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Suzuki H, Kannaka K, Hirayama M, Yamashita T, Kaizuka Y, Kobayashi R, Yasuda T, Takahashi K, Uehara T. In vivo stable 211At-labeled prostate-specific membrane antigen-targeted tracer using a neopentyl glycol structure. EJNMMI Radiopharm Chem 2024; 9:48. [PMID: 38884866 PMCID: PMC11183015 DOI: 10.1186/s41181-024-00278-8] [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: 03/25/2024] [Accepted: 05/31/2024] [Indexed: 06/18/2024] Open
Abstract
BACKGROUND Prostate cancer is a common cancer among men worldwide that has a very poor prognosis, especially when it progresses to metastatic castration-resistant prostate cancer (mCRPC). Therefore, novel therapeutic agents for mCRPC are urgently required. Because prostate-specific membrane antigen (PSMA) is overexpressed in mCRPC, targeted alpha therapy (TAT) for PSMA is a promising treatment for mCRPC. Astatine-211 (211At) is a versatile α-emitting radionuclide that can be produced using a cyclotron. Therefore, 211At-labeled PSMA compounds could be useful for TAT; however, 211At-labeled compounds are unstable against deastatination in vivo. In this study, to develop in vivo stable 211At-labeled PSMA derivatives, we designed and synthesized 211At-labeled PSMA derivatives using a neopentyl glycol (NpG) structure that can stably retain 211At in vivo. We also evaluated their biodistribution in normal and tumor-bearing mice. RESULTS We designed and synthesized 211At-labeled PSMA derivatives containing two glutamic acid (Glu) linkers between the NpG structure and asymmetric urea (NpG-L-PSMA ((L-Glu)2 linker used) and NpG-D-PSMA ((D-Glu)2 linker used)). First, we evaluated the characteristics of 125I-labeled NpG derivatives because 125I was readily available. [125I]I-NpG-L-PSMA and [125I]I-NpG-D-PSMA showed low accumulation in the stomach and thyroid, indicating their high in vivo stability against deiodination. [125I]I-NpG-L-PSMA was excreted in urine as hydrophilic radiometabolites in addition to the intact form. Meanwhile, [125I]I-NpG-D-PSMA was excreted in urine in an intact form. In both cases, no radioactivity was observed in the free iodine fraction. [125I]I-NpG-D-PSMA showed higher tumor accumulation than [125I]I-NpG-L-PSMA. We then developed 211At-labeled PSMA using the NpG-D-PSMA structure. [211At]At-NpG-D-PSMA showed low accumulation in the stomach and thyroid in normal mice, indicating its high stability against deastatination in vivo. Moreover, [211At]At-NpG-D-PSMA showed high accumulation in tumor similar to that of [125I]I-NpG-D-PSMA. CONCLUSIONS [211At]At-NpG-D-PSMA showed high in vivo stability against deastatination and high tumor accumulation. [211At]At-NpG-D-PSMA should be considered as a potential new TAT for mCRPC.
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Affiliation(s)
- Hiroyuki Suzuki
- Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Chuo-Ku, Inohana, Chiba, 260-8675, Japan
| | - Kento Kannaka
- Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Chuo-Ku, Inohana, Chiba, 260-8675, Japan
| | - Mizuki Hirayama
- Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Chuo-Ku, Inohana, Chiba, 260-8675, Japan
| | - Tomoki Yamashita
- Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Chuo-Ku, Inohana, Chiba, 260-8675, Japan
| | - Yuta Kaizuka
- Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Chuo-Ku, Inohana, Chiba, 260-8675, Japan
| | - Ryota Kobayashi
- Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Chuo-Ku, Inohana, Chiba, 260-8675, Japan
| | - Takahiro Yasuda
- Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Chuo-Ku, Inohana, Chiba, 260-8675, Japan
| | - Kazuhiro Takahashi
- Advanced Clinical Research Center, Fukushima Medical University, 1 Hikariga-Oka, Fukushima, 960-12195, Japan
| | - Tomoya Uehara
- Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Chuo-Ku, Inohana, Chiba, 260-8675, Japan.
