prostate-specific membrane antigen (PSMA)-617 and [177Lu]Lu-Evans blue (EB)-PSMA-617 for in vivo radioligand therapy by single-dose administration in a PSMA-positive hepatocellular carcinoma (HCC) xenograft mouse model. METHODS [177Lu]Lu-PSMA-617 and [177Lu]Lu-EB-PSMA-617 were prepared, and labelling efficiency and radiochemical purity were determined. A HepG2 human HCC subcutaneous xenograft mouse model was established. After intravenous injection of [177Lu]Lu-PSMA-617 or [177Lu]Lu-EB-PSMA-617 (37 MBq) into the mouse model, single-photon emission computed tomography/computed tomography (SPECT/CT) was performed. Biodistribution studies were conducted to verify targeting specificity and pharmacokinetics. In the radioligand therapy study, mice were randomized into 4 groups: 37 MBq [177Lu]Lu-PSMA-617, 18.5 MBq [177Lu]Lu-PSMA-617, 7.4 MBq [177Lu]Lu-EB-PSMA-617, and saline (control). A single-dose administration was applied at the beginning of therapy studies. Tumor volume, body weight, and survival were monitored every 2 days. After the end of therapy, mice were euthanized. Tumors were then weighed, and systemic toxicity was evaluated via blood testing and histological examination of healthy organs. RESULTS [177Lu]Lu-PSMA-617 and [177Lu]Lu-EB-PSMA-617 were successfully prepared with high purity and stability. SPECT/CT and biodistribution showed that tumor uptake was higher and persisted longer for [177Lu]Lu-EB-PSMA-617 compared with [177Lu]Lu-PSMA-617. [177Lu]Lu-PSMA-617 was rapidly cleared from the blood, while [177Lu]Lu-EB-PSMA-617 persisted for significantly longer. In radioligand therapy studies, tumor growth was significantly suppressed in the 37 MBq [177Lu]Lu-PSMA-617, 18.5 MBq [177Lu]Lu-PSMA-617, and 7.4 MBq [177Lu]Lu-EB-PSMA-617 groups compared to the saline group. Median survival was 40, 44, 43, and 30 days, respectively. No healthy organ toxicity was observed in safety and tolerability evaluation. CONCLUSIONS Radioligand therapy using [177Lu]Lu-PSMA-617 and [177Lu]Lu-EB-PSMA-617 significantly suppressed tumor growth and prolonged survival time in PSMA-positive HCC xenograft mice without obvious toxicity. These radioligands appear promising for clinical use in humans, and future studies are warranted.
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Affiliation(s)
- Qiaomiao Lu
- Department of Nuclear Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430022, China
- Hubei Key Laboratory of Molecular Imaging, Wuhan, Hubei, 430022, China
| | - Yu Long
- Department of Nuclear Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430022, China
- Hubei Key Laboratory of Molecular Imaging, Wuhan, Hubei, 430022, China
| | - Yongkang Gai
- Department of Nuclear Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430022, China
- Hubei Key Laboratory of Molecular Imaging, Wuhan, Hubei, 430022, China
- Key Laboratory of Biological Targeted Therapy of the Ministry of Education, Wuhan, 430022, China
| | - Qingyao Liu
- Department of Nuclear Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430022, China
- Hubei Key Laboratory of Molecular Imaging, Wuhan, Hubei, 430022, China
- Key Laboratory of Biological Targeted Therapy of the Ministry of Education, Wuhan, 430022, China
| | - Dawei Jiang
- Department of Nuclear Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430022, China
- Hubei Key Laboratory of Molecular Imaging, Wuhan, Hubei, 430022, China
- Key Laboratory of Biological Targeted Therapy of the Ministry of Education, Wuhan, 430022, China
| | - Xiaoli Lan
- Department of Nuclear Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430022, China.
- Hubei Key Laboratory of Molecular Imaging, Wuhan, Hubei, 430022, China.
- Key Laboratory of Biological Targeted Therapy of the Ministry of Education, Wuhan, 430022, China.
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10
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Krasnovskaya OO, Abramchuck D, Erofeev A, Gorelkin P, Kuznetsov A, Shemukhin A, Beloglazkina EK. Recent Advances in 64Cu/ 67Cu-Based Radiopharmaceuticals. Int J Mol Sci 2023; 24:ijms24119154. [PMID: 37298101 DOI: 10.3390/ijms24119154] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Revised: 05/19/2023] [Accepted: 05/21/2023] [Indexed: 06/12/2023] Open
Abstract
Copper-64 (T1/2 = 12.7 h) is a positron and beta-emitting isotope, with decay characteristics suitable for both positron emission tomography (PET) imaging and radiotherapy of cancer. Copper-67 (T1/2 = 61.8 h) is a beta and gamma emitter, appropriate for radiotherapy β-energy and with a half-life suitable for single-photon emission computed tomography (SPECT) imaging. The chemical identities of 64Cu and 67Cu isotopes allow for convenient use of the same chelating molecules for sequential PET imaging and radiotherapy. A recent breakthrough in 67Cu production opened previously unavailable opportunities for a reliable source of 67Cu with high specific activity and purity. These new opportunities have reignited interest in the use of copper-containing radiopharmaceuticals for the therapy, diagnosis, and theranostics of various diseases. Herein, we summarize recent (2018-2023) advances in the use of copper-based radiopharmaceuticals for PET, SPECT imaging, radiotherapy, and radioimmunotherapy.
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Affiliation(s)
- Olga O Krasnovskaya
- Chemistry Department, Lomonosov Moscow State University, Leninskie Gory, 1/3, 119991 Moscow, Russia
| | - Daniil Abramchuck
- Chemistry Department, Lomonosov Moscow State University, Leninskie Gory, 1/3, 119991 Moscow, Russia
| | - Alexander Erofeev
- Chemistry Department, Lomonosov Moscow State University, Leninskie Gory, 1/3, 119991 Moscow, Russia
- Research Laboratory of Biophysics, National University of Science and Technology (MISIS), Leninskiy Prospect 4, 119049 Moscow, Russia
| | - Peter Gorelkin
- Research Laboratory of Biophysics, National University of Science and Technology (MISIS), Leninskiy Prospect 4, 119049 Moscow, Russia
| | - Alexander Kuznetsov
- Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Leninskie Gory, 1, Bld. 2, 119991 Moscow, Russia
- Department of Physics, Lomonosov Moscow State University, Leninskie Gory, 1/2, 119991 Moscow, Russia
| | - Andrey Shemukhin
- Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Leninskie Gory, 1, Bld. 2, 119991 Moscow, Russia
| | - Elena K Beloglazkina
- Chemistry Department, Lomonosov Moscow State University, Leninskie Gory, 1/3, 119991 Moscow, Russia
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11
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DiMagno SG, Babich JW. Advanced Fibroblast Activation Protein-Ligand Developments: FAP Imaging Agents: A Review of the Structural Requirements. PET Clin 2023:S1556-8598(23)00028-7. [PMID: 37117123 DOI: 10.1016/j.cpet.2023.03.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
Fibroblast activation protein-α (FAP) has attracted increasing attention as a selective marker of cancer-associated fibroblasts (CAFs) and more broadly, of activated fibroblasts in tissues undergoing remodeling of their ECM due to chronic inflammation, fibrosis, or wound healing. Since FAP is critical to the initiation of metastatic growth, its expression will serve as a molecular marker to detect tumors at an earlier stage of development compared to currently available methods. The design of high affinity small molecule FAP inhibitor will allow for noninvasive imaging of activated fibroblast in cancer patients. Small molecule inhibitors of FAP are being developed for targeted radiotherapy of tumors.
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Affiliation(s)
- Stephen G DiMagno
- Ratio Therapeutics, Inc., One Design Center Place, Suite# 19-601, Boston, MA 02210, USA
| | - John W Babich
- Ratio Therapeutics, Inc., One Design Center Place, Suite# 19-601, Boston, MA 02210, USA.
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12
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Zhang H, Rao M, Zhao H, Ren J, Hao L, Zhong M, Chen Y, Yang X, Feng Y, Yuan G. Imageological/Structural Study regarding the Improved Pharmacokinetics by 68Ga-Labeled PEGylated PSMA Multimer in Prostate Cancer. Pharmaceuticals (Basel) 2023; 16:ph16040589. [PMID: 37111347 PMCID: PMC10144514 DOI: 10.3390/ph16040589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 04/07/2023] [Accepted: 04/10/2023] [Indexed: 04/29/2023] Open
Abstract
PMSA (prostate-specific membrane antigen) is currently the most significant target for diagnosing and treating PCa (prostate cancer). Herein, we reported a series 68Ga/177Lu-labeled multimer PSMA tracer conjugating with PEG chain, including [68Ga]Ga-DOTA-(1P-PEG4), [68Ga]Ga-DOTA-(2P-PEG0), [68Ga]Ga-DOTA-(2P-PEG4), and [68Ga]Ga/[177Lu]Lu-DOTA-(2P-PEG4)2, which showed an advantage of a multivalent effect and PEGylation to achieve higher tumor accumulation and faster kidney clearance. To figure out how structural optimizations based on a PSMA multimer and PEGylation influence the probe's tumor-targeting ability, biodistribution, and metabolism, we examined PSMA molecular probes' affinities to PC-3 PIP (PSMA-highly-expressed PC-3 cell line), and conducted pharmacokinetics analysis, biodistribution detection, small animal PET/CT, and SPECT/CT imaging. The results showed that PEG4 and PSMA dimer optimizations enhanced the probes' tumor-targeting ability in PC-3 PIP tumor-bearing mice models. Compared with the PSMA monomer, the PEGylated PSMA dimer reduced the elimination half-life in the blood and increased uptake in the tumor, and the biodistribution results were consistent with PET/CT imaging results. [68Ga]Ga-DOTA-(2P-PEG4)2 exhibited higher tumor-to-organ ratios. When labeled by lutetium-177, relatively high accumulation of DOTA-(2P-PEG4)2 was still detected in PC-3 PIP tumor-bearing mice models after 48 h, indicating its prolonged tumor retention time. Given the superiority in imaging, simple synthetic processes, and structural stability, DOTA-(2P-PEG4)2 is expected to be a promising tumor-targeting diagnostic molecular probe in future clinical practice.
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Affiliation(s)
- Huihui Zhang
- Department of Nuclear Medicine, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
| | - Maohua Rao
- Department of Nuclear Medicine, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
| | - Huayi Zhao
- Department of Nuclear Medicine, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
| | - Jianli Ren
- Chongqing Key Laboratory of Ultrasound Molecular Imaging, Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
| | - Lan Hao
- Chongqing Key Laboratory of Ultrasound Molecular Imaging, Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
| | - Meng Zhong
- Department of Pharmacy, The Affiliated Hospital of Southwest Medical University, Luzhou 646600, China
| | - Yue Chen
- Nuclear Medicine and Molecular Imaging Key Laboratory of Sichuan Province, Luzhou 646600, China
| | - Xia Yang
- Institute of Nuclear Physics and Chemistry, Academy of Engineering Physics, Mianyang 621900, China
| | - Yue Feng
- Nuclear Medicine and Molecular Imaging Key Laboratory of Sichuan Province, Luzhou 646600, China
| | - Gengbiao Yuan
- Department of Nuclear Medicine, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
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13
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Sun J, Huangfu Z, Yang J, Wang G, Hu K, Gao M, Zhong Z. Imaging-guided targeted radionuclide tumor therapy: From concept to clinical translation. Adv Drug Deliv Rev 2022; 190:114538. [PMID: 36162696 DOI: 10.1016/j.addr.2022.114538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Revised: 09/03/2022] [Accepted: 09/11/2022] [Indexed: 01/24/2023]
Abstract
Since the first introduction of sodium iodide I-131 for use with thyroid patients almost 80 years ago, more than 50 radiopharmaceuticals have reached the markets for a wide range of diseases, especially cancers. The nuclear medicine paradigm also shifts from solely molecular imaging or radionuclide therapy to imaging-guided radionuclide therapy, which is deemed a vital component of precision cancer therapy and an emerging medical modality for personalized medicine. The imaging-guided radionuclide therapy highlights the systematic integration of targeted nuclear diagnostics and radionuclide therapeutics. Regarding this, nuclear imaging serves to "visualize" the lesions and guide the therapeutic strategy, followed by administration of a precise patient specific dose of radiotherapeutics for treatment according to the absorbed dose to different organs and tumors calculated by dosimetry tools, and finally repeated imaging to predict the prognosis. This strategy leads to significantly enhanced therapeutic efficacy, improved patient outcomes, and manageable adverse events. In this review, we provide an overview of imaging-guided targeted radionuclide therapy for different tumors such as advanced prostate cancer and neuroendocrine tumors, with a focus on development of new radioligands and their preclinical and clinical results, and further discuss about challenges and future perspectives.
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Affiliation(s)
- Juan Sun
- College of Pharmaceutical Sciences, and State Key Laboratory of Radiation Medicine and Protection, Soochow University, Suzhou 215123, People's Republic of China; Biomedical Polymers Laboratory, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, People's Republic of China
| | - Zhenyuan Huangfu
- College of Pharmaceutical Sciences, and State Key Laboratory of Radiation Medicine and Protection, Soochow University, Suzhou 215123, People's Republic of China; Biomedical Polymers Laboratory, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, People's Republic of China
| | - Jiangtao Yang
- College of Pharmaceutical Sciences, and State Key Laboratory of Radiation Medicine and Protection, Soochow University, Suzhou 215123, People's Republic of China; Biomedical Polymers Laboratory, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, People's Republic of China
| | - Guanglin Wang
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection & School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou 215123, People's Republic of China.
| | - Kuan Hu
- Department of Advanced Nuclear Medicine Sciences, Institute for Quantum Medical Sciences, Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan.
| | - Mingyuan Gao
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection & School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou 215123, People's Republic of China
| | - Zhiyuan Zhong
- College of Pharmaceutical Sciences, and State Key Laboratory of Radiation Medicine and Protection, Soochow University, Suzhou 215123, People's Republic of China; Biomedical Polymers Laboratory, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, People's Republic of China.