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Patel KS, Singh T, Raghuvanshi K, Sonar S, Chaudhari R. A comparison study of 68gallium-prostate-specific membrane antigen positron emission tomography-computed tomography and multiparametric magnetic resonance imaging for locoregional staging of prostate cancer. UROLOGICAL SCIENCE 2024; 35:36-41. [PMID: 38566885 PMCID: PMC10984629 DOI: 10.1097/us9.0000000000000002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Indexed: 04/04/2024] Open
Abstract
Purpose Prostate cancer (PCa) is the most common malignancy in men aged 50 years and older and the second cause of cancer death among men. Accurate staging of PCa preoperatively is of high importance for treatment decisions and patient management. Conventional imaging modalities (ultrasound, computed tomography [CT], and magnetic resonance imaging) are inaccurate for the staging of PCa. Newer modality multiparametric magnetic resonance imaging (mpMRI) and prostate-specific membrane antigen (PSMA) positron emission tomography (PET) scan show promising results for the staging of PCa. Only fewer studies are available for comparison of these modalities with histopathology as reference. The objective of our study is to evaluate the diagnostic accuracy of independent 68gallium PSMA (68Ga-PSMA) PET-CT compared with mpMRI for preoperative staging of PCa, using histopathology as the reference standard. Materials and methods From August 2021 to December 2022, 30 patients of biopsy-proven PCa were prospectively enrolled as per eligibility criteria. Preoperatively, 68Ga-PSMA PET scan and mpMRI were done in all the patients. Extracapsular extension (ECE), seminal vesicle invasion (SVI), and lymph node metastasis (LNM) were investigated separately. Subsequently, the patients underwent robotic-assisted radical prostatectomy with bilateral pelvic lymph node dissection. Results mpMRI prostate was more sensitive (66.66%) but less specific than PSMA PET-CT (55.55%) for ECE. mpMRI and PSMA PET-CT both had similar sensitivity (83.3%) and specificity (87.5%) for SVI. PSMA PET-CT was more sensitive (85.71%) and specific (95.6%) than mpMRI prostate (62.5% and 91.30%, respectively) for LNM. Conclusion PSMA PET-CT is more specific for the detection of ECE and more sensitive and specific for the detection of LNM than mpMRI, and similar for the detection of SVI. mpMRI provides only local staging, while PSMA PET-CT provides information about local, regional, and distal staging. Overall, PSMA PET-CT is superior to mpMRI for locoregional staging of PCa.
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Affiliation(s)
| | - Tarun Singh
- Department of Nuclear Medicine, Ruby Hall Clinic
| | | | - Sameer Sonar
- Department of Nuclear Medicine, Ruby Hall Clinic
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Van Laere C, Koole M, Deroose CM, de Voorde MV, Baete K, Cocolios TE, Duchemin C, Ooms M, Cleeren F. Terbium radionuclides for theranostic applications in nuclear medicine: from atom to bedside. Theranostics 2024; 14:1720-1743. [PMID: 38389843 PMCID: PMC10879862 DOI: 10.7150/thno.92775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 02/07/2024] [Indexed: 02/24/2024] Open
Abstract
Terbium features four clinically interesting radionuclides for application in nuclear medicine: terbium-149, terbium-152, terbium-155, and terbium-161. Their identical chemical properties enable the synthesis of radiopharmaceuticals with the same pharmacokinetic character, while their distinctive decay characteristics make them valuable for both imaging and therapeutic applications. In particular, terbium-152 and terbium-155 are useful candidates for positron emission tomography (PET) and single photon emission computed tomography (SPECT) imaging, respectively; whereas terbium-149 and terbium-161 find application in α- and β--/Auger electron therapy, respectively. This unique characteristic makes the terbium family ideal for the "matched-pair" principle of theranostics. In this review, the advantages and challenges of terbium-based radiopharmaceuticals are discussed, covering the entire chain from radionuclide production to bedside administration. It elaborates on the fundamental properties of terbium, the production routes of the four interesting radionuclides and gives an overview of the available bifunctional chelators. Finally, we discuss the preclinical and clinical studies as well as the prospects of this promising development in nuclear medicine.
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Affiliation(s)
- Camille Van Laere
- Belgian Nuclear Research Centre (SCK CEN), Institute for Nuclear Medical Applications, Mol, Belgium
- Radiopharmaceutical Research, Department of Pharmacy and Pharmacology, KU Leuven, Leuven, Belgium
| | - Michel Koole
- Nuclear Medicine, University Hospitals Leuven, Belgium
- Nuclear Medicine & Molecular Imaging, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - Christophe M. Deroose
- Nuclear Medicine, University Hospitals Leuven, Belgium
- Nuclear Medicine & Molecular Imaging, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - Michiel Van de Voorde
- Belgian Nuclear Research Centre (SCK CEN), Institute for Nuclear Medical Applications, Mol, Belgium
| | - Kristof Baete
- Nuclear Medicine, University Hospitals Leuven, Belgium
- Nuclear Medicine & Molecular Imaging, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - Thomas E. Cocolios
- KU Leuven, Institute for Nuclear and Radiation Physics, Department of Physics and Astronomy, Leuven, Belgium
| | | | - Maarten Ooms
- Belgian Nuclear Research Centre (SCK CEN), Institute for Nuclear Medical Applications, Mol, Belgium
| | - Frederik Cleeren
- Radiopharmaceutical Research, Department of Pharmacy and Pharmacology, KU Leuven, Leuven, Belgium
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Santos JF, Braz MT, Raposinho P, Cleeren F, Cassells I, Leekens S, Cawthorne C, Mendes F, Fernandes C, Paulo A. Synthesis and Preclinical Evaluation of PSMA-Targeted 111In-Radioconjugates Containing a Mitochondria-Tropic Triphenylphosphonium Carrier. Mol Pharm 2024; 21:216-233. [PMID: 37992229 DOI: 10.1021/acs.molpharmaceut.3c00787] [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] [Indexed: 11/24/2023]
Abstract