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14
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Xu M, Zhang P, Ding J, Chen J, Huo L, Liu Z. Albumin Binder-Conjugated Fibroblast Activation Protein Inhibitor Radiopharmaceuticals for Cancer Therapy. J Nucl Med 2022; 63:952-958. [PMID: 34593598 PMCID: PMC9157728 DOI: 10.2967/jnumed.121.262533] [Citation(s) in RCA: 46] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 09/25/2021] [Indexed: 11/16/2022] Open
Abstract
Fibroblast activation protein (FAP) has become an attractive target for diagnosis and therapy, and a series of FAP inhibitor (FAPI)-based radiotracers has been developed and had excellent performance for diagnosis outcomes in clinical applications. Yet, their fast clearance and insufficient tumor retention have hampered their further clinical application in cancer treatment. In this study, we developed 2 albumin binder-conjugated FAPI radiotracers, TEFAPI-06 and TEFAPI-07. They were derived from FAPI-04 and were optimized by conjugating 2 types of well-studied albumin binders, 4-(p-iodophenyl) butyric acid moiety (TEFAPI-06) and truncated Evans blue moiety (TEFAPI-07), to try to overcome the above limitations at the expense of prolonging the blood circulation. Methods: TEFAPI-06 and TEFAPI-07 were synthesized and labeled with 68Ga, 86Y, and 177Lu successfully. A series of cell assays was performed to identify the binding affinity and FAP specificity in vitro. PET imaging, SPECT imaging, and biodistribution studies were performed to evaluate the pharmacokinetics in pancreatic cancer patient-derived xenograft (PDX) animal models. The cancer treatment efficacy of 177Lu-TEFAPI-06 and 177Lu-TEFAPI-07 were evaluated in pancreatic cancer PDX-bearing mice. Results: The binding affinities (dissociation constants) to FAP of 68Ga-TEFAPI-06 and 68Ga-TEFAPI-07 were 10.16 ± 2.56 nM and 7.81 ± 2.28 nM, respectively, which were comparable with that of 68Ga-FAPI-04. Comparative PET imaging of HT-1080-FAP and HT-1080 tumor-bearing mice and a blocking study showed the FAP-targeting ability in vivo of these 2 tracers. Compared with 177Lu-FAPI-04, PET imaging, SPECT imaging, and biodistribution studies of TEFAPI-06 and TEFAPI-07 demonstrated their remarkably enhanced tumor accumulation and retention, respectively. Notable tumor growth inhibition by 177Lu-TEFAPI-06 and 177Lu-TEFAPI-07 were observed, whereas the control group and the group treated by 177Lu-FAPI-04 showed a slight therapeutic effect. Conclusion: Two albumin binder-conjugated FAPI radiopharmaceuticals have been developed and evaluated in vitro and in vivo. Significantly improved tumor uptake and retention were observed, compared with the original FAPI tracer. Both 177Lu-TEFAPI-06 and 177Lu-TEFAPI-07 showed remarkable growth inhibition of PDX tumors, whereas the side effects were almost negligible, demonstrating that these radiopharmaceuticals are promising for further clinical translational studies.
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Affiliation(s)
- Mengxin Xu
- Radiochemistry and Radiation Chemistry Key Laboratory of Fundamental Science, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Pu Zhang
- Radiochemistry and Radiation Chemistry Key Laboratory of Fundamental Science, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Jie Ding
- Department of Nuclear Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China; and
| | - Junyi Chen
- Radiochemistry and Radiation Chemistry Key Laboratory of Fundamental Science, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Li Huo
- Department of Nuclear Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China; and
| | - Zhibo Liu
- Radiochemistry and Radiation Chemistry Key Laboratory of Fundamental Science, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, China;
- Peking University-Tsinghua University Center for Life Sciences, Beijing, China
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15
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Tschan VJ, Borgna F, Busslinger SD, Stirn M, Rodriguez JMM, Bernhardt P, Schibli R, Müller C. Preclinical investigations using [177Lu]Lu-Ibu-DAB-PSMA toward its clinical translation for radioligand therapy of prostate cancer. Eur J Nucl Med Mol Imaging 2022; 49:3639-3650. [PMID: 35635566 PMCID: PMC9399046 DOI: 10.1007/s00259-022-05837-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Accepted: 05/08/2022] [Indexed: 12/21/2022]
Abstract
Abstract[177Lu]Lu-Ibu-DAB-PSMA was previously characterized with moderate albumin-binding properties enabling high tumor accumulation but reasonably low retention in the blood. The aim of this study was to investigate [177Lu]Lu-Ibu-DAB-PSMA in preclinical in vivo experiments and compare its therapeutic efficacy and potential undesired side effects with those of [177Lu]Lu-PSMA-617 and the previously developed [177Lu]Lu-PSMA-ALB-56. BALB/c nude mice without tumors were investigated on Day 10 and 28 after injection of 10 MBq radioligand. It was revealed that most plasma parameters were in the same range for all groups of mice and histopathological examinations of healthy tissue did not show any alternations in treated mice as compared to untreated controls. Based on these results, a therapy study over twelve weeks was conducted with PC-3 PIP tumor-bearing mice for comparison of the radioligands’s therapeutic efficacy up to an activity of 10 MBq (1 nmol) per mouse. In agreement with the increased mean absorbed tumor dose, [177Lu]Lu-Ibu-DAB-PSMA (~ 6.6 Gy/MBq) was more effective to inhibit tumor growth than [177Lu]Lu-PSMA-617 (~ 4.5 Gy/MBq) and only moderately less potent than [177Lu]Lu-PSMA-ALB-56 (~ 8.1 Gy/MBq). As a result, the survival of mice treated with 2 MBq of an albumin-binding radioligand was significantly increased (p < 0.05) compared to that of mice injected with [177Lu]Lu-PSMA-617 or untreated controls. The majority of mice treated with 5 MBq or 10 MBq [177Lu]Lu-Ibu-DAB-PSMA or [177Lu]Lu-PSMA-ALB-56 were still alive at study end. Hemograms of immunocompetent mice injected with 30 MBq [177Lu]Lu-Ibu-DAB-PSMA or 30 MBq [177Lu]Lu-PSMA-617 showed values in the same range as untreated controls. This was, however, not the case for mice treated with [177Lu]Lu-PSMA-ALB-56 which revealed a drop in lymphocytes and hemoglobin at Day 10 and Day 28 after injection. The data of this study demonstrated a significant therapeutic advantage of [177Lu]Lu-Ibu-DAB-PSMA over [177Lu]Lu-PSMA-617 and a more favorable safety profile as compared to that of [177Lu]Lu-PSMA-ALB-56. Based on these results, [177Lu]Lu-Ibu-DAB-PSMA may has the potential for a clinical translation.
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Affiliation(s)
- Viviane J Tschan
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, 5232, Villigen-PSI, Switzerland
| | - Francesca Borgna
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, 5232, Villigen-PSI, Switzerland
| | - Sarah D Busslinger
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, 5232, Villigen-PSI, Switzerland
| | - Martina Stirn
- Clinical Laboratory, Department of Clinical Diagnostics and Services, Vetsuisse Faculty, University of Zurich, 8057, Zurich, Switzerland
| | - Josep M Monné Rodriguez
- Laboratory for Animal Model Pathology (LAMP), Institute of Veterinary Pathology, Vetsuisse Faculty, University of Zurich, 8057, Zurich, Switzerland
| | - Peter Bernhardt
- Department of Radiation Physics, Institution of Clinical Science, Sahlgrenska Academy, University of Gothenburg, 41345, Gothenburg, Sweden
| | - Roger Schibli
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, 5232, Villigen-PSI, Switzerland
- Department of Chemistry and Applied Biosciences, ETH Zurich, 8093, Zurich, Switzerland
| | - Cristina Müller
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, 5232, Villigen-PSI, Switzerland.
- Department of Chemistry and Applied Biosciences, ETH Zurich, 8093, Zurich, Switzerland.
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16
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Jeitner TM, Babich JW, Kelly JM. Advances in PSMA theranostics. Transl Oncol 2022; 22:101450. [PMID: 35597190 PMCID: PMC9123266 DOI: 10.1016/j.tranon.2022.101450] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 05/04/2022] [Accepted: 05/08/2022] [Indexed: 12/15/2022] Open
Abstract
PSMA is an appealing target for theranostic because it is a transmembrane protein with a known substrate that is overexpessed on prostate cancer cells and internalizes upon ligand binding. There are a number of PSMA theranostic ligands in clinical evaluation, clinical trial, or clinically approved. PSMA theranostic ligands increase progression-free survival, overall survival, and pain in patients with metastatic castration resistant prostate cancer. A major obstacle to PSMA-targeted radioligand therapy is off-target toxicity in salivary glands.
The validation of prostate specific membrane antigen (PSMA) as a molecular target in metastatic castration-resistant prostate cancer has stimulated the development of multiple classes of theranostic ligands that specifically target PSMA. Theranostic ligands are used to image disease or selectively deliver cytotoxic radioactivity to cells expressing PSMA according to the radioisotope conjugated to the ligand. PSMA theranostics is a rapidly advancing field that is now integrating into clinical management of prostate cancer patients. In this review we summarize published research describing the biological role(s) and activity of PSMA, highlight the most clinically advanced PSMA targeting molecules and biomacromolecules, and identify next generation PSMA ligands that aim to further improve treatment efficacy. The goal of this review is to provide a comprehensive assessment of the current state-of-play and a roadmap to achieving further advances in PSMA theranostics.
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Affiliation(s)
- Thomas M Jeitner
- Molecular Imaging Innovations Institute, Department of Radiology, Weill Cornell Medicine, Belfer Research Building, 413 East 69th Street, Room BB-1604, New York, NY 10021, USA
| | - John W Babich
- Molecular Imaging Innovations Institute, Department of Radiology, Weill Cornell Medicine, Belfer Research Building, 413 East 69th Street, Room BB-1604, New York, NY 10021, USA; Weill Cornell Medicine, Sandra and Edward Meyer Cancer Center, New York, NY 10021, USA; Weill Cornell Medicine, Citigroup Biomedical Imaging Center, New York, NY 10021, USA
| | - James M Kelly
- Molecular Imaging Innovations Institute, Department of Radiology, Weill Cornell Medicine, Belfer Research Building, 413 East 69th Street, Room BB-1604, New York, NY 10021, USA; Weill Cornell Medicine, Citigroup Biomedical Imaging Center, New York, NY 10021, USA.
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17
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Borgna F, Deberle LM, Busslinger SD, Tschan VJ, Walde LM, Becker AE, Schibli R, Müller C. Preclinical Investigations to Explore the Difference between the Diastereomers [ 177Lu]Lu-SibuDAB and [ 177Lu]Lu-RibuDAB toward Prostate Cancer Therapy. Mol Pharm 2022; 19:2105-2114. [PMID: 35544699 DOI: 10.1021/acs.molpharmaceut.1c00994] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
[177Lu]Lu-Ibu-DAB-PSMA, a radioligand modified with ibuprofen as the albumin binder, showed higher accumulation in PSMA-positive tumors of mice than the clinically used [177Lu]Lu-PSMA-617 but lower retention in non-targeted tissues than previously developed albumin-binding PSMA radioligands. The aim of this study was to investigate whether the stereochemistry of the incorporated ibuprofen affects the radioligand's in vitro and in vivo properties and to select the more favorable radioligand for further development. For this purpose, SibuDAB and RibuDAB containing (S)- and (R)-ibuprofen, respectively, were synthesized and labeled with lutetium-177. In vitro, the two isomers had similar properties; however, [177Lu]Lu-SibuDAB showed increased binding to mouse and human plasma proteins (91 ± 1 and 88 ± 2%, respectively) compared to [177Lu]Lu-RibuDAB (75 ± 2 and 79 ± 2%, respectively). In vivo, [177Lu]Lu-SibuDAB was metabolically more stable than [177Lu]Lu-RibuDAB with ∼90 vs ∼67% intact radioligand detected in the blood at 4 h post injection (p.i.). In line with the lower albumin-binding affinity, the blood clearance of [177Lu]Lu-RibuDAB in mice was considerably faster [27% of injected activity (% IA), 1 h p.i.] than for [177Lu]Lu-SibuDAB (50% IA, 1 h p.i.). Time-dependent biodistribution studies performed in tumor-bearing athymic nude mice showed high PSMA-specific tumor uptake for both isomers. A twofold increased area under the curve (AUC0→8d) of the blood retention was determined for [177Lu]Lu-SibuDAB as compared to [177Lu]Lu-RibuDAB, whereas the kidney AUC0→8d value of [177Lu]Lu-SibuDAB was only half as high as for [177Lu]Lu-RibuDAB. As a result, a more favorable tumor-to-kidney AUC0→8d ratio was obtained for [177Lu]Lu-SibuDAB, which was also visualized on SPECT/CT images. Based on its improved kidney clearance and higher metabolic stability, [177Lu]Lu-SibuDAB was selected as the more favorable radioligand. Therapy studies performed with [177Lu]Lu-SibuDAB (5 MBq/mouse) demonstrated the anticipated therapeutic superiority over the current gold-standard [177Lu]Lu-PSMA-617 (5 MBq/mouse). The significantly increased survival time of mice treated with [177Lu]Lu-SibuDAB as compared to those injected with [177Lu]Lu-PSMA-617 justifies further development of this novel radioligand toward clinical application.
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Affiliation(s)
- Francesca Borgna
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, Villigen-PSI 5232, Switzerland
| | - Luisa M Deberle
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, Villigen-PSI 5232, Switzerland
| | - Sarah D Busslinger
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, Villigen-PSI 5232, Switzerland
| | - Viviane J Tschan
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, Villigen-PSI 5232, Switzerland
| | - Laura M Walde
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, Villigen-PSI 5232, Switzerland
| | - Anna E Becker
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, Villigen-PSI 5232, Switzerland
| | - Roger Schibli
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, Villigen-PSI 5232, Switzerland.,Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich 8093, Switzerland
| | - Cristina Müller
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, Villigen-PSI 5232, Switzerland.,Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich 8093, Switzerland
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18
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Development and Evaluation of a PSMA-Targeted Nanosystem Co-Packaging Docetaxel and Androgen Receptor siRNA for Castration-Resistant Prostate Cancer Treatment. Pharmaceutics 2022; 14:pharmaceutics14050964. [PMID: 35631549 PMCID: PMC9146571 DOI: 10.3390/pharmaceutics14050964] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 04/01/2022] [Accepted: 04/26/2022] [Indexed: 11/17/2022] Open
Abstract
Primary prostate cancer (PC) progresses to castration-resistant PC (CRPC) during androgen deprivation therapy (ADR) in early stages of prostate cancer. Thus, rather than blocking the androgen-related pathway further, docetaxel (DTX)-based therapy has become the most effective and standard first-line chemotherapy for CRPC. Although the therapy is successful in prolonging the survival of patients with CRPC, chemotherapy resistance develops due to the abnormal activation of the androgen receptor (AR) signaling pathway. Thus, to optimize DTX efficacy, continued maximum suppression of androgen levels and AR signaling is required. Here, we designed a prostate-specific membrane antigen (PSMA)-targeted nanosystem to carry both DTX and AR siRNA (Di-PP/AR-siRNA/DTX) for CRPC treatment. Specifically, DTX was encapsulated into the hydrophobic inner layer, and the AR siRNA was then condensed with the cationic PEI block in the hydrophilic outer layer of the PEI-PLGA polymeric micelles. The micelles were further coated with PSMA-targeted anionic polyethylene glycol-polyaspartic acid (Di-PEG-PLD). In vitro and in vivo results demonstrated that the resulting Di-PP/AR-siRNA/DTX exhibited prolonged blood circulation, selective targeting, and enhanced antitumor effects. Consequently, Di-PP/AR-siRNA/DTX holds great potential for efficient CRPC treatment by combining chemotherapy and siRNA silencing of androgen-related signaling pathways.