Nuclear DNA is the canonical target for biological damage induced by Auger electrons (AE) in the context of targeted radionuclide therapy (TRT) of cancer, but other subcellular components might also be relevant for this purpose, such as the energized mitochondria of tumor cells. Having this in mind, we have synthesized novel DOTA-based chelators carrying a prostate-specific membrane antigen (PSMA) inhibitor and a triphenyl phosphonium (TPP) group that were used to obtain dual-targeted 111In-radioconjugates ([111In]In-TPP-DOTAGA-PSMA and [111In]In-TPP-DOTAGA-G3-PSMA), aiming to promote a selective uptake of an AE-emitter radiometal (111In) by PSMA+ prostate cancer (PCa) cells and an enhanced accumulation in the mitochondria. These dual-targeted 111In-radiocomplexes are highly stable under physiological conditions and in cell culture media. The complexes showed relatively similar binding affinities toward the PSMA compared to the reference tracer [111In]In-PSMA-617, in line with their high cellular uptake and internalization in PSMA+ PCa cells. The complexes compromised cell survival in a dose-dependent manner and in the case of [111In]In-TPP-DOTAGA-G3-PSMA to a higher extent than observed for the single-targeted congener [111In]In-PSMA-617. μSPECT imaging studies in PSMA+ PCa xenografts showed that the TPP pharmacophore did not interfere with the excellent in vivo tumor uptake of the "golden standard" [111In]In-PSMA-617, although it led to a higher kidney retention. Such kidney retention does not necessarily compromise their usefulness as radiotherapeutics due to the short tissue range of the Auger/conversion electrons emitted by 111In. Overall, our results provide valuable insights into the potential use of mitochondrial targeting by PSMA-based radiocomplexes for efficient use of AE-emitting radionuclides in TRT, giving impetus to extend the studies to other AE-emitting trivalent radiometals (e.g., 161Tb or 165Er) and to further optimize the designed dual-targeting constructs.
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Affiliation(s)
- Joana F Santos
- C2TN - Centro de Ciências e Tecnologias Nucleares Instituto Superior Técnico, Universidade de Lisboa, 2695-066 Bobadela LRS, Portugal
| | - Maria T Braz
- C2TN - Centro de Ciências e Tecnologias Nucleares Instituto Superior Técnico, Universidade de Lisboa, 2695-066 Bobadela LRS, Portugal
| | - Paula Raposinho
- C2TN - Centro de Ciências e Tecnologias Nucleares Instituto Superior Técnico, Universidade de Lisboa, 2695-066 Bobadela LRS, Portugal
- DECN - Departamento de Engenharia e Ciências Nucleares, Instituto Superior Técnico, Universidade de Lisboa, 2695-066 Bobadela LRS, Portugal
| | - Frederik Cleeren
- Laboratory for Radiopharmaceutical Research, Department of Pharmacy and Pharmacology, University of Leuven, B-3000 Leuven, Belgium
| | - Irwin Cassells
- Laboratory for Radiopharmaceutical Research, Department of Pharmacy and Pharmacology, University of Leuven, B-3000 Leuven, Belgium
- Nuclear Medical Applications, Belgian Nuclear Research Centre (SCK CEN), 2400 Mol, Belgium
| | - Simon Leekens
- Laboratory for Radiopharmaceutical Research, Department of Pharmacy and Pharmacology, University of Leuven, B-3000 Leuven, Belgium
| | - Christopher Cawthorne
- Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, University of Leuven, 3000 Leuven, Belgium
| | - Filipa Mendes
- C2TN - Centro de Ciências e Tecnologias Nucleares Instituto Superior Técnico, Universidade de Lisboa, 2695-066 Bobadela LRS, Portugal
- DECN - Departamento de Engenharia e Ciências Nucleares, Instituto Superior Técnico, Universidade de Lisboa, 2695-066 Bobadela LRS, Portugal
| | - Célia Fernandes
- C2TN - Centro de Ciências e Tecnologias Nucleares Instituto Superior Técnico, Universidade de Lisboa, 2695-066 Bobadela LRS, Portugal
- DECN - Departamento de Engenharia e Ciências Nucleares, Instituto Superior Técnico, Universidade de Lisboa, 2695-066 Bobadela LRS, Portugal
| | - António Paulo
- C2TN - Centro de Ciências e Tecnologias Nucleares Instituto Superior Técnico, Universidade de Lisboa, 2695-066 Bobadela LRS, Portugal
- DECN - Departamento de Engenharia e Ciências Nucleares, Instituto Superior Técnico, Universidade de Lisboa, 2695-066 Bobadela LRS, Portugal
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Fouillet J, Donzé C, Deshayes E, Santoro L, Rubira L, Fersing C. "One Method to Label Them All": A Single Fully Automated Protocol for GMP-Compliant 68Ga Radiolabeling of PSMA-11, Transposable to PSMA-I&T and PSMA-617. Curr Radiopharm 2024; 17:285-301. [PMID: 38424422 DOI: 10.2174/0118744710293461240219111852] [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: 11/17/2023] [Revised: 01/24/2024] [Accepted: 02/01/2024] [Indexed: 03/02/2024]
Abstract
BACKGROUND Prostate-specific membrane antigen (PSMA) is an ideal target for molecular imaging and targeted radionuclide therapy in prostate cancer. Consequently, various PSMA ligands were developed. Some of these molecules are functionalized with a chelator that can host radiometals, such as 68Ga for PET imaging. The 68Ga radiolabeling step benefits from process automation, making it more robust and reducing radiation exposure. OBJECTIVE To design a single automated radiolabeling protocol for the GMP-compliant preparation of [68Ga]Ga-PSMA-11, transposable to the production of [68Ga]Ga-PSMA-617 and [68Ga]Ga-PSMA-I&T. METHODS A GAIA® synthesis module and a GALLIAD® generator were used. Radio-TLC and radio-HPLC methods were validated for radiochemical purity (RCP) determination. Three [68Ga]Ga-PSMA-11 validation batches were produced and thoroughly tested for appearance and pH, radionuclide identity and purity, RCP, stability, residual solvent and sterility. Minimal modifications were made to the reagents and disposables for optimal application to other PSMA ligands. RESULTS [68Ga]Ga-PSMA-11 for clinical application was produced in 27 min. The 3 validation batches met the quality criteria expected by the European Pharmacopoeia to allow routine production. For optimal transposition to PSMA-617, the solid phase extraction cartridge was changed to improve purification of the radiolabeled product. For application to PSMA-I&T, the buffer solution initially used was replaced by HEPES 2.7 M to achieve good radiochemical yields. Residual HEPES content was checked in the final product and was below the Ph. Eur. threshold. CONCLUSION A single automated radiolabeling method on the GAIA® module was developed and implemented for 68Ga radiolabeling of 3 PSMA ligands, with slight adjustments for each molecule.
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Affiliation(s)
- Juliette Fouillet
- Nuclear Medicine Department, Institut Régional du Cancer de Montpellier (ICM), University of Montpellier, Montpellier, France
| | - Charlotte Donzé
- Nuclear Medicine Department, Institut Régional du Cancer de Montpellier (ICM), University of Montpellier, Montpellier, France
| | - Emmanuel Deshayes
- Nuclear Medicine Department, Institut Régional du Cancer de Montpellier (ICM), University of Montpellier, Montpellier, France
- Institut de Recherche en Cancérologie de Montpellier (IRCM), INSERM U1194, University of Montpellier, Montpellier, France
| | - Lore Santoro
- Nuclear Medicine Department, Institut Régional du Cancer de Montpellier (ICM), University of Montpellier, Montpellier, France
- Institut de Recherche en Cancérologie de Montpellier (IRCM), INSERM U1194, University of Montpellier, Montpellier, France
| | - Léa Rubira
- Nuclear Medicine Department, Institut Régional du Cancer de Montpellier (ICM), University of Montpellier, Montpellier, France
| | - Cyril Fersing
- Nuclear Medicine Department, Institut Régional du Cancer de Montpellier (ICM), University of Montpellier, Montpellier, France
- IBMM, University of Montpellier, CNRS, ENSCM, Montpellier, France
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Ritawidya R, Wongso H, Effendi N, Pujiyanto A, Lestari W, Setiawan H, Humani TS. Lutetium-177-Labeled Prostate-Specific Membrane Antigen-617 for Molecular Imaging and Targeted Radioligand Therapy of Prostate Cancer. Adv Pharm Bull 2023; 13:701-711. [PMID: 38022814 PMCID: PMC10676551 DOI: 10.34172/apb.2023.079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 02/04/2023] [Accepted: 04/24/2023] [Indexed: 12/01/2023] Open
Abstract
Prostate-specific membrane antigen (PSMA) represents a promising target for PSMA-overexpressing diseases, especially prostate cancer-a common type of cancer among men worldwide. In response to the challenges in tackling prostate cancers, several promising PSMA inhibitors from a variety of molecular scaffolds (e.g., phosphorous-, thiol-, and urea-based molecules) have been developed. In addition, PSMA inhibitors bearing macrocyclic chelators have attracted interest due to their favorable pharmacokinetic properties. Recently, conjugating a small PSMA molecule inhibitor-bearing 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) chelator, as exemplified by [177Lu]Lu-PSMA-617 could serve as a molecular imaging probe and targeted radioligand therapy (TRT) of metastatic castration resistant prostate cancer (mCRPC). Hence, studies related to mCRPC have drawn global attention. In this review, the recent development of PSMA ligand-617-labeled with 177Lu for the management of mCRPC is presented. Its molecular mechanism of action, safety, efficacy, and future direction are also described.