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Ren Y, Liu T, Liu C, Guo X, Wang F, Zhu H, Yang Z. An Albumin-Binding PSMA Ligand with Higher Tumor Accumulation for PET Imaging of Prostate Cancer. Pharmaceuticals (Basel) 2022; 15:ph15050513. [PMID: 35631340 PMCID: PMC9143078 DOI: 10.3390/ph15050513] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 04/07/2022] [Accepted: 04/19/2022] [Indexed: 02/01/2023] Open
Abstract
Prostate-specific membrane antigen (PSMA) is an ideal target for the diagnosis and treatment of prostate cancer. Due to the short half-life in blood, small molecules/peptides are rapidly cleared by the circulatory system. Prolonging the half-life of PSMA probes has been considered as an effective strategy to improve the tumor detection. Herein, we reported a 64Cu-labeled PSMA tracer conjugating with maleimidopropionic acid (MPA), 64Cu-PSMA-CM, which showed an excellent ability to detect PSMA-overexpressing tumors in delayed time. Cell experiments in PSMA-positive 22Rv1 cells, human serum albumin binding affinity, and micro-PET imaging studies in 22Rv1 model were performed to investigate the albumin binding capacity and PSMA specificity. Comparisons with 64Cu-PSMA-BCH were performed to explore the influence of MPA on the biological properties. 64Cu-PSMA-CM could be quickly prepared within 30 min. The uptake of 64Cu-PSMA-CM in 22Rv1 cells increased over time and it could bind to HSA with a high protein binding ratio (67.8 ± 1.5%). When compared to 64Cu-PSMA-BCH, 64Cu-PSMA-CM demonstrated higher and prolonged accumulation in 22Rv1 tumors, contributing to high tumor-to-organ ratios. These results showed that 64Cu-PSMA-CM was PSMA specific with a higher tumor uptake, which demonstrated that MPA is an optional strategy for improving the radioactivity concentration in PSMA-expressing tumors and for developing the ligands for PSMA radioligand therapy.
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Affiliation(s)
- Ya’nan Ren
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Key Laboratory for Research and Evaluation of Radiopharmaceuticals (National Medical Products Administration), Department of Nuclear Medicine, Peking University Cancer Hospital & Institute, Beijing 100142, China; (Y.R.); (T.L.); (C.L.); (X.G.); (F.W.)
- School of Medicine, Guizhou University, Guiyang 550025, China
| | - Teli Liu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Key Laboratory for Research and Evaluation of Radiopharmaceuticals (National Medical Products Administration), Department of Nuclear Medicine, Peking University Cancer Hospital & Institute, Beijing 100142, China; (Y.R.); (T.L.); (C.L.); (X.G.); (F.W.)
| | - Chen Liu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Key Laboratory for Research and Evaluation of Radiopharmaceuticals (National Medical Products Administration), Department of Nuclear Medicine, Peking University Cancer Hospital & Institute, Beijing 100142, China; (Y.R.); (T.L.); (C.L.); (X.G.); (F.W.)
| | - Xiaoyi Guo
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Key Laboratory for Research and Evaluation of Radiopharmaceuticals (National Medical Products Administration), Department of Nuclear Medicine, Peking University Cancer Hospital & Institute, Beijing 100142, China; (Y.R.); (T.L.); (C.L.); (X.G.); (F.W.)
| | - Feng Wang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Key Laboratory for Research and Evaluation of Radiopharmaceuticals (National Medical Products Administration), Department of Nuclear Medicine, Peking University Cancer Hospital & Institute, Beijing 100142, China; (Y.R.); (T.L.); (C.L.); (X.G.); (F.W.)
| | - Hua Zhu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Key Laboratory for Research and Evaluation of Radiopharmaceuticals (National Medical Products Administration), Department of Nuclear Medicine, Peking University Cancer Hospital & Institute, Beijing 100142, China; (Y.R.); (T.L.); (C.L.); (X.G.); (F.W.)
- School of Medicine, Guizhou University, Guiyang 550025, China
- Correspondence: (H.Z.); (Z.Y.)
| | - Zhi Yang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Key Laboratory for Research and Evaluation of Radiopharmaceuticals (National Medical Products Administration), Department of Nuclear Medicine, Peking University Cancer Hospital & Institute, Beijing 100142, China; (Y.R.); (T.L.); (C.L.); (X.G.); (F.W.)
- School of Medicine, Guizhou University, Guiyang 550025, China
- Correspondence: (H.Z.); (Z.Y.)
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20
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Neels OC, Kopka K, Liolios C, Afshar-Oromieh A. Radiolabeled PSMA Inhibitors. Cancers (Basel) 2021; 13:6255. [PMID: 34944875 PMCID: PMC8699044 DOI: 10.3390/cancers13246255] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 12/10/2021] [Accepted: 12/11/2021] [Indexed: 12/16/2022] Open
Abstract
PSMA has shown to be a promising target for diagnosis and therapy (theranostics) of prostate cancer. We have reviewed developments in the field of radio- and fluorescence-guided surgery and targeted photodynamic therapy as well as multitargeting PSMA inhibitors also addressing albumin, GRPr and integrin αvβ3. An overview of the regulatory status of PSMA-targeting radiopharmaceuticals in the USA and Europe is also provided. Technical and quality aspects of PSMA-targeting radiopharmaceuticals are described and new emerging radiolabeling strategies are discussed. Furthermore, insights are given into the production, application and potential of alternatives beyond the commonly used radionuclides for radiolabeling PSMA inhibitors. An additional refinement of radiopharmaceuticals is required in order to further improve dose-limiting factors, such as nephrotoxicity and salivary gland uptake during endoradiotherapy. The improvement of patient treatment achieved by the advantageous combination of radionuclide therapy with alternative therapies is also a special focus of this review.
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Affiliation(s)
- Oliver C. Neels
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Bautzner Landstrasse 400, 01328 Dresden, Germany;
| | - Klaus Kopka
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Bautzner Landstrasse 400, 01328 Dresden, Germany;
- Faculty of Chemistry and Food Chemistry, School of Science, Technical University Dresden, Mommsenstrasse 4, 01062 Dresden, Germany
| | - Christos Liolios
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, National & Kapodistrian University of Athens, Zografou, 15771 Athens, Greece;
- INRASTES, Radiochemistry Laboratory, NCSR “Demokritos”, Ag. Paraskevi Attikis, 15310 Athens, Greece
| | - Ali Afshar-Oromieh
- Department of Nuclear Medicine, Bern University Hospital (Inselspital), Freiburgstrasse 18, 3010 Bern, Switzerland;
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21
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Lee BS, Kim MH, Chu SY, Jung WJ, Jeong HJ, Lee K, Kim HS, Kim MH, Kil HS, Han SJ, Lee YJ, Lee KC, Lim SM, Chi DY. Improving Theranostic Gallium-68/Lutetium-177-Labeled PSMA Inhibitors with an Albumin Binder for Prostate Cancer. Mol Cancer Ther 2021; 20:2410-2419. [PMID: 34725194 DOI: 10.1158/1535-7163.mct-21-0251] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 07/21/2021] [Accepted: 09/29/2021] [Indexed: 11/16/2022]
Abstract
We developed a novel therapeutic radioligand, [177Lu]1h, with an albumin binding motif and evaluated it in a prostate-specific membrane antigen (PSMA)-expressing tumor xenograft mouse model. Fourteen PSMA target candidates were synthesized, and binding affinity was evaluated with an in vitro competitive binding assay. First, four compound candidates were selected depending on binding affinity results. Next, we selected four compounds ([68Ga]1e, [68Ga]1g, [68Ga]1h, and [68Ga]1k) were screened for tumor targeting efficiency by micro-positron emission tomography/computed tomography (micro-PET/CT) imaging. Finally, [177Lu]1h compound was evaluated the tumor targeting efficiency and therapeutic efficiency by micro-single-photon emission computed tomography/computed tomography (micro-SPECT/CT), biodistribution, and radiotherapy studies. Estimated human effective dose was calculated by biodistribution data. Compound 1h showed a high binding affinity (Ki value = 4.08 ± 0.08 nmol/L), and [177Lu]1h showed extended blood circulation (1 hour = 10.32 ± 0.31, 6 hours = 2.68 ± 1.07%ID/g) compared to [177Lu]PSMA-617 (1 h = 0.17 ± 0.10%ID/g). [177Lu]1h was excreted via the renal pathway and showed high tumor uptake (24.43 ± 3.36%ID/g) after 1 hour, which increased over 72 hours (72 hours = 51.39 ± 9.26%ID/g). Mice treated with 4 and 6 MBq of [177Lu]1h showed a median survival rate of >61 days. In particular, all mice treated with 6 MBq of [177Lu]1h survived for the entire monitoring period. The estimated human effective dose of [177Lu]1h was 0.07 ± 0.01 and 0.03 ± 0.00 mSv/MBq in total body and kidney, respectively. The current study indicates that [177Lu]1h has the potential for further investigation of metastatic castration-resistant prostate cancer (mCRPC) therapy in clinical trials.
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Affiliation(s)
- Byoung Se Lee
- Research Institute of Labeling, FutureChem Co., Ltd., Seoul, Republic of Korea
| | - Min Hwan Kim
- Research Institute of Labeling, FutureChem Co., Ltd., Seoul, Republic of Korea
| | - So Young Chu
- Research Institute of Labeling, FutureChem Co., Ltd., Seoul, Republic of Korea
| | - Woon Jung Jung
- Research Institute of Labeling, FutureChem Co., Ltd., Seoul, Republic of Korea
| | - Hyeon Jin Jeong
- Research Institute of Labeling, FutureChem Co., Ltd., Seoul, Republic of Korea
| | - Kyongkyu Lee
- Research Institute of Labeling, FutureChem Co., Ltd., Seoul, Republic of Korea
| | - Hyeon Seok Kim
- Research Institute of Labeling, FutureChem Co., Ltd., Seoul, Republic of Korea
| | - Mi Hyun Kim
- Research Institute of Labeling, FutureChem Co., Ltd., Seoul, Republic of Korea
| | - Hee Seup Kil
- Research Institute of Labeling, FutureChem Co., Ltd., Seoul, Republic of Korea
| | - Sang Jin Han
- Division of Applied RI, Korea Institute of Radiological & Medical Sciences, Seoul, Republic of Korea
| | - Yong Jin Lee
- Division of Applied RI, Korea Institute of Radiological & Medical Sciences, Seoul, Republic of Korea
| | - Kyo Chul Lee
- Division of Applied RI, Korea Institute of Radiological & Medical Sciences, Seoul, Republic of Korea
| | - Sang Moo Lim
- Department of Nuclear Medicine, Korea Institute of Radiological & Medical Sciences, Seoul, Republic of Korea
| | - Dae Yoon Chi
- Research Institute of Labeling, FutureChem Co., Ltd., Seoul, Republic of Korea.
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22
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Iikuni S, Tarumizu Y, Nakashima K, Higaki Y, Ichikawa H, Watanabe H, Ono M. Radiotheranostics Using a Novel 225Ac-Labeled Radioligand with Improved Pharmacokinetics Targeting Prostate-Specific Membrane Antigen. J Med Chem 2021; 64:13429-13438. [PMID: 34477385 DOI: 10.1021/acs.jmedchem.1c00772] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
225Ac-based radiotheranostics targeting prostate-specific membrane antigen (PSMA) has induced impressive responses in patients with metastatic castration-resistant prostate cancer. To enhance the therapeutic effects of radioligands labeled with 225Ac (half-life: 10 days), a radioligand that shows longer tumor retention would be useful. Here, we designed and synthesized a straight-chain PSMA-targeting radioligand, PSMA-DA1, which includes an (iodophenyl)butyric acid derivative as an albumin binder (ALB). We performed preclinical evaluations of PSMA-DA1 as a tool for PSMA-targeting radiotheranostics using 111In, 90Y, and 225Ac. [111In]In-PSMA-DA1 demonstrated significantly greater tumor uptake and retention than a corresponding non-ALB-conjugated compound. In mice, single-photon emission computed tomography performed with [111In]In-PSMA-DA1 produced clear tumor images, and the administration of [90Y]Y-PSMA-DA1 or [225Ac]Ac-PSMA-DA1 inhibited tumor growth. [225Ac]Ac-PSMA-DA1 had antitumor effects in mice at a lower radioactivity level than [225Ac]Ac-PSMA-617, which has been reported to be clinically useful. These results indicate that PSMA-DA1 may be a useful PSMA-targeting radiotheranostic agent.
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Affiliation(s)
- Shimpei Iikuni
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Yuta Tarumizu
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Kazuma Nakashima
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Yusuke Higaki
- Nihon Medi-Physics Co., Ltd., 3-4-10 Shinsuna, Koto-ku, Tokyo 136-0075, Japan
| | - Hiroaki Ichikawa
- Nihon Medi-Physics Co., Ltd., 3-4-10 Shinsuna, Koto-ku, Tokyo 136-0075, Japan
| | - Hiroyuki Watanabe
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Masahiro Ono
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan
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23
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Impact of the mouse model and molar amount of injected ligand on the tissue distribution profile of PSMA radioligands. Eur J Nucl Med Mol Imaging 2021; 49:470-480. [PMID: 34402925 PMCID: PMC8803738 DOI: 10.1007/s00259-021-05446-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 06/02/2021] [Indexed: 12/26/2022]
Abstract
Purpose Various preclinical study designs are described in the literature for the evaluation of PSMA radioligands. In this study, [177Lu]Lu-Ibu-DAB-PSMA, an albumin-binding radioligand, and [177Lu]Lu-PSMA-617 were investigated and compared under variable experimental conditions. Methods In vitro cell uptake studies were performed with PC-3 PIP and LNCaP tumor cells using a range of molar concentrations (0.75–500 nM) of both radioligands. Biodistribution and SPECT/CT imaging studies were carried out with the respective tumor mouse models using 0.05 nmol and 1.0 nmol injected ligand per mouse. Results In both tumor cell lines, the uptake of the radioligands was increased when using low molar concentrations of the respective ligand. The observed saturation effect at high ligand concentrations was more pronounced for LNCaP cells that express PSMA at lower levels than for PC-3 PIP cells. At all investigated timepoints, the in vivo uptake of both radioligands was higher in PC-3 PIP tumors than in LNCaP tumors. A low molar amount of injected ligand increased the PC-3 PIP tumor uptake mainly for [177Lu]Lu-Ibu-DAB-PSMA; however, the molar amount of ligand was relevant for both radioligands when using LNCaP tumors. Renal retention of both radioligands was, however, up to fourfold higher during the first hours after application of a low ligand amount compared to the high ligand amount. Conclusion The results of this preclinical study underline the relevance of the tumor model and applied ligand amount for the characterization of PSMA radioligands. The application of equal preclinical study designs is crucial to allow the comparison of novel radioligands with existing ones and, thus, predict potential advantages of new radioligands in view of a clinical application. Supplementary Information The online version contains supplementary material available at 10.1007/s00259-021-05446-5.