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Affiliation(s)
- Rien Ritawidya
- Research Center for Radioisotope, Radiopharmaceutical, and Biodosimetry Technology, National Research and Innovation Agency (BRIN), Kawasan Puspiptek, Setu, Tangerang Selatan, 15314 Indonesia
- Research Collaboration Center for Theranostic Radiopharmaceuticals, National Research and Innovation Agency, Jl. Raya Bandung-Sumedang KM 21, Sumedang, 45363, Indonesia
| | - Hendris Wongso
- Research Center for Radioisotope, Radiopharmaceutical, and Biodosimetry Technology, National Research and Innovation Agency (BRIN), Kawasan Puspiptek, Setu, Tangerang Selatan, 15314 Indonesia
- Research Collaboration Center for Theranostic Radiopharmaceuticals, National Research and Innovation Agency, Jl. Raya Bandung-Sumedang KM 21, Sumedang, 45363, Indonesia
| | - Nurmaya Effendi
- Faculty of Pharmacy, University of Muslim Indonesia, Kampus II UMI, Jl. Urip Sumoharjo No.225, Panaikang, Panakkukang, Kota, Makassar, Sulawesi Selatan 90231
| | - Anung Pujiyanto
- Research Center for Radioisotope, Radiopharmaceutical, and Biodosimetry Technology, National Research and Innovation Agency (BRIN), Kawasan Puspiptek, Setu, Tangerang Selatan, 15314 Indonesia
| | - Wening Lestari
- Research Center for Radioisotope, Radiopharmaceutical, and Biodosimetry Technology, National Research and Innovation Agency (BRIN), Kawasan Puspiptek, Setu, Tangerang Selatan, 15314 Indonesia
| | - Herlan Setiawan
- Research Center for Radioisotope, Radiopharmaceutical, and Biodosimetry Technology, National Research and Innovation Agency (BRIN), Kawasan Puspiptek, Setu, Tangerang Selatan, 15314 Indonesia
| | - Titis Sekar Humani
- Research Center for Radioisotope, Radiopharmaceutical, and Biodosimetry Technology, National Research and Innovation Agency (BRIN), Kawasan Puspiptek, Setu, Tangerang Selatan, 15314 Indonesia
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Konrad M, Rinscheid A, Wienand G, Nittbaur B, Wester HJ, Janzen T, Lapa C, Pfob CH, Schottelius M. [ 99mTc]Tc-PentixaTec: development, extensive pre-clinical evaluation, and first human experience. Eur J Nucl Med Mol Imaging 2023; 50:3937-3948. [PMID: 37597009 PMCID: PMC10611619 DOI: 10.1007/s00259-023-06395-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: 06/02/2023] [Accepted: 08/05/2023] [Indexed: 08/21/2023]
Abstract
PURPOSE The clinical success non-invasive imaging of CXCR4 expression using [68 Ga]Ga-PentixaFor-PET warrants an expansion of the targeting concept towards conventional scintigraphy/SPECT with their lower cost and general availability. To this aim, we developed and comparatively evaluated a series of 99mTc-labeled cyclic pentapeptides based on the PentixaFor scaffold. METHODS Six mas3-conjugated CPCR4 analogs with different 4-aminobenzoic acid (Abz)-D-Ala-D-Arg-aa3 linkers (L1-L6) as well as the corresponding HYNIC- and N4-analogs of L6-CPCR4 were synthesized via standard SPPS. Competitive binding studies (IC50 and IC50inv) were carried out using Jurkat T cell lymphoma cells and [125I]FC-131 as radioligand. Internalization kinetics were investigated using hCXCR4-overexpressing Chem-1 cells. Biodistribution studies and small animal SPECT/CT imaging (1 h p.i.) were carried out using Jurkat xenograft bearing CB17/SCID mice. Based on the preclinical results, [99mTc]Tc-N4-L6-CPCR4 ([99mTc]Tc-PentixaTec) was selected for an early translation to the human setting. Five patients with hematologic malignancies underwent [99mTc]Tc-N4-L6-CPCR4 SPECT/planar imaging with individual dosimetry. RESULTS Of the six mas3-conjugated peptides, mas3-L6-CPCR4 (mas3-dap-r-a-Abz-CPCR4) showed the highest CXCR4 affinity (IC50 = 5.0 ± 1.3 nM). Conjugation with N4 (N4-L6-CPCR4) further improved hCXCR4 affinity to 0.6 ± 0.1 nM. [99mTc]Tc-N4-L6-CPCR4 also showed the most efficient internalization (97% of total cellular activity at 2 h) and the highest tumor accumulation (8.6 ± 1.3% iD/g, 1 h p.i.) of the compounds investigated. Therefore, [99mTc]Tc-N4-L6-CPCR4 (termed [99mTc]Tc-PentixaTec) was selected for first-in-human application. [99mTc]Tc-PentixaTec was well tolerated, exhibits a favorable biodistribution and dosimetry profile (2.1-3.4 mSv per 500 MBq) and excellent tumor/background ratios in SPECT and planar imaging. CONCLUSION The successive optimization of the amino acid composition of the linker structure and the N-terminal 99mTc-labeling strategies (mas3 vs HYNIC vs N4) has provided [99mTc]Tc-PentixaTec as a novel, highly promising CXCR4-targeted SPECT agent for clinical application. With its excellent CXCR4 affinity, efficient internalization, high uptake in CXCR4-expressing tissues, suitable clearance/biodistribution characteristics, and favorable human dosimetry, it holds great potential for further clinical use.
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Affiliation(s)
- Matthias Konrad
- Chair for Pharmaceutical Radiochemistry, Faculties of Chemistry and Medicine, Technische Universität München, 85748, Garching, Germany
| | - Andreas Rinscheid
- Medical Physics and Radiation Protection, University Hospital Augsburg, Stenglinstrasse 2, 86156, Augsburg, Germany
| | - Georgine Wienand
- Nuclear Medicine, Faculty of Medicine, University of Augsburg, Stenglinstrasse 2, 86156, Augsburg, Germany
| | - Bernd Nittbaur
- Nuclear Medicine, Faculty of Medicine, University of Augsburg, Stenglinstrasse 2, 86156, Augsburg, Germany
| | - Hans-Jürgen Wester
- Chair for Pharmaceutical Radiochemistry, Faculties of Chemistry and Medicine, Technische Universität München, 85748, Garching, Germany
| | - Tilman Janzen
- Medical Physics and Radiation Protection, University Hospital Augsburg, Stenglinstrasse 2, 86156, Augsburg, Germany
| | - Constantin Lapa
- Nuclear Medicine, Faculty of Medicine, University of Augsburg, Stenglinstrasse 2, 86156, Augsburg, Germany
| | - Christian Helmut Pfob
- Nuclear Medicine, Faculty of Medicine, University of Augsburg, Stenglinstrasse 2, 86156, Augsburg, Germany.
| | - Margret Schottelius
- Translational Radiopharmaceutical Sciences, Department of Nuclear Medicine and Department of Oncology, Centre Hospitalier Universitaire Vaudois (CHUV) and University of Lausanne (UNIL), Rue du Bugnon 25A, Agora, CH-1011, Lausanne, Switzerland.
- AGORA, Pôle de Recherche Sur Le Cancer, 1011, Lausanne, Switzerland.
- SCCL Swiss Cancer Center Leman, 1011, Lausanne, Switzerland.
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Hohberg M, Reifegerst M, Drzezga A, Wild M, Schmidt M. Prediction of Response to 177Lu-PSMA Therapy Based on Tumor-to-Kidney Ratio on Pretherapeutic PSMA PET/CT and Posttherapeutic Tumor-Dose Evaluation in mCRPC. J Nucl Med 2023; 64:1758-1764. [PMID: 37652546 DOI: 10.2967/jnumed.122.264953] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 07/25/2023] [Indexed: 09/02/2023] Open
Abstract
The aim of this study was to analyze the absorbed dose of 177Lu-PSMA in osseous versus lymphatic metastases in patients with metastatic castration-resistant prostate cancer across therapy cycles and to relate those data to therapeutic success. In addition, pretherapeutic prostate-specific membrane antigen (PSMA) PET/CT was evaluated for its ability to predict response behavior. Methods: The study comprised 30 patients with metastatic castration-resistant prostate cancer, each receiving at least 3 cycles of 177Lu-PSMA therapy. Prostate-specific antigen (PSA) values between baseline and 6 wk after the third therapy cycle were used to classify the patients as responders (PSA decline ≥ 50%) or nonresponders (unchanged or increasing PSA level). Quantitative SPECT/CT images were acquired 24, 48, and 168 h after application of 177Lu-PSMA. The absorbed dose for tumor lesions was calculated with dosimetry software. From the pretherapeutic PET/CT scan, the tumor-to-kidney uptake ratio was determined for different SUVs. Results: Regardless of patient response, the kidneys received a mean dose of 0.55 ± 0.20 Gy/GBq per cycle. In the first therapy cycle, the lymph node lesions received a mean dose of 3.73 ± 1.65 Gy/GBq in responders and 1.86 ± 1.25 Gy/GBq in nonresponders (P < 0.01). For bone lesions, the respective mean doses were 3.47 ± 2.00 Gy/GBq and 1.48 ± 0.95 Gy/GBq (P < 0.01). When successive therapy cycles were compared, the mean dose was found to have been reduced from the first to the second cycle by 27% for lymph nodes and by 33% for bone lesions. A significant difference (P < 0.01) in the ratio of lymph node and bone lesion uptake to kidney uptake between responders and nonresponders could be deduced from the pretherapeutic PET/CT scan. Conclusion: Significantly higher doses were achieved for lymph node and bone lesions in responders. The highest absorbed dose, for both lymphatic and osseous lesions, was achieved in the first cycle, decreasing in the second therapy cycle thereafter despite unchanged therapy activities. It may be possible to estimate the response to therapy from the ratio of tumor uptake to kidney uptake obtained from the pretherapeutic PSMA PET/CT scans.
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Affiliation(s)
- Melanie Hohberg
- Department of Nuclear Medicine and Cancer Center Cologne, University Hospital of Cologne, Cologne, Germany
| | - Manuel Reifegerst
- Department of Nuclear Medicine and Cancer Center Cologne, University Hospital of Cologne, Cologne, Germany
| | - Alexander Drzezga
- Department of Nuclear Medicine and Cancer Center Cologne, University Hospital of Cologne, Cologne, Germany
| | - Markus Wild
- Department of Nuclear Medicine and Cancer Center Cologne, University Hospital of Cologne, Cologne, Germany
| | - Matthias Schmidt
- Department of Nuclear Medicine and Cancer Center Cologne, University Hospital of Cologne, Cologne, Germany
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9
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Chen Y, Zhang X, Ni M, Gao X, Wang X, Xie Q, Zhang J, Cui M. Synthesis, Preclinical Evaluation, and First-in-Human PET Study of [ 68Ga]-Labeled Biphenyl-Containing PSMA Tracers. J Med Chem 2023; 66:13332-13345. [PMID: 37708404 DOI: 10.1021/acs.jmedchem.3c01475] [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: 09/16/2023]
Abstract
Radioisotope-labeled prostate-specific membrane antigen (PSMA) PET tracers have gained popularity in diagnosing prostate cancer (PCa). This study aimed to improve the affinity and tumor-targeting capabilities of new PSMA tracers by increasing the number of pharmacophores that specifically bind to PSMA. Using biphenyl as a core scaffold, we investigated the relationship among spacer segments, affinity, and pharmacokinetic properties. In preclinical PET studies on mice with 22Rv1 tumors, compared with [68Ga]Ga-PSMA-11 (SUVmax = 3.37), [68Ga]Ga-PSMA-D5 (Ki = 0.15) showed higher tumor uptake (SUVmax = 3.51) and lower renal uptake (T/K = 1.84). In the first-in-human study, [68Ga]Ga-PSMA-D5 effectively detected small PCa-associated lesions and distant metastases. The advantages of [68Ga]Ga-PSMA-D5 include high tumor uptake, straightforward synthesis, and labeling, making it a promising PSMA PET tracer. Furthermore, [68Ga]Ga-PSMA-D5 contains a DOTA chelator, allowing convenient labeling with therapeutic radionuclides such as 177Lu and 225Ac, providing the potential for targeted radioligand therapy in PCa.