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24
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Parsi M, Desai MH, Desai D, Singhal S, Khandwala PM, Potdar RR. PSMA: a game changer in the diagnosis and treatment of advanced prostate cancer. Med Oncol 2021; 38:89. [PMID: 34181109 DOI: 10.1007/s12032-021-01537-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 06/15/2021] [Indexed: 12/13/2022]
Abstract
Although management of advanced prostate cancer is evolving, a lot of work remains to be done for patients who have exhausted all options. Molecular targeting of prostate specific membrane antigen (PSMA) is valuable not only for diagnostic but also for therapeutic reasons. PSMA is thus considered to be useful in a theranostic approach. PSMA scans are upcoming diagnostic modalities which detect metastatic lesions that are missed by conventional imaging modalities. PSMA ligand therapy is also an upcoming treatment modality that has been proven to be beneficial with minimal toxicity in patients with advanced prostate cancer that have progressed on prior therapy. In this review article, we summarize the current knowledge regarding PSMA diagnostics and PSMA ligand therapies and discuss their implication in the treatment of advanced prostate cancer.
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Affiliation(s)
- Meghana Parsi
- Dept of Internal Medicine, Crozer-Chester Medical Center, 1 Medical Center Blvd, Upland, PA, USA.
| | - Milap H Desai
- Drexel University College of Medicine, Philadelphia, PA, USA
| | - Devashish Desai
- Dept of Internal Medicine, Crozer-Chester Medical Center, 1 Medical Center Blvd, Upland, PA, USA
| | - Sachi Singhal
- Dept of Internal Medicine, Crozer-Chester Medical Center, 1 Medical Center Blvd, Upland, PA, USA
| | - Pushti M Khandwala
- Dept of Internal Medicine, Crozer-Chester Medical Center, 1 Medical Center Blvd, Upland, PA, USA
| | - Rashmika R Potdar
- Dept of Hematology Oncology, Crozer-Chester Medical Center, Upland, PA, USA
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25
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Stenberg VY, Larsen RH, Ma LW, Peng Q, Juzenas P, Bruland ØS, Juzeniene A. Evaluation of the PSMA-Binding Ligand 212Pb-NG001 in Multicellular Tumour Spheroid and Mouse Models of Prostate Cancer. Int J Mol Sci 2021; 22:ijms22094815. [PMID: 34062920 PMCID: PMC8124365 DOI: 10.3390/ijms22094815] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/27/2021] [Accepted: 04/29/2021] [Indexed: 01/12/2023] Open
Abstract
Radioligand therapy targeting the prostate-specific membrane antigen (PSMA) is rapidly evolving as a promising treatment for metastatic castration-resistant prostate cancer. The PSMA-targeting ligand p-SCN-Bn-TCMC-PSMA (NG001) labelled with 212Pb efficiently targets PSMA-positive cells in vitro and in vivo. The aim of this preclinical study was to evaluate the therapeutic potential of 212Pb-NG001 in multicellular tumour spheroid and mouse models of prostate cancer. The cytotoxic effect of 212Pb-NG001 was tested in human prostate C4-2 spheroids. Biodistribution at various time points and therapeutic effects of different activities of the radioligand were investigated in male athymic nude mice bearing C4-2 tumours, while long-term toxicity was studied in immunocompetent BALB/c mice. The radioligand induced a selective cytotoxic effect in spheroids at activity concentrations of 3–10 kBq/mL. In mice, the radioligand accumulated rapidly in tumours and was retained over 24 h, while it rapidly cleared from nontargeted tissues. Treatment with 0.25, 0.30 or 0.40 MBq of 212Pb-NG001 significantly inhibited tumour growth and improved median survival with therapeutic indexes of 1.5, 2.3 and 2.7, respectively. In BALB/c mice, no signs of long-term radiation toxicity were observed at activities of 0.05 and 0.33 MBq. The obtained results warrant clinical studies to evaluate the biodistribution, therapeutic efficacy and toxicity of 212Pb-NG001.
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Affiliation(s)
- Vilde Yuli Stenberg
- Department of Radiation Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, 0379 Oslo, Norway; (L.-W.M.); (A.J.)
- Department of Research and Development, Nucligen AS, 0379 Oslo, Norway;
- Institute for Clinical Medicine, University of Oslo, 0318 Oslo, Norway;
- Correspondence: ; Tel.: +47-9012-8434
| | | | - Li-Wei Ma
- Department of Radiation Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, 0379 Oslo, Norway; (L.-W.M.); (A.J.)
| | - Qian Peng
- Department of Pathology, The Norwegian Radium Hospital, Oslo University Hospital, 0379 Oslo, Norway; (Q.P.); (P.J.)
| | - Petras Juzenas
- Department of Pathology, The Norwegian Radium Hospital, Oslo University Hospital, 0379 Oslo, Norway; (Q.P.); (P.J.)
| | - Øyvind Sverre Bruland
- Institute for Clinical Medicine, University of Oslo, 0318 Oslo, Norway;
- Department of Oncology, The Norwegian Radium Hospital, Oslo University Hospital, 0379 Oslo, Norway
| | - Asta Juzeniene
- Department of Radiation Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, 0379 Oslo, Norway; (L.-W.M.); (A.J.)
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Kelly JM, Jeitner TM, Ponnala S, Williams C, Nikolopoulou A, DiMagno SG, Babich JW. A Trifunctional Theranostic Ligand Targeting Fibroblast Activation Protein-α (FAPα). Mol Imaging Biol 2021; 23:686-696. [PMID: 33721173 DOI: 10.1007/s11307-021-01593-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 01/05/2021] [Accepted: 02/16/2021] [Indexed: 12/13/2022]
Abstract
PURPOSE Fibroblast activation protein-α (FAPα) is uniquely expressed in activated fibroblasts, including cancer-associated fibroblasts that populate tumor stroma and contribute to proliferation and immunosuppression. Radiolabeled FAPα inhibitors enable imaging of multiple human cancers, but time-dependent clearance from tumors currently limits their utility as FAPα-targeted radiotherapeutics. We sought to increase the area under the curve (AUC) by constructing a trifunctional ligand that binds FAPα with high affinity and also binds albumin and theranostic radiometals. PROCEDURES RPS-309 comprised a FAPα-targeting moiety, an albumin-binding group, and 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA). Inhibition of recombinant human FAPα (rhFAPα) was determined by colorimetric assay. Affinity for human serum albumin (HSA) was determined by high-performance affinity chromatography. The tissue distribution of [68Ga]Ga-RPS-309 in SW872 tumor xenograft-bearing mice was imaged by microPET/CT and quantified by biodistribution studies performed from 30 min to 3 h post injection (p.i.). The biodistribution of [177Lu]Lu-RPS-309 was determined at 4, 24, and 96 h p.i. RESULTS RPS-309 inhibits rhFAPα with IC50 = 7.3 ± 1.4 nM. [68Ga]Ga-RPS-309 is taken up specifically by FAPα-expressing cells and binds HSA with Kd = 4.6 ± 0.1 μM. Uptake of the radiolabeled ligand in tumors was evident from 30 min p.i. (> 5 %ID/g) and was significantly reduced by co-injection of RPS-309. Specific skeletal uptake was also observed. Activity in tumors was constant through 4 h p.i., but cleared significantly by 24 h. The AUC in this period was 127 (%ID/g) × h. CONCLUSIONS RPS-309 is a high-affinity FAPα inhibitor with prolonged plasma residence. Introduction of the albumin-binding group did not compromise FAPα binding. Although initial tumor uptake was high and FAPα-specific, RPS-309 also progressively cleared from tumors. Nevertheless, RPS-309 incorporates multiple sites in which structural diversity can be introduced, and therefore serves as a platform for future structure-activity relationship studies.
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Affiliation(s)
- James M Kelly
- Molecular Imaging Innovations Institute (MI3), Department of Radiology, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Thomas M Jeitner
- Molecular Imaging Innovations Institute (MI3), Department of Radiology, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Shashikanth Ponnala
- Molecular Imaging Innovations Institute (MI3), Department of Radiology, Weill Cornell Medicine, New York, NY, 10065, USA
- Angion Biomedica Corp., Uniondale, NY, 11553, USA
| | - Clarence Williams
- Molecular Imaging Innovations Institute (MI3), Department of Radiology, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Anastasia Nikolopoulou
- Molecular Imaging Innovations Institute (MI3), Department of Radiology, Weill Cornell Medicine, New York, NY, 10065, USA
- Citigroup Biomedical Imaging Center, Weill Cornell Medicine, New York, NY, 10021, USA
- The Janssen Pharmaceutical Companies of Johnson & Johnson, Spring House, PA, 19477, USA
| | - Stephen G DiMagno
- Departments of Pharmaceutical Sciences and Chemistry, UIC College of Pharmacy, Chicago, IL, USA
| | - John W Babich
- Molecular Imaging Innovations Institute (MI3), Department of Radiology, Weill Cornell Medicine, New York, NY, 10065, USA.
- Citigroup Biomedical Imaging Center, Weill Cornell Medicine, New York, NY, 10021, USA.
- Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, New York, NY, 10065, USA.
- Department of Radiology, Weill Cornell Medicine, Belfer Research Building, Room 1600, 413 E 69th St, New York, NY, 10021, USA.
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Preclinical Dosimetry, Imaging, and Targeted Radionuclide Therapy Studies of Lu-177-Labeled Albumin-Binding, PSMA-Targeted CTT1403. Mol Imaging Biol 2021; 22:274-284. [PMID: 31321650 PMCID: PMC6980512 DOI: 10.1007/s11307-019-01404-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
PURPOSE Prostate-specific membrane antigen (PSMA) continues to be the hallmark biomarker for prostate cancer as it is expressed on nearly all prostatic tumors. In addition, increased PSMA expression correlates with castration resistance and progression to the metastatic stage of the disease. Recently, we combined both an albumin-binding motif and an irreversible PSMA inhibitor to develop the novel PSMA-targeted radiotherapeutic agent, CTT1403. This molecule was novel in the field of PSMA-targeted agents as its key motifs resulted in extended blood circulation time and tumor uptake, rapid and extensive internalization into PSMA+ cells, and promising therapeutic efficacy. The objective of this study was to perform IND-enabling translational studies on CTT1403 in rodent models. PROCEDURES A dose optimization study was performed in PC3-PIP (PSMA+) tumor-bearing mice. Treatment groups were randomly selected to receive one to three 14-MBq injections of CTT1403. Control groups included (1) saline, (2) non-radioactive [175Lu]CTT1403, or (3) two injections of 14 MBq CTT1751, a Lu-177-labeled non-targeted albumin-binding moiety. Tumor growth was monitored up to 120 days. Small-animal single photon emission tomography/X-ray computed tomography imaging was performed with CTT1403 and CTT1751 in PC3-PIP tumor-bearing mice to visualize infiltration of the Lu-177-labeled agent into the tumor. In preparation for a first-in-human study, human absorbed doses were estimated based on rat biodistribution out to 5 weeks to determine a safe CTT1403 therapy dose in humans. RESULTS Two to 3 injections of 14 MBq CTT1403 yielded significant tumor growth inhibition and increased survival compared with all control groups and mice receiving 1 injection of 14 MBq CTT1403. Five of 12 mice receiving 2 or 3 injections of CTT1403 survived to the 120-day post-treatment study endpoint. Dosimetry identified the kidneys as the dose-limiting organ, with an equivalent dose of 5.18 mSv/MBq, resulting in a planned maximum dose of 4.4 GBq for phase 1 clinical trials. CONCLUSIONS The preclinical efficacy and dosimetry of CTT1403 suggest that this agent has significant potential to be safe and effective in humans.
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Miyahira AK, Pienta KJ, Babich JW, Bander NH, Calais J, Choyke P, Hofman MS, Larson SM, Lin FI, Morris MJ, Pomper MG, Sandhu S, Scher HI, Tagawa ST, Williams S, Soule HR. Meeting report from the Prostate Cancer Foundation PSMA theranostics state of the science meeting. Prostate 2020; 80:1273-1296. [PMID: 32865839 PMCID: PMC8442561 DOI: 10.1002/pros.24056] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 07/23/2020] [Indexed: 12/12/2022]
Abstract
INTRODUCTION The Prostate Cancer Foundation (PCF) convened a PCF prostate-specific membrane antigen (PSMA) Theranostics State of the Science Meeting on 18 November 2019, at Weill Cornell Medicine, New York, NY. METHODS The meeting was attended by 22 basic, translational, and clinical researchers from around the globe, with expertise in PSMA biology, development and use of PSMA theranostics agents, and clinical trials. The goal of this meeting was to discuss the current state of knowledge, the most important biological and clinical questions, and critical next steps for the clinical development of PSMA positron emission tomography (PET) imaging agents and PSMA-targeted radionuclide agents for patients with prostate cancer. RESULTS Several major topic areas were discussed including the biology of PSMA, the role of PSMA-targeted PET imaging in prostate cancer, the physics and performance of different PSMA-targeted PET imaging agents, the current state of clinical development of PSMA-targeted radionuclide therapy (RNT) agents, the role of dosimetry in PSMA RNT treatment planning, barriers and challenges in PSMA RNT clinical development, optimization of patient selection for PSMA RNT trials, and promising combination treatment approaches with PSMA RNT. DISCUSSION This article summarizes the presentations from the meeting for the purpose of globally disseminating this knowledge to advance the use of PSMA-targeted theranostic agents for imaging and treatment of patients with prostate cancer.
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Affiliation(s)
- Andrea K. Miyahira
- Science Department, Prostate Cancer Foundation, Santa Monica, California
| | - Kenneth J. Pienta
- Department of Urology, The Brady Urological Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - John W. Babich
- Department of Radiology, Weill Cornell Medicine, New York, New York
| | - Neil H. Bander
- Laboratory of Urologic Oncology, Department of Urology and Meyer Cancer Center, Weill Cornell Medicine, New York, New York
| | - Jeremie Calais
- Ahmanson Translational Theranostics Division, Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
| | - Peter Choyke
- Molecular Imaging Program, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland
| | - Michael S. Hofman
- Prostate Cancer Theranostics and Imaging Centre of Excellence (ProsTIC), Peter MacCallum Cancer Centre, The University of Melbourne, Melbourne, Australia
- Department of Molecular Imaging and Therapeutic Nuclear Medicine, Peter MacCallum Cancer Centre, The University of Melbourne, Melbourne, Australia
| | - Steven M. Larson
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Frank I. Lin
- Molecular Imaging Program, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland
| | - Michael J. Morris
- Genitourinary Oncology Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Martin G. Pomper
- Department of Urology, The Brady Urological Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Shahneen Sandhu
- Prostate Cancer Theranostics and Imaging Centre of Excellence (ProsTIC), Peter MacCallum Cancer Centre, The University of Melbourne, Melbourne, Australia
- Department of Medical Oncology, Peter MacCallum Cancer Centre, The University of Melbourne, Melbourne, Australia
| | - Howard I. Scher
- Genitourinary Oncology Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York
- Department of Medicine, Weill Cornell Medical College, New York, New York
| | - Scott T. Tagawa
- Division of Hematology and Medical Oncology, Department of Medicine, Weill Cornell Medicine, New York, New York
| | - Scott Williams
- Prostate Cancer Theranostics and Imaging Centre of Excellence (ProsTIC), Peter MacCallum Cancer Centre, The University of Melbourne, Melbourne, Australia
- Department of Radiation Oncology, Peter MacCallum Cancer Centre, The University of Melbourne, Melbourne, Australia
| | - Howard R. Soule
- Science Department, Prostate Cancer Foundation, Santa Monica, California
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Garousi J, von Witting E, Borin J, Vorobyeva A, Altai M, Vorontsova O, Konijnenberg MW, Oroujeni M, Orlova A, Tolmachev V, Hober S. Radionuclide therapy using ABD-fused ADAPT scaffold protein: Proof of Principle. Biomaterials 2020; 266:120381. [PMID: 33120197 DOI: 10.1016/j.biomaterials.2020.120381] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 08/31/2020] [Accepted: 09/10/2020] [Indexed: 01/18/2023]
Abstract
Molecular recognition in targeted therapeutics is typically based on immunoglobulins. Development of engineered scaffold proteins (ESPs) has provided additional opportunities for the development of targeted therapies. ESPs offer inexpensive production in prokaryotic hosts, high stability and convenient approaches to modify their biodistribution. In this study, we demonstrated successful modification of the biodistribution of an ESP known as ADAPT (Albumin-binding domain Derived Affinity ProTein). ADAPTs are selected from a library based on the scaffold of ABD (Albumin Binding Domain) of protein G. A particular ADAPT, the ADAPT6, binds to human epidermal growth factor receptor type 2 (HER2) with high affinity. Preclinical and early clinical studies have demonstrated that radiolabeled ADAPT6 can image HER2-expression in tumors with high contrast. However, its rapid glomerular filtration and high renal reabsorption have prevented its use in radionuclide therapy. To modify the biodistribution, ADAPT6 was genetically fused to an ABD. The non-covalent binding to the host's albumin resulted in a 14-fold reduction of renal uptake and appreciable increase of tumor uptake for the best variant, 177Lu-DOTA-ADAPT6-ABD035. Experimental therapy in mice bearing HER2-expressing xenografts demonstrated more than two-fold increase of median survival even after a single injection of 18 MBq 177Lu-DOTA-ADAPT6-ABD035. Thus, a fusion with ABD and optimization of the molecular design provides ADAPT derivatives with attractive targeting properties for radionuclide therapy.
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Affiliation(s)
- Javad Garousi
- Department of Immunology, Genetics and Pathology, Uppsala University, SE-75185, Uppsala, Sweden
| | - Emma von Witting
- Department of Protein Technology, KTH-Royal Institute of Technology, SE-10691, Stockholm, Sweden
| | - Jesper Borin
- Department of Protein Technology, KTH-Royal Institute of Technology, SE-10691, Stockholm, Sweden
| | - Anzhelika Vorobyeva
- Department of Immunology, Genetics and Pathology, Uppsala University, SE-75185, Uppsala, Sweden; Research Centrum for Oncotheranostics, Research School of Chemistry and Applied Biomedical Sciences, Research Tomsk Polytechnic University, Tomsk, Russia
| | - Mohamed Altai
- Department of Immunology, Genetics and Pathology, Uppsala University, SE-75185, Uppsala, Sweden
| | - Olga Vorontsova
- Department of Immunology, Genetics and Pathology, Uppsala University, SE-75185, Uppsala, Sweden
| | - Mark W Konijnenberg
- Department of Radiology and Nuclear Medicine, Erasmus MC, Rotterdam, the Netherlands
| | - Maryam Oroujeni
- Department of Immunology, Genetics and Pathology, Uppsala University, SE-75185, Uppsala, Sweden
| | - Anna Orlova
- Research Centrum for Oncotheranostics, Research School of Chemistry and Applied Biomedical Sciences, Research Tomsk Polytechnic University, Tomsk, Russia; Department of Medicinal Chemistry, Uppsala University, Uppsala, Sweden; Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Vladimir Tolmachev
- Department of Immunology, Genetics and Pathology, Uppsala University, SE-75185, Uppsala, Sweden; Research Centrum for Oncotheranostics, Research School of Chemistry and Applied Biomedical Sciences, Research Tomsk Polytechnic University, Tomsk, Russia.
| | - Sophia Hober
- Department of Protein Technology, KTH-Royal Institute of Technology, SE-10691, Stockholm, Sweden
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Biodistribution and dosimetry of a single dose of albumin-binding ligand [ 177Lu]Lu-PSMA-ALB-56 in patients with mCRPC. Eur J Nucl Med Mol Imaging 2020; 48:893-903. [PMID: 32949253 PMCID: PMC8036212 DOI: 10.1007/s00259-020-05022-3] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 08/31/2020] [Indexed: 12/11/2022]
Abstract
Introduction PSMA-targeted radionuclide therapy with lutetium-177 has emerged as an effective treatment option for metastatic, castration-resistant prostate cancer (mCRPC). Recently, the concept of modifying PSMA radioligands with an albumin-binding entity was demonstrated as a promising measure to increase the tumor uptake in preclinical experiments. The aim of this study was to translate the concept to a clinical setting and evaluate the safety and dosimetry of [177Lu]Lu-PSMA-ALB-56, a novel PSMA radioligand with albumin-binding properties. Methods Ten patients (71.8 ± 8.2 years) with mCRPC received an activity of 3360 ± 393 MBq (120–160 μg) [177Lu]Lu-PSMA-ALB-56 followed by whole-body SPECT/CT imaging over 7 days. Volumes of interest were defined on the SPECT/CT images for dosimetric evaluation for healthy tissue and tumor lesions. General safety and therapeutic efficacy were assessed by measuring blood biomarkers. Results [177Lu]Lu-PSMA-ALB-56 was well tolerated, and no severe adverse events were observed. SPECT images revealed longer circulation of [177Lu]Lu-PSMA-ALB-56 in the blood with the highest uptake in tumor lesions at 48 h post injection. Compared with published data for other therapeutic PSMA radioligands (e.g. PSMA-617 and PSMA I&T), normalized absorbed doses of [177Lu]Lu-PSMA-ALB-56 were up to 2.3-fold higher in tumor lesions (6.64 ± 6.92 Gy/GBq) and similar in salivary glands (0.87 ± 0.43 Gy/GBq). Doses to the kidneys and red marrow (2.54 ± 0.94 Gy/GBq and 0.29 ± 0.07 Gy/GBq, respectively) were increased. Conclusion Our data demonstrated that the concept of albumin-binding PSMA-radioligands is feasible and leads to increased tumor doses. After further optimization of the ligand design, the therapeutic outcomes may be improved for patients with prostate cancer. Electronic supplementary material The online version of this article (10.1007/s00259-020-05022-3) contains supplementary material, which is available to authorized users.
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31
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Kuo HT, Lin KS, Zhang Z, Uribe CF, Merkens H, Zhang C, Bénard F. 177Lu-Labeled Albumin-Binder-Conjugated PSMA-Targeting Agents with Extremely High Tumor Uptake and Enhanced Tumor-to-Kidney Absorbed Dose Ratio. J Nucl Med 2020; 62:521-527. [PMID: 32859704 DOI: 10.2967/jnumed.120.250738] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 07/29/2020] [Indexed: 12/22/2022] Open
Abstract
The use of an albumin binder has been shown to improve tumor uptake of prostate-specific membrane antigen (PSMA)-targeting radiotherapeutic agents. The aim of this study was to develop improved radiotherapeutic agents that combine an optimized affinity-modifying group and optimized albumin binders to maximize the tumor-to-kidney absorbed dose ratio. Methods: 68Ga-labeled DOTA-conjugated lysine-ureido-glutamate-based PSMA-targeting agents bearing various affinity-modifying groups or albumin binders were synthesized and evaluated by PET/CT imaging and biodistribution studies in LNCaP tumor-bearing mice. The optimized affinity-modifying group and albumin binders were combined, and the resulting derivatives were radiolabeled with 177Lu and evaluated by SPECT/CT imaging and biodistribution studies in LNCaP tumor-bearing mice. Radiation dosimetry was calculated using the OLINDA/EXM software. Results: Affinity-modifying group optimization revealed that 68Ga-HTK03041 bearing a tranexamic acid-9-anthrylalanine affinity-modifying group had the highest tumor uptake (23.1 ± 6.11 percentage injected dose [%ID]/g at 1 h after injection). Albumin binder optimization showed that 68Ga-HTK03055 and 68Ga-HTK03086 bearing the N-(4-(p-chlorophenyl)butanoyl)-Gly and N-(4-(p-methoxyphenyl)butanoyl)-Gly motifs, respectively, had relatively faster tumor accumulation (∼30 %ID/g at 3 h after injection) and lower average kidney uptake (<55 %ID/g at both 1 and 3 h after injection). Combining the tranexamic acid-9-anthrylalanine affinity-modifying group with N-(4-(p-chlorophenyl)butanoyl)-Gly and N-(4-(p-methoxyphenyl)butanoyl)-Gly albumin-binding motifs generated HTK03121 and HTK03123, respectively. 177Lu-HTK03121 and 177Lu-HTK03123 had extremely high peak uptake (104 ± 20.3 and 70.8 ± 23.7 %ID/g, respectively) in LNCaP tumor xenografts, and this peak was sustained up to 120 h after injection. Dosimetry calculation showed that compared with 177Lu-PSMA-617, 177Lu-HTK03121 and 177Lu-HTK03123 delivered 18.7- and 12.7-fold higher absorbed dose to tumor but only 6.4- and 6.3-fold higher absorbed dose to kidneys, leading to 2.9- and 2.0-fold improvement in the tumor-to-kidney absorbed dose ratios. Conclusion: With greatly enhanced tumor uptake and tumor-to-kidney absorbed dose ratio, 177Lu-HTK03121 and 177Lu-HTK03123 have the potential to improve treatment efficacy using significantly lower quantities of 177Lu and are promising candidates for clinical translation to treat metastatic castration-resistant prostate cancer.
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Affiliation(s)
- Hsiou-Ting Kuo
- Department of Molecular Oncology, BC Cancer, Vancouver, British Columbia, Canada
| | - Kuo-Shyan Lin
- Department of Molecular Oncology, BC Cancer, Vancouver, British Columbia, Canada .,Department of Functional Imaging, BC Cancer, Vancouver, British Columbia, Canada; and.,Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Zhengxing Zhang
- Department of Molecular Oncology, BC Cancer, Vancouver, British Columbia, Canada
| | - Carlos F Uribe
- Department of Functional Imaging, BC Cancer, Vancouver, British Columbia, Canada; and
| | - Helen Merkens
- Department of Molecular Oncology, BC Cancer, Vancouver, British Columbia, Canada
| | - Chengcheng Zhang
- Department of Molecular Oncology, BC Cancer, Vancouver, British Columbia, Canada
| | - François Bénard
- Department of Molecular Oncology, BC Cancer, Vancouver, British Columbia, Canada.,Department of Functional Imaging, BC Cancer, Vancouver, British Columbia, Canada; and.,Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada
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Albumin-Binding PSMA Radioligands: Impact of Minimal Structural Changes on the Tissue Distribution Profile. Molecules 2020; 25:molecules25112542. [PMID: 32486054 PMCID: PMC7321364 DOI: 10.3390/molecules25112542] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 05/26/2020] [Accepted: 05/27/2020] [Indexed: 11/24/2022] Open
Abstract
The concept of using ibuprofen as an albumin-binding entity was recently demonstrated by the development of [177Lu]Lu-Ibu-PSMA-01. In the present study, we designed a novel ibuprofen-containing radioligand (Ibu-PSMA-02) with subtle structural changes regarding the linker entity in order to investigate a potential impact on the in vitro and in vivo properties. Ibu-PSMA-02 was prepared using solid-phase synthesis techniques and labeled with lutetium-177. [177Lu]Lu-Ibu-PSMA-02 was evaluated in vitro with regard to its plasma protein-binding properties, PSMA affinity and uptake into PSMA-expressing PC-3 PIP tumor cells. The tissue distribution profile of [177Lu]Lu-Ibu-PSMA-02 was assessed in tumor-bearing mice and dose estimations were performed. The in vitro characteristics of [177Lu]Lu-Ibu-PSMA-02 were similar to those previously obtained for [177Lu]Lu-Ibu-PSMA-01 with respect to plasma protein-binding, PSMA affinity and tumor cell uptake. The in vivo studies revealed, however, an unprecedentedly high uptake of [177Lu]Lu-Ibu-PSMA-02 in PC-3 PIP tumors, resulting in an increased absorbed tumor dose of 7.7 Gy/MBq as compared to 5.1 Gy/MBq calculated for [177Lu]Lu-Ibu-PSMA-01. As a consequence of the high tumor accumulation, [177Lu]Lu-Ibu-PSMA-02 showed higher tumor-to-background ratios than [177Lu]Lu-Ibu-PSMA-01. This study exemplified that smallest structural changes in the linker entity of PSMA radioligands may have a significant impact on their pharmacokinetic profiles and, thus, may be applied as a means for ligand design optimization.
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33
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Borgna F, Deberle LM, Cohrs S, Schibli R, Müller C. Combined Application of Albumin-Binding [177Lu]Lu-PSMA-ALB-56 and Fast-Cleared PSMA Inhibitors: Optimization of the Pharmacokinetics. Mol Pharm 2020; 17:2044-2053. [DOI: 10.1021/acs.molpharmaceut.0c00199] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Francesca Borgna
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, 5232 Villigen-PSI, Switzerland
| | - Luisa M. Deberle
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, 5232 Villigen-PSI, Switzerland
| | - Susan Cohrs
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, 5232 Villigen-PSI, Switzerland
| | - Roger Schibli
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, 5232 Villigen-PSI, Switzerland
- Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland
| | - Cristina Müller
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, 5232 Villigen-PSI, Switzerland
- Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland
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34
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Kelly JM, Ponnala S, Amor-Coarasa A, Zia NA, Nikolopoulou A, Williams C, Schlyer DJ, DiMagno SG, Donnelly PS, Babich JW. Preclinical Evaluation of a High-Affinity Sarcophagine-Containing PSMA Ligand for 64Cu/ 67Cu-Based Theranostics in Prostate Cancer. Mol Pharm 2020; 17:1954-1962. [PMID: 32286841 DOI: 10.1021/acs.molpharmaceut.0c00060] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The application of small molecules targeting prostate-specific membrane antigen (PSMA) has emerged as a highly promising clinical strategy for visualization and treatment of prostate cancer. Ligands that integrate the ability to both quantify the distribution of radioactivity and treat disease through the use of a matched pair of radionuclides have particular value in clinical and regulatory settings. In this study, we describe the development and preclinical evaluation of RPS-085, a ligand that binds PSMA and serum albumin and exploits the 64/67Cu radionuclide pair for prostate cancer theranostics. RPS-085 was synthesized by conjugation of a PSMA-targeting moiety, an Nε-(2-(4-iodophenyl)acetyl)lysine albumin binding group, and a bifunctionalized MeCOSar chelator. The IC50 of the metal-free RPS-085 was determined in a competitive binding assay. The affinity for human serum albumin of the radiolabeled compound was determined by high-performance affinity chromatography. Radiolabeling was performed in NH4OAc buffer at 25 °C. The stability of the radiolabeled compounds was assessed in vitro and in vivo. The biodistribution of [64/67Cu]Cu-RPS-085 was determined following intravenous administration to male BALB/c mice bearing LNCaP tumor xenografts. The radiochemical yields of [64/67Cu]Cu-RPS-085 were nearly quantitative after 20 min. The metal-free complex is a potent inhibitor of PSMA (IC50 = 29 ± 2 nM), and the radiolabeled compound has moderate affinity for human serum albumin (Kd = 9.9 ± 1.7 μM). Accumulation of the tracer in mice was primarily evident in tumor and kidneys. Activity in all other tissues, including blood, was negligible, and the radiolabeled compounds demonstrated high stability in vitro and in vivo. Tumor activity reached a maximum at 4 h post injection (p.i.) and cleared gradually over a period of 96 h. By contrast, activity in the kidney cleared rapidly from 4 to 24 h p.i. As a consequence, by 24 h p.i., the tumor-to-kidney ratio exceeds 2, and the predicted dose to tumors is significantly greater than the dose to kidneys. [64Cu]Cu-RPS-085 combines rapid tissue distribution and clearance with prolonged retention in LNCaP tumor xenografts. The pharmacokinetics should enable radioligand therapy using [67Cu]Cu-RPS-085. By virtue of its rapid kidney clearance, the therapeutic index of [67Cu]Cu-RPS-085 likely compares favorably to its parent structure, [177Lu]Lu-RPS-063, a highly avid PSMA-targeting compound. On this basis, [64/67Cu]Cu-RPS-085 show great promise as PSMA-targeting theranostic ligands for prostate cancer imaging and therapy.