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Affiliation(s)
- Yimin Chen
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Xiaojun Zhang
- Department of Nuclear Medicine, Chinese PLA General Hospital, Beijing 100853, China
| | - Ming Ni
- Department of Nuclear Medicine, Division of Life Sciences and Medicine, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei 230001, China
| | - Xi Gao
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Xinlin Wang
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Qiang Xie
- Department of Nuclear Medicine, Division of Life Sciences and Medicine, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei 230001, China
| | - Jinming Zhang
- Department of Nuclear Medicine, Chinese PLA General Hospital, Beijing 100853, China
| | - Mengchao Cui
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
- Center for Advanced Materials Research, Beijing Normal University at Zhuhai, Zhuhai 519087, China
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10
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Gade N, Kaur J, Bhardwaj A, Ebrahimi E, Dufour J, Wuest M, Wuest F. N-Alkyl Carbamoylimidazoles as Versatile Synthons for the Synthesis of Urea-Based PSMA Inhibitors. ACS Med Chem Lett 2023; 14:943-948. [PMID: 37465305 PMCID: PMC10351058 DOI: 10.1021/acsmedchemlett.3c00087] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 06/07/2023] [Indexed: 07/20/2023] Open
Abstract
We describe N-alkyl carbamoylimidazoles as readily available and highly versatile synthons for synthesizing urea-based prostate-specific membrane antigen (PSMA) inhibitors. Urea formation proceeded in high yields (>80%) at room temperature under aqueous conditions. All novel compounds were tested for their PSMA inhibitory potency in a cell-based radiometric binding assay. Compound 17 was identified as a novel high-affinity PSMA inhibitor (IC50 = 0.013 μM) suitable for developing an 18F-labeled radioligand for PET imaging of PSMA in prostate cancer.
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Affiliation(s)
- Narendar
Reddy Gade
- Department
of Oncology, University of Alberta, Edmonton, Alberta T6G 1Z2, Canada
| | - Jatinder Kaur
- Department
of Oncology, University of Alberta, Edmonton, Alberta T6G 1Z2, Canada
| | - Atul Bhardwaj
- Department
of Oncology, University of Alberta, Edmonton, Alberta T6G 1Z2, Canada
| | - Edris Ebrahimi
- Department
of Oncology, University of Alberta, Edmonton, Alberta T6G 1Z2, Canada
| | - Jennifer Dufour
- Department
of Oncology, University of Alberta, Edmonton, Alberta T6G 1Z2, Canada
| | - Melinda Wuest
- Department
of Oncology, University of Alberta, Edmonton, Alberta T6G 1Z2, Canada
| | - Frank Wuest
- Department
of Oncology, University of Alberta, Edmonton, Alberta T6G 1Z2, Canada
- Faculty
of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta T6G 2H1, Canada
- Department
of Chemistry, University of Alberta, Edmonton, Alberta T6G 2R3, Canada
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11
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Hotta M, Gafita A, Murthy V, Benz MR, Sonni I, Burger IA, Eiber M, Emmett L, Farolfi A, Fendler WP, Weber MM, Hofman MS, Hope TA, Kratochwil C, Czernin J, Calais J. PSMA PET Tumor-to-Salivary Gland Ratio to Predict Response to [ 177Lu]PSMA Radioligand Therapy: An International Multicenter Retrospective Study. J Nucl Med 2023; 64:1024-1029. [PMID: 36997329 DOI: 10.2967/jnumed.122.265242] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 02/10/2023] [Accepted: 02/10/2023] [Indexed: 04/01/2023] Open
Abstract
Prostate-specific membrane antigen (PSMA)-targeted radioligand therapy can improve the outcome of patients with advanced metastatic castration-resistant prostate cancer, but patients do not respond uniformly. We hypothesized that using the salivary glands as a reference organ can enable selective patient stratification. We aimed to establish a PSMA PET tumor-to-salivary gland ratio (PSG score) to predict outcomes after [177Lu]PSMA. Methods: In total, 237 men with metastatic castration-resistant prostate cancer treated with [177Lu]PSMA were included. A quantitative PSG (qPSG) score (SUVmean ratio of whole-body tumor to parotid glands) was semiautomatically calculated on baseline [68Ga]PSMA-11 PET images. Patients were divided into 3 groups: high (qPSG > 1.5), intermediate (qPSG = 0.5-1.5), and low (qPSG < 0.5) scores. Ten readers interpreted the 3-dimensional maximum-intensity-projection baseline [68Ga]PSMA-11 PET images and classified patients into 3 groups based on visual PSG (vPSG) score: high (most of the lesions showed higher