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Affiliation(s)
- James M Kelly
- Division of Radiopharmaceutical Sciences and MI3 Institute, Department of Radiology, Weill Cornell Medicine, New York, New York 10021, United States
| | - Shashikanth Ponnala
- Division of Radiopharmaceutical Sciences and MI3 Institute, Department of Radiology, Weill Cornell Medicine, New York, New York 10021, United States
| | - Alejandro Amor-Coarasa
- Division of Radiopharmaceutical Sciences and MI3 Institute, Department of Radiology, Weill Cornell Medicine, New York, New York 10021, United States
| | - Nicholas A Zia
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Anastasia Nikolopoulou
- Division of Radiopharmaceutical Sciences and MI3 Institute, Department of Radiology, Weill Cornell Medicine, New York, New York 10021, United States.,Citigroup Biomedical Imaging Center, Weill Cornell Medicine, New York, New York 10021, United States
| | - Clarence Williams
- Division of Radiopharmaceutical Sciences and MI3 Institute, Department of Radiology, Weill Cornell Medicine, New York, New York 10021, United States
| | - David J Schlyer
- Brookhaven National Laboratory, Upton, New York 11973, United States.,Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York 11794, United States
| | - Stephen G DiMagno
- College of Pharmacy, University of Illinois-Chicago, Chicago, Illinois 60612, United States
| | - Paul S Donnelly
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - John W Babich
- Division of Radiopharmaceutical Sciences and MI3 Institute, Department of Radiology, Weill Cornell Medicine, New York, New York 10021, United States.,Citigroup Biomedical Imaging Center, Weill Cornell Medicine, New York, New York 10021, United States.,Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, New York, New York 10065, United States
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Synthesis and Evaluation of 99mTc-Tricabonyl Labeled Isonitrile Conjugates for Prostate-Specific Membrane Antigen (PSMA) Image. INORGANICS 2020. [DOI: 10.3390/inorganics8010005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Prostate-specific membrane antigen (PSMA) is a biomarker expressed on the surface of prostate cancer (PCa). In an effort to improve the detection and treatment of PCa, small urea-based PSMA inhibitors have been studied extensively. In the present study, we aimed to develop 99mTc-tricabonyl labeled urea-based PSMA conjugates containing isonitrile (CN-R)-coordinating ligands ([99mTc]Tc-15 and [99mTc]Tc-16). Both the PSMA conjugates were obtained at high radiochemical efficiency (≥98.5%). High in vitro binding affinity was observed for [99mTc]Tc-15 and [99mTc]Tc-16 (Kd = 5.5 and 0.2 nM, respectively) in PSMA-expressing 22Rv1 cells. Tumor xenografts were conducted using 22Rv1 cells and rapid accumulation of [99mTc]Tc-16 (1.87 ± 0.11% ID/g) was observed at 1 h post-injection, which subsequently increased to (2.83 ± 0.26% ID/g) at 4 h post-injection. However, [99mTc]Tc-15 showed moderate tumor uptake (1.48 ± 0.18% ID/g), which decreased at 4 h post-injection (0.81 ± 0.09% ID/g). [99mTc]Tc-16 was excreted from non-targeted tissues with high tumor-to-blood (17:1) and tumor-to-muscle ratio (41:1) at 4 h post-injection at approximately 4 times higher levels than [99mTc]Tc-15. Uptakes of [99mTc]Tc-15 and [99mTc]Tc-16 to PSMA-expressing tumor and tissues were significantly blocked by co-injection of 2-(Phosphonomethyl)-pentandioic acid (2-PMPA), suggesting that their uptakes are mediated by PSMA specifically. Whole-body single photon emission computed tomography imaging of [99mTc]Tc-16 verified the ex vivo biodistribution results and demonstrated clear visualization of tumors and tissues expressing PSMA compared to [99mTc]Tc-15. In conclusion, using [99mTc]Tc-16 rather than [99mTc]Tc-15 may be the preferable because of its relatively high tumor uptake and retention.
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Deberle LM, Benešová M, Umbricht CA, Borgna F, Büchler M, Zhernosekov K, Schibli R, Müller C. Development of a new class of PSMA radioligands comprising ibuprofen as an albumin-binding entity. Am J Cancer Res 2020; 10:1678-1693. [PMID: 32042329 PMCID: PMC6993238 DOI: 10.7150/thno.40482] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 11/08/2019] [Indexed: 01/02/2023] Open
Abstract
Prostate-specific membrane antigen (PSMA)-targeted radioligands have been used for the treatment of metastatic castration-resistant prostate cancer (mCRPC). Recently, albumin-binding PSMA radioligands with enhanced blood circulation were developed to increase the tumor accumulation of activity. The present study aimed at the design, synthesis and preclinical evaluation of a novel class of PSMA-targeting radioligands equipped with ibuprofen as a weak albumin-binding entity in order to improve the pharmacokinetic properties. Methods: Four novel glutamate-urea-based PSMA ligands were synthesized with ibuprofen, conjugated via variable amino acid-based linker entities. The albumin-binding properties of the 177Lu-labeled PSMA ligands were tested in vitro using mouse and human plasma. Affinity of the radioligands to PSMA and cellular uptake and internalization was investigated using PSMA-positive PC-3 PIP and PSMA-negative PC-3 flu tumor cells. The tissue distribution profile of the radioligands was assessed in biodistribution and imaging studies using PC-3 PIP/flu tumor-bearing nude mice. Results: The PSMA ligands were obtained in moderate yields at high purity (>99%). 177Lu-labeling of the ligands was achieved at up to 100 MBq/nmol with >96% radiochemical purity. In vitro assays confirmed high binding of all radioligands to mouse and human plasma proteins and specific uptake and internalization into PSMA-positive PC-3 PIP tumor cells. Biodistribution studies and SPECT/CT scans revealed high accumulation in PC-3 PIP tumors but negligible uptake in PC-3 flu tumor xenografts as well as rapid clearance of activity from background organs and tissues. 177Lu-Ibu-DAB-PSMA, in which ibuprofen was conjugated via a positively-charged diaminobutyric acid (DAB) entity, showed distinguished tumor uptake and the most favorable tumor-to-blood and tumor-to-kidney ratios. Conclusion: The high accumulation of activity in the tumor and fast clearance from background organs was a common favorable characteristic of PSMA radioligands modified with ibuprofen as albumin-binding entity. 177Lu-Ibu-DAB-PSMA emerged as the most promising candidate; hence, more detailed preclinical investigations with this radioligand are warranted in view of a clinical translation.
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Inubushi M, Shidahara M, Takahashi Y, Ogawa M, Kiyono Y. From the respective expert viewpoints of the ANM specialty editors. Ann Nucl Med 2019; 33:877-880. [PMID: 31745811 PMCID: PMC6882778 DOI: 10.1007/s12149-019-01421-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 11/11/2019] [Indexed: 02/07/2023]
Abstract
Although it may not be well known, the Annals of Nuclear Medicine (ANM) Editorial Committee includes one specialty editor of nuclear medicine physics, one of nuclear medicine technology, one of molecular imaging, and two of radiopharmacology. In addition, a statistics editor and a language editor are also on the committee. Manuscripts submitted to ANM can be peer-reviewed by such specialty editors similar to those submitted to highly ranked journals, which is a great pride and joy to us. To offer our readers a condensed global view on the high-quality research work in the field of nuclear medicine, we have published a mini-review article every year under the joint authorship of the ANM associate editors since 2016. This is our fourth serial review article written by the ANM specialty editors from their respective expert viewpoints.
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Affiliation(s)
- Masayuki Inubushi
- Division of Nuclear Medicine, Department of Radiology, Kawasaki Medical School, 577 Matsushima, Kurashiki, 701-0192, Okayama, Japan.
| | - Miho Shidahara
- Department of Quantum Science and Energy Engineering, Graduate School of Engineering, Tohoku University, Aobayama 6-6-01-2, Sendai, 980-8579, Miyagi, Japan
| | - Yasuyuki Takahashi
- Department of Radiation Science, Graduate School of Health Sciences, Hirosaki University, 66-1 Hon-cho, Hirosaki, 036-8564, Aomori, Japan
| | - Mikako Ogawa
- Laboratory for Bioanalysis and Molecular Imaging, Graduate School of Pharmaceutical Sciences, Hokkaido University, N12 W6, Kita-ku, Sapporo, 060-0812, Hokkaido, Japan
| | - Yasushi Kiyono
- Biomedical Imaging Research Center, University of Fukui, 23-3 Matsuoka-Shimoaizuki, Eiheiji-cho, Fukui, 910-1193, Japan
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Ruigrok EAM, van Weerden WM, Nonnekens J, de Jong M. The Future of PSMA-Targeted Radionuclide Therapy: An Overview of Recent Preclinical Research. Pharmaceutics 2019; 11:E560. [PMID: 31671763 PMCID: PMC6921028 DOI: 10.3390/pharmaceutics11110560] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 10/23/2019] [Accepted: 10/24/2019] [Indexed: 12/15/2022] Open
Abstract
Prostate specific membrane antigen (PSMA) has become a major focus point in the research and development of prostate cancer (PCa) imaging and therapeutic strategies using radiolabeled tracers. PSMA has shown to be an excellent target for PCa theranostics because of its high expression on the membrane of PCa cells and the increase in expression during disease progression. Therefore, numerous PSMA-targeting tracers have been developed and (pre)clinically studied with promising results. However, many of these PSMA-targeting tracers show uptake in healthy organs such as the salivary glands, causing radiotoxicity. Furthermore, not all patients respond to PSMA-targeted radionuclide therapy (TRT). This created the necessity of additional preclinical research studies in which existing tracers are reevaluated and new tracers are developed in order to improve PSMA-TRT by protecting the (PSMA-expressing) healthy organs and improving tumor uptake. In this review we will give an overview of the recent preclinical research projects regarding PCa-TRT using PSMA-specific radiotracers, which will give an indication of where the PSMA-TRT research movement is going and what we can expect in future clinical trials.
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Affiliation(s)
- Eline A M Ruigrok
- Dept. of Radiology and Nuclear Medicine, Erasmus MC, 3015 GD Rotterdam, The Netherlands.
- Dept. of Experimental Urology, Erasmus MC, 3015 GD Rotterdam, The Netherlands.
| | | | - Julie Nonnekens
- Dept. of Radiology and Nuclear Medicine, Erasmus MC, 3015 GD Rotterdam, The Netherlands.
- Dept. of Molecular Genetics, Erasmus MC, 3015 GD Rotterdam, The Netherlands.
- Oncode Institute, Erasmus MC, 3015 GD Rotterdam, The Netherlands.
| | - Marion de Jong
- Dept. of Radiology and Nuclear Medicine, Erasmus MC, 3015 GD Rotterdam, The Netherlands.
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Banerjee SR, Kumar V, Lisok A, Chen J, Minn I, Brummet M, Boinapally S, Cole M, Ngen E, Wharram B, Brayton C, Hobbs RF, Pomper MG. 177Lu-labeled low-molecular-weight agents for PSMA-targeted radiopharmaceutical therapy. Eur J Nucl Med Mol Imaging 2019; 46:2545-2557. [PMID: 31399803 DOI: 10.1007/s00259-019-04434-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 07/09/2019] [Indexed: 11/29/2022]
Abstract
PURPOSE To develop a prostate-specific membrane antigen (PSMA)-targeted radiotherapeutic for metastatic castration-resistant prostate cancer (mCRPC) with optimized efficacy and minimized toxicity employing the β-particle radiation of 177Lu. METHODS We synthesized 14 new PSMA-targeted, 177Lu-labeled radioligands (177Lu-L1-177Lu-L14) using different chelating agents and linkers. We evaluated them in vitro using human prostate cancer PSMA(+) PC3 PIP and PSMA(-) PC3 flu cells and in corresponding flank tumor models. Efficacy and toxicity after 8 weeks were evaluated at a single administration of 111 MBq for 177Lu-L1, 177Lu-L3, 177Lu-L5 and 177Lu-PSMA-617. Efficacy of 177Lu-L1 was further investigated using different doses, and long-term toxicity was determined in healthy immunocompetent mice. RESULTS Radioligands were produced in high radiochemical yield and purity. Cell uptake and internalization indicated specific uptake only in PSMA(+) PC3 cells. 177Lu-L1, 177Lu-L3 and 177Lu-L5 demonstrated comparable uptake to 177Lu-PSMA-617 and 177Lu-PSMA-I&T in PSMA-expressing tumors up to 72 h post-injection. 177Lu-L1, 177Lu-L3 and 177Lu-L5 also demonstrated efficient tumor regression at 8 weeks. 177Lu-L1 enabled the highest survival rate. Necropsy studies of the treated group at 8 weeks revealed subacute damage to lacrimal glands and testes. No radiation nephropathy was observed 1 year post-treatment in healthy mice receiving 111 MBq of 177Lu-L1, most likely related to the fast renal clearance of this agent. CONCLUSIONS 177Lu-L1 is a viable clinical candidate for radionuclide therapy of PSMA-expressing malignancies because of its high tumor-targeting ability and low off-target radiotoxic effects.
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Affiliation(s)
- Sangeeta Ray Banerjee
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA. .,Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - Vivek Kumar
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Ala Lisok
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jian Chen
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Il Minn
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Mary Brummet
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Srikanth Boinapally
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Michael Cole
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Ethel Ngen
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Bryan Wharram
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Cory Brayton
- Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Robert F Hobbs
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Martin G Pomper
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA. .,Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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Zorzi A, Linciano S, Angelini A. Non-covalent albumin-binding ligands for extending the circulating half-life of small biotherapeutics. MEDCHEMCOMM 2019; 10:1068-1081. [PMID: 31391879 PMCID: PMC6644573 DOI: 10.1039/c9md00018f] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 06/01/2019] [Indexed: 12/13/2022]
Abstract
Peptides and small protein scaffolds are gaining increasing interest as therapeutics. Similarly to full-length antibodies, they can bind a target with a high binding affinity and specificity while remaining small enough to diffuse into tissues. However, despite their numerous advantages, small biotherapeutics often suffer from a relatively short circulating half-life, thus requiring frequent applications that ultimately restrict their ease of use and user compliance. To overcome this limitation, a large variety of half-life extension strategies have been developed in the last decades. Linkage to ligands that non-covalently bind to albumin, the most abundant serum protein with a circulating half-life of ∼19 days in humans, represents one of the most successful approaches for the generation of long-lasting biotherapeutics with improved pharmacokinetic properties and superior efficacy in the clinic.
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Affiliation(s)
- Alessandro Zorzi
- Institute of Chemical Sciences and Engineering , School of Basic Sciences , Ecole Polytechnique Fédérale de Lausanne (EPFL) , Lausanne CH-1015 , Switzerland
| | - Sara Linciano
- Department of Molecular Sciences and Nanosystems , Ca' Foscari University of Venice , Via Torino 155 , Venezia Mestre 30172 , Italy
| | - Alessandro Angelini
- Department of Molecular Sciences and Nanosystems , Ca' Foscari University of Venice , Via Torino 155 , Venezia Mestre 30172 , Italy
- European Centre for Living Technologies (ECLT) , San Marco 2940 , Venice 30124 , Italy .
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Pal A, Albusairi W, Liu F, Tuhin MTH, Miller M, Liang D, Joo H, Amin TU, Wilson EA, Faridi JS, Park M, Alhamadsheh MM. Hydrophilic Small Molecules That Harness Transthyretin To Enhance the Safety and Efficacy of Targeted Chemotherapeutic Agents. Mol Pharm 2019; 16:3237-3252. [PMID: 31136717 PMCID: PMC6607395 DOI: 10.1021/acs.molpharmaceut.9b00432] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
![]()
The
hydrophobicity of many chemotherapeutic agents usually results
in their nonselective passive distribution into healthy cells and
organs causing collateral toxicity. Ligand-targeted drugs (LTDs) are
a promising class of targeted anticancer agents. The hydrophilicity
of the targeting ligands in LTDs limits its nonselective passive tissue
distribution and toxicity to healthy cells. In addition, the small
size of LTDs allows for better tumor penetration, especially in the
case of solid tumors. However, the short circulation half-life of
LTDs, due to their hydrophilicity and small size, remains a significant
challenge for achieving their full therapeutic potential. Therefore,
extending the circulation half-life of targeted chemotherapeutic agents
while maintaining their hydrophilicity and small size will represent
a significant advance toward effective and safe cancer treatment.
Here, we present a new approach for enhancing the safety and efficacy
of targeted chemotherapeutic agents. By endowing hydrophobic chemotherapeutic
agents with a targeting moiety and a hydrophilic small molecule that
binds reversibly to the serum protein transthyretin, we generated
small hydrophilic drug conjugates that displayed enhanced circulation
half-life in rodents and selectivity to cancer cells. To the best
of our knowledge, this is the first demonstration of a successful
approach that maintains the small size and hydrophilicity of targeted
anticancer agents containing hydrophobic payloads while at the same
time extending their circulation half-life. This was demonstrated
by the superior in vivo efficacy and lower toxicity of our conjugates
in xenograft mouse models of metastatic prostate cancer.
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Abstract
As described in more detail in other contributions in this issue of Seminars in Nuclear Medicine, prostate-specific membrane antigen (PSMA) has become one of the most promising molecular targets in nuclear medicine. Due to its overexpression on prostate cancer cells in proportion to the stage and grade of tumour progression, especially in androgen-independent, advanced and metastatic disease, various tracers for the detection and treatment of prostate cancer by means of radioligand imaging, radioligand therapy or radioguided surgery have been developed and transferred to clinical applications. Even though monoclonal antibodies were investigated and introduced as first PSMA-targeted probes, the inherent advantage of fast tumour uptake and rapid excretion of small molecules has shifted the research focus during the last decade to low molecular weight inhibitors with high affinity to PSMA, such as [18F]FDCFPyL, [18F]PSMA-1007, [68Ga]PSMA-HBED, [177Lu]PSMA-617, [177Lu]PSMA-I&T, [99mTc]MIP-1404 or [99mTc]PSMA I&S, to mention only a few. Due to the plethora of such PSMA probes described during the last years, this review aims to give an overview over the specific characteristics of those radiopharmaceuticals that have already found widespread clinical application. In addition, recently introduced concepts such as PSMA-tracers with increased plasma protein binding, are discussed.
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Affiliation(s)
- Hans-Jürgen Wester
- Chair of Pharmaceutical Radiochemistry, Walther-Meissner-Strasse 3, 85748 Garching, Germany.
| | - Margret Schottelius
- Chair of Pharmaceutical Radiochemistry, Walther-Meissner-Strasse 3, 85748 Garching, Germany
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43
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Abstract
The current mainstay of treatment in metastatic prostate cancer is based on hormonal manipulations. Standard androgen deprivation therapy and novel androgen axis drugs are commonly well tolerable and can stabilize metastatic hormone-sensitive prostate cancers for years. However, metastatic castration-resistant prostate cancer is still challenging to treat. Except taxanes, prostate cancer presents intrinsic resistance against conventional chemotherapies. The typically elderly patient population excludes more aggressive treatment regimens. First clinical trials evaluating immunotherapy or tyrosine-kinase-inhibitors against prostate cancer failed. In contrast, prostate cancer can be radiosensitive and external beam radiotherapy is effective in localized prostate cancer, thus providing a good rationale for the use of systemic radiopharmaceuticals in the metastatic setting. Beta-particle emitting "bone-seekers" have a long history and are effective as analgesics but do not improve survival because they are limited by red-marrow dose. Alpha emitting 223Radium can be used in a dose that prolongs survival but is restricted to bone-confined patients. Currently radiolabeled high-affinity ligands to the prostate-specific membrane antigen are in clinical evaluation. While radioimmunotherapy approaches were limited by the long circulation time and slow tumor-accumulation of antibodies, low molecular weight PSMA-specific ligands offer an approx. ten-fold improved tumor to red-marrow ratio in comparison to the unspecific bone-seekers. Early clinical studies demonstrate that regarding surrogate markers, such as >50% PSA reduction (60%) and radiologic response (80%), PSMA-therapy exceeds the antitumor activity of all approved or other recently tested compounds; for example, PSA-response was only observed in approx. a total of 10% of patients treated with ipilimumab, sunitinib, cabozantinib, or xofigo, respectively and in approx. 30, 40, 50% of patients treated with abiraterone, cabazitaxel, or enzalutamide. Also progression free and overall survivals of these single-arm studies appear promising when compared to historical controls. Consecutively, the first PSMA-RLT recently advanced into phase-3 (177Lu-PSMA-617; VISION-trial). Future developments aim to avoid off-target radiation by ligand-optimization and to outperform the antitumor activity of beta-emitter PSMA-RLT by labeling with highly focused, high energy transferring alpha-nuclides; however the latter potentially also increasing the risk of side-effects and additional early phase studies are needed to improve treatment protocols. Academically clinical research is developing prognostic tools to improve treatment benefit by selecting the most appropriate patients in advance.
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Affiliation(s)
- Clemens Kratochwil
- Department of Nuclear Medicine, University Hospital Heidelberg, Heidelberg, Germany.
| | - Uwe Haberkorn
- Department of Nuclear Medicine, University Hospital Heidelberg, Heidelberg, Germany; Cooperation Unit Nuclear Medicine, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Frederik L Giesel
- Department of Nuclear Medicine, University Hospital Heidelberg, Heidelberg, Germany
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Brandt M, Cardinale J, Giammei C, Guarrochena X, Happl B, Jouini N, Mindt TL. Mini-review: Targeted radiopharmaceuticals incorporating reversible, low molecular weight albumin binders. Nucl Med Biol 2019; 70:46-52. [PMID: 30831342 DOI: 10.1016/j.nucmedbio.2019.01.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 01/18/2019] [Accepted: 01/21/2019] [Indexed: 12/20/2022]
Abstract
The combination of low molecular weight, reversible human serum albumin (HSA) binders with targeted radiopharmaceuticals in dual-targeted radioconjugates holds great promise, in particular for endoradiotherapy. Attachment of HSA-binders to radiopharmaceuticals extends their blood circulation time and results in an enhanced tumour uptake as well as often in an improved pharmacokinetic profile. In this mini-review, an overview of currently pursued approaches of this novel strategy is provided.
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Affiliation(s)
- Marie Brandt
- Ludwig Boltzmann Institute Applied Diagnostics, General Hospital of Vienna, Vienna, Austria; Department of Biomedical Imaging and Image Guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - Jens Cardinale
- Ludwig Boltzmann Institute Applied Diagnostics, General Hospital of Vienna, Vienna, Austria; Department of Biomedical Imaging and Image Guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - Carolina Giammei
- Ludwig Boltzmann Institute Applied Diagnostics, General Hospital of Vienna, Vienna, Austria; Department of Inorganic Chemistry, Faculty of Chemistry, University of Vienna, Vienna, Austria; Department of Biomedical Imaging and Image Guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - Xabier Guarrochena
- Ludwig Boltzmann Institute Applied Diagnostics, General Hospital of Vienna, Vienna, Austria; Department of Inorganic Chemistry, Faculty of Chemistry, University of Vienna, Vienna, Austria; Department of Biomedical Imaging and Image Guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - Barbara Happl
- Ludwig Boltzmann Institute Applied Diagnostics, General Hospital of Vienna, Vienna, Austria; Department of Inorganic Chemistry, Faculty of Chemistry, University of Vienna, Vienna, Austria; Department of Biomedical Imaging and Image Guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - Nedra Jouini
- Ludwig Boltzmann Institute Applied Diagnostics, General Hospital of Vienna, Vienna, Austria; Department of Inorganic Chemistry, Faculty of Chemistry, University of Vienna, Vienna, Austria; Department of Biomedical Imaging and Image Guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - Thomas L Mindt
- Ludwig Boltzmann Institute Applied Diagnostics, General Hospital of Vienna, Vienna, Austria; Department of Inorganic Chemistry, Faculty of Chemistry, University of Vienna, Vienna, Austria; Department of Biomedical Imaging and Image Guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria.
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Lau J, Jacobson O, Niu G, Lin KS, Bénard F, Chen X. Bench to Bedside: Albumin Binders for Improved Cancer Radioligand Therapies. Bioconjug Chem 2019; 30:487-502. [PMID: 30616340 DOI: 10.1021/acs.bioconjchem.8b00919] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Radioligand therapy (RLT) relies on the use of pharmacophores to selectively deliver ionization energy to cancers to exert its tumoricidal effects. Cancer cells that are not directly targeted by a radioconjugate remain susceptible to RLT because of the crossfire effect. This is significant given the inter- and intra-heterogeneity of tumors. In recent years, reversible albumin binders have been used as simple "add-ons" for radiopharmaceuticals to modify pharmacokinetics and to enhance therapeutic efficacy. In this Review, we discuss recent advances in albumin binder platforms used in RLT, with an emphasis on 4-( p-iodophenyl)butyric acid and Evans blue derivatives. We focus on four biological systems pertinent to oncology that utilize this class of compounds: folate receptor, integrin αvβ3, somatostatin receptor, and prostate-specific membrane antigen. Finally, we offer our perspectives on albumin binders for RLT, highlighting future areas of research that will help propel the technology further for clinical use.
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Affiliation(s)
- Joseph Lau
- Laboratory of Molecular Imaging and Nanomedicine (LOMIN), National Institute of Biomedical Imaging and Bioengineering (NIBIB) , National Institutes of Health (NIH) , Bethesda , Maryland 20892 , United States
| | - Orit Jacobson
- Laboratory of Molecular Imaging and Nanomedicine (LOMIN), National Institute of Biomedical Imaging and Bioengineering (NIBIB) , National Institutes of Health (NIH) , Bethesda , Maryland 20892 , United States
| | - Gang Niu
- Laboratory of Molecular Imaging and Nanomedicine (LOMIN), National Institute of Biomedical Imaging and Bioengineering (NIBIB) , National Institutes of Health (NIH) , Bethesda , Maryland 20892 , United States
| | - Kuo-Shyan Lin
- Department of Molecular Oncology , BC Cancer , Vancouver , British Columbia V5Z 1L3 , Canada
| | - François Bénard
- Department of Molecular Oncology , BC Cancer , Vancouver , British Columbia V5Z 1L3 , Canada
| | - Xiaoyuan Chen
- Laboratory of Molecular Imaging and Nanomedicine (LOMIN), National Institute of Biomedical Imaging and Bioengineering (NIBIB) , National Institutes of Health (NIH) , Bethesda , Maryland 20892 , United States
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Kelly JM, Amor-Coarasa A, Ponnala S, Nikolopoulou A, Williams C, DiMagno SG, Babich JW. Albumin-Binding PSMA Ligands: Implications for Expanding the Therapeutic Window. J Nucl Med 2018; 60:656-663. [PMID: 30552199 DOI: 10.2967/jnumed.118.221150] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 11/30/2018] [Indexed: 11/16/2022] Open
Abstract
Despite significant gains in the treatment of metastatic castration-resistant prostate cancer by radioligands targeting prostate-specific membrane antigen (PSMA), 30% of patients never respond to therapy. One possible explanation is insufficient dose delivery to the tumor because of suboptimal pharmacokinetics. We have recently described RPS-063, a trifunctional ligand targeting PSMA with high uptake in LNCaP xenograft tumors but also in kidneys. We aimed to use structural modifications to increase the tumor-to-kidney ratio through increased albumin binding and tumor uptake and reduction of kidney activity. Methods: Four structurally related trifunctional PSMA-targeting small molecules were prepared by either varying the albumin-binding group or inserting a polyethylene glycol 8 linker into a common structure. The compounds were ranked by PSMA affinity and albumin affinity and were radiolabeled with 68Ga and 177Lu. Tissue kinetics were determined in male BALB/C nu/nu mice bearing LNCaP xenograft tumors. Results: Each of the compounds binds PSMA with a half-maximal inhibitory concentration of no more than 10 nM. The albumin-binding group had a minimal effect on PSMA affinity but changed albumin affinity by an order of magnitude. However, the addition of a polyethylene glycol 8 spacer weakened affinity for albumin in each case. Increased affinity for albumin corresponded with delayed blood clearance and modified uptake kinetics in the tumor and kidney. Uptake of 177Lu-RPS-072 (34.9 ± 2.4 %ID/g) and 177Lu-RPS-077 (27.4 ± 0.6 %ID/g) increased up to 24 h after injection, and washout by 96 h was not significant. As a result, the area under the curve (AUC) in the tumor was in the following order: 177Lu-RPS-072 > 177Lu-RPS-077 > 177Lu-RPS-063 > 177Lu-RPS-071. Increased linker length corresponded to more rapid clearance from kidneys. Consequently, the ratio of tumor AUC and kidney AUC was 4.7 ± 0.3 for 177Lu-RPS-072. Conclusion: The tumor AUC and tumor-to-kidney ratio of 177Lu-RPS-072 are significantly enhanced compared with any small molecule investigated in a LNCaP xenograft model to date. In comparison to other PSMA-targeting radioligands that have been evaluated in a PC3-PIP model, activity in kidneys is reduced and activity in tumors compares favorably when the different PSMA expression levels in LNCaP and PC3-PIP cells are considered. RPS-072 therefore exhibits an increased therapeutic index, shows the potential to increase the dose delivered to tumors, and is a highly promising candidate for targeted radioligand therapy.