uptake than the parotid glands) intermediate (neither low nor high), and low (most of the lesions showed lower uptake than the parotid glands). Outcome data included a more than 50% prostate-specific antigen decline, prostate-specific antigen (PSA) progression-free survival, and overall survival (OS). Results: Of the 237 patients, the numbers in the high, intermediate, and low groups were 56 (23.6%), 163 (68.8%), and 18 (7.6%), respectively, for qPSG score and 106 (44.7%), 96 (40.5%), and 35 (14.8%), respectively, for vPSG score. The interreader reproducibility of the vPSG score was substantial (Fleiss weighted κ, 0.68). The more than 50% prostate-specific antigen decline was better in patients with a higher PSG score (high vs. intermediate vs. low, 69.6% vs. 38.7% vs. 16.7%, respectively, for qPSG [P < 0.001] and 63.2% vs 33.3% vs 16.1%, respectively, for vPSG [P < 0.001]). The median PSA progression-free survival of the high, intermediate, and low groups by qPSG score was 7.2, 4.0, and 1.9 mo (P < 0.001), respectively, by qPSG score and 6.7, 3.8, and 1.9 mo (P < 0.001), respectively, by vPSG score. The median OS of the high, intermediate, and low groups was 15.0, 11.2, and 13.9 mo (P = 0.017), respectively, by qPSG score and 14.3, 9.6, and 12.9 mo (P = 0.018), respectively, by vPSG score. Conclusion: The PSG score was prognostic for PSA response and OS after [177Lu]PSMA. The visual PSG score assessed on 3-dimensional maximum-intensity-projection PET images yielded substantial reproducibility and comparable prognostic value to the quantitative score.
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Affiliation(s)
- Masatoshi Hotta
- Ahmanson Translational Theranostics Division, UCLA, Los Angeles, California;
| | - Andrei Gafita
- Ahmanson Translational Theranostics Division, UCLA, Los Angeles, California
| | - Vishnu Murthy
- Ahmanson Translational Theranostics Division, UCLA, Los Angeles, California
| | - Matthias R Benz
- Ahmanson Translational Theranostics Division, UCLA, Los Angeles, California
| | - Ida Sonni
- Ahmanson Translational Theranostics Division, UCLA, Los Angeles, California
| | - Irene A Burger
- Department of Nuclear Medicine, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Matthias Eiber
- Department of Nuclear Medicine, Technical University Munich, Munich, Germany
| | - Louise Emmett
- Department of Theranostics and Nuclear Medicine, St. Vincent's Hospital, Sydney, New South Wales, Australia
| | - Andrea Farolfi
- Ahmanson Translational Theranostics Division, UCLA, Los Angeles, California
- Nuclear Medicine, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Wolfgang P Fendler
- Department of Nuclear Medicine, University of Duisburg-Essen and German Cancer Consortium-University Hospital Essen, Essen, Germany
| | - Manuel M Weber
- Department of Nuclear Medicine, University of Duisburg-Essen and German Cancer Consortium-University Hospital Essen, Essen, Germany
| | - Michael S Hofman
- Prostate Cancer Theranostics and Imaging Centre of Excellence, Molecular Imaging Therapeutic Nuclear Medicine, Cancer Imaging, Peter MacCallum Cancer Centre, and Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Victoria, Australia
| | - Thomas A Hope
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California; and
| | - Clemens Kratochwil
- Department of Nuclear Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Johannes Czernin
- Ahmanson Translational Theranostics Division, UCLA, Los Angeles, California
| | - Jeremie Calais
- Ahmanson Translational Theranostics Division, UCLA, Los Angeles, California
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12
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Tauber R, Knorr K, Retz M, Rauscher I, Grigorascu S, Hansen K, D'Alessandria C, Wester HJ, Gschwend J, Weber W, Eiber M, Langbein T. Safety and Efficacy of [ 177Lu]-PSMA-I&T Radioligand Therapy in Octogenarians with Metastatic Castration-Resistant Prostate Cancer: Report on 80 Patients over the Age of 80 Years. J Nucl Med 2023:jnumed.122.265259. [PMID: 37321824 DOI: 10.2967/jnumed.122.265259] [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: 12/06/2022] [Revised: 03/14/2023] [Indexed: 06/17/2023] Open
Abstract
177Lu-labeled prostate-specific membrane antigen (PSMA) radioligand therapy (RLT) is a new treatment option for metastatic castration-resistant prostate cancer (mCRPC). Its low toxicity profile favors use in elderly patients or in patients with critical comorbidities. The purpose of this analysis was to evaluate the efficacy and safety of [177Lu]-PSMA RLT in mCRPC patients at least 80 y old. Methods