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Affiliation(s)
- James M Kelly
- Molecular Imaging Innovations Institute (MI3), Department of Radiology, Weill Cornell Medicine, New York, New York.,Division of Radiopharmaceutical Science, Department of Radiology, Weill Cornell Medicine, New York, New York
| | - Alejandro Amor-Coarasa
- Molecular Imaging Innovations Institute (MI3), Department of Radiology, Weill Cornell Medicine, New York, New York.,Division of Radiopharmaceutical Science, Department of Radiology, Weill Cornell Medicine, New York, New York
| | - Shashikanth Ponnala
- Molecular Imaging Innovations Institute (MI3), Department of Radiology, Weill Cornell Medicine, New York, New York.,Division of Radiopharmaceutical Science, Department of Radiology, Weill Cornell Medicine, New York, New York
| | - Anastasia Nikolopoulou
- Division of Radiopharmaceutical Science, Department of Radiology, Weill Cornell Medicine, New York, New York.,Citigroup Biomedical Imaging Center, Weill Cornell Medicine, New York, New York
| | - Clarence Williams
- Molecular Imaging Innovations Institute (MI3), Department of Radiology, Weill Cornell Medicine, New York, New York.,Division of Radiopharmaceutical Science, Department of Radiology, Weill Cornell Medicine, New York, New York
| | - Stephen G DiMagno
- College of Pharmacy, University of Illinois-Chicago, Chicago, Illinois; and
| | - John W Babich
- Molecular Imaging Innovations Institute (MI3), Department of Radiology, Weill Cornell Medicine, New York, New York .,Division of Radiopharmaceutical Science, Department of Radiology, Weill Cornell Medicine, New York, New York.,Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, New York, New York
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Kelly JM, Amor-Coarasa A, Ponnala S, Nikolopoulou A, Williams C, Thiele NA, Schlyer D, Wilson JJ, DiMagno SG, Babich JW. A Single Dose of 225Ac-RPS-074 Induces a Complete Tumor Response in an LNCaP Xenograft Model. J Nucl Med 2018; 60:649-655. [PMID: 30413660 DOI: 10.2967/jnumed.118.219592] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 10/03/2018] [Indexed: 12/13/2022] Open
Abstract
Promising biochemical responses to 225Ac-prostate-specific membrane antigen (PSMA) 617, even in patients who are refractory to β-particle radiation, illustrate the potential of targeted α-therapy for the treatment of metastatic castration-resistant prostate cancer. However, side effects such as xerostomia are severe and irreversible. To fully harness the potential of targeted α-therapy, it is necessary to increase the therapeutic index of the targeted radioligands. One emerging strategy is to increase clearance half-life through enhanced binding to serum albumin. We have evaluated the albumin-binding PSMA-targeting ligand RPS-074 in a LNCaP xenograft model to determine its potential value to the treatment of prostate cancer. Methods: 225Ac-RPS-074 was evaluated in male BALB/c mice bearing LNCaP xenograft tumors. A biodistribution study was performed over 21 d to determine the dosimetry in tumors and normal tissue. The dose response was measured in groups of 7 mice using 37, 74, and 148 kBq of 225Ac-RPS-074 and compared with positive and negative control groups. Mice were sacrificed when tumor volume exceeded 1,500 mm3 Results: 225Ac-RPS-074 was labeled in greater than 98% radiochemical yield and showed high (>10% injected dose/g) and sustained accumulation in LNCaP tumors from 24 h to beyond 14 d. Signal in blood and highly vascularized tissues was evident over the first 24 h after injection and cleared by 7 d. The tumor-to-kidney ratio was 4.3 ± 0.7 at 24 h and 62.2 ± 9.5 at 14 d. A single injection of 148 kBq induced a complete response in 6 of 7 tumors, with no apparent toxic effects. Treatment with 74 kBq induced a partial response in 7 of 7 tumors, but from 42 d, 6 of 7 experienced significant regrowth. The 37-kBq group experienced a survival benefit relative to the negative control but not compared with the positive control group. Conclusion: A single dose of 148 kBq of 225Ac-RPS-074 induced a complete response in 86% of tumors, with tumor-to-normal-tissue ratios that predict an improved therapeutic index. The use of the macropa chelator enabled quantitative radiolabeling and may facilitate the clinical translation of this promising targeted α-therapeutic.
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Affiliation(s)
- James M Kelly
- Division of Radiopharmaceutical Science, Department of Radiology, Weill Cornell Medicine, New York, New York.,Molecular Imaging Innovations Institute (MI3), Department of Radiology, Weill Cornell Medicine, New York, New York
| | - Alejandro Amor-Coarasa
- Division of Radiopharmaceutical Science, Department of Radiology, Weill Cornell Medicine, New York, New York.,Molecular Imaging Innovations Institute (MI3), Department of Radiology, Weill Cornell Medicine, New York, New York
| | - Shashikanth Ponnala
- Division of Radiopharmaceutical Science, Department of Radiology, Weill Cornell Medicine, New York, New York.,Molecular Imaging Innovations Institute (MI3), Department of Radiology, Weill Cornell Medicine, New York, New York
| | - Anastasia Nikolopoulou
- Division of Radiopharmaceutical Science, Department of Radiology, Weill Cornell Medicine, New York, New York.,Citigroup Biomedical Imaging Center, Weill Cornell Medicine, New York, New York
| | - Clarence Williams
- Division of Radiopharmaceutical Science, Department of Radiology, Weill Cornell Medicine, New York, New York.,Molecular Imaging Innovations Institute (MI3), Department of Radiology, Weill Cornell Medicine, New York, New York
| | - Nikki A Thiele
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York
| | | | - Justin J Wilson
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York
| | - Stephen G DiMagno
- College of Pharmacy, University of Illinois-Chicago, Chicago, Illinois; and
| | - John W Babich
- Division of Radiopharmaceutical Science, Department of Radiology, Weill Cornell Medicine, New York, New York .,Molecular Imaging Innovations Institute (MI3), Department of Radiology, Weill Cornell Medicine, New York, New York.,Citigroup Biomedical Imaging Center, Weill Cornell Medicine, New York, New York.,Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, New York, New York
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Umbricht CA, Benešová M, Hasler R, Schibli R, van der Meulen NP, Müller C. Design and Preclinical Evaluation of an Albumin-Binding PSMA Ligand for 64Cu-Based PET Imaging. Mol Pharm 2018; 15:5556-5564. [DOI: 10.1021/acs.molpharmaceut.8b00712] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
| | - Martina Benešová
- Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland
| | | | - Roger Schibli
- Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland
| | | | - Cristina Müller
- Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland
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Amor-Coarasa A, Kelly JM, Ponnala S, Nikolopoulou A, Williams C, Babich JW. 66Ga: A Novelty or a Valuable Preclinical Screening Tool for the Design of Targeted Radiopharmaceuticals? Molecules 2018; 23:molecules23102575. [PMID: 30304795 PMCID: PMC6222850 DOI: 10.3390/molecules23102575] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 10/01/2018] [Accepted: 10/05/2018] [Indexed: 11/30/2022] Open
Abstract
Emerging interest in extending the plasma half-life of small molecule radioligands warrants a consideration of the appropriate radionuclide for PET imaging at longer time points (>8 h). Among candidate positron-emitting radionuclides, 66Ga (t1/2 = 9.5 h, β+ = 57%) has suitable nuclear and chemical properties for the labeling and PET imaging of radioligands of this profile. We investigated the value of 66Ga to preclinical screening and the evaluation of albumin-binding PSMA-targeting small molecules. 66Ga was produced by irradiation of a natZn target. 66Ga3+ ions were separated from Zn2+ ions by an optimized UTEVA anion exchange column that retained 99.99987% of Zn2+ ions and allowed 90.2 ± 2.8% recovery of 66Ga3+. Three ligands were radiolabeled in 46.4 ± 20.5%; radiochemical yield and >90% radiochemical purity. Molar activity was 632 ± 380 MBq/µmol. Uptake in the tumor and kidneys at 1, 3, 6, and 24 h p.i. was determined by µPET/CT imaging and more completely predicted the distribution kinetics than uptake of the [68Ga]Ga-labeled ligands did. Although there are multiple challenges to the use of 66Ga for clinical PET imaging, it can be a valuable research tool for ligand screening and preclinical imaging beyond 24 h.
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Affiliation(s)
- Alejandro Amor-Coarasa
- Division of Radiopharmaceutical Sciences and MI3, Department of Radiology, Weill Cornell Medicine, New York, NY 10065, USA.
| | - James M Kelly
- Division of Radiopharmaceutical Sciences and MI3, Department of Radiology, Weill Cornell Medicine, New York, NY 10065, USA.
| | - Shashikanth Ponnala
- Division of Radiopharmaceutical Sciences and MI3, Department of Radiology, Weill Cornell Medicine, New York, NY 10065, USA.
| | - Anastasia Nikolopoulou
- Division of Radiopharmaceutical Sciences and MI3, Department of Radiology, Weill Cornell Medicine, New York, NY 10065, USA.
- Citigroup Biomedical Imaging Center, Weill Cornell Medicine, New York, NY 10065, USA.
| | - Clarence Williams
- Division of Radiopharmaceutical Sciences and MI3, Department of Radiology, Weill Cornell Medicine, New York, NY 10065, USA.
| | - John W Babich
- Division of Radiopharmaceutical Sciences and MI3, Department of Radiology, Weill Cornell Medicine, New York, NY 10065, USA.
- Citigroup Biomedical Imaging Center, Weill Cornell Medicine, New York, NY 10065, USA.
- Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10065, USA.
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50
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Kuo HT, Merkens H, Zhang Z, Uribe CF, Lau J, Zhang C, Colpo N, Lin KS, Bénard F. Enhancing Treatment Efficacy of 177Lu-PSMA-617 with the Conjugation of an Albumin-Binding Motif: Preclinical Dosimetry and Endoradiotherapy Studies. Mol Pharm 2018; 15:5183-5191. [PMID: 30251544 DOI: 10.1021/acs.molpharmaceut.8b00720] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
We designed and evaluated a novel albumin-binder-conjugated 177Lu-PSMA-617 derivative, 177Lu-HTK01169, with an extended blood retention time to maximize the radiation dose delivered to prostate tumors expressing prostate-specific membrane antigen (PSMA). PSMA-617 and HTK01169 that contained N-[4-( p-iodophenyl)butanoyl]-Glu as an albumin-binding motif were synthesized using the solid-phase approach. Binding affinity to PSMA was determined by in vitro competition-binding assay. 177Lu labeling was performed in acetate buffer (pH 4.5) at 90 °C for 15 min. SPECT/CT imaging, biodistribution, and endoradiotherapy studies were conducted in mice bearing PSMA-expressing LNCaP tumor xenografts. Radiation dosimetry was calculated using OLINDA software. Lu-PSMA-617 and Lu-HTK01169-bound PSMA with high affinity ( Ki values = 0.24 and 0.04 nM, respectively). SPECT imaging and biodistribution studies showed that 177Lu-PSMA-617 and 177Lu-HTK01169 were excreted mainly via the renal pathway. With fast blood clearance (0.68%ID/g at 1 h postinjection), the tumor uptake of 177Lu-PSMA-617 peaked at 1 h postinjection (15.1%ID/g) and gradually decreased to 7.91%ID/g at 120 h postinjection. With extended blood retention (16.6 and 2.10%ID/g at 1 and 24 h, respectively), the tumor uptake of 177Lu-HTK01169 peaked at 24 h postinjection (55.9%ID/g) and remained at the same level by the end of the study (120 h). Based on dosimetry calculations, 177Lu-HTK01169 delivered an 8.3-fold higher radiation dose than 177Lu-PSMA-617 to LNCaP tumor xenografts. For the endoradiotherapy study, the mice treated with 177Lu-PSMA-617 (18.5 MBq) all reached humane end point (tumor volume >1000 mm3) by Day 73 with a median survival of 58 days. Mice treated with 18.5, 9.3, 4.6, or 2.3 MBq of 177Lu-HTK01169 had a median survival of >120, 103, 61, and 28 days, respectively. With greatly enhanced tumor uptake and treatment efficacy compared to 177Lu-PSMA-617 in preclinical studies, 177Lu-HTK01169 warrants further investigation for endoradiotherapy of prostate cancer.
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Affiliation(s)
- Hsiou-Ting Kuo
- Department of Molecular Oncology , BC Cancer , Vancouver , BC V5Z 1L3 , Canada
| | - Helen Merkens
- Department of Molecular Oncology , BC Cancer , Vancouver , BC V5Z 1L3 , Canada
| | - Zhengxing Zhang
- Department of Molecular Oncology , BC Cancer , Vancouver , BC V5Z 1L3 , Canada
| | - Carlos F Uribe
- Department of Molecular Oncology , BC Cancer , Vancouver , BC V5Z 1L3 , Canada
| | - Joseph Lau
- Department of Molecular Oncology , BC Cancer , Vancouver , BC V5Z 1L3 , Canada
| | - Chengcheng Zhang
- Department of Molecular Oncology , BC Cancer , Vancouver , BC V5Z 1L3 , Canada
| | - Nadine Colpo
- Department of Molecular Oncology , BC Cancer , Vancouver , BC V5Z 1L3 , Canada
| | - Kuo-Shyan Lin
- Department of Molecular Oncology , BC Cancer , Vancouver , BC V5Z 1L3 , Canada.,Department of Functional Imaging , BC Cancer , Vancouver , BC V5Z 4E6 , Canada.,Department of Radiology , University of British Columbia , Vancouver , BC V5Z 1M9 , Canada
| | - François Bénard
- Department of Molecular Oncology , BC Cancer , Vancouver , BC V5Z 1L3 , Canada.,Department of Functional Imaging , BC Cancer , Vancouver , BC V5Z 4E6 , Canada.,Department of Radiology , University of British Columbia , Vancouver , BC V5Z 1M9 , Canada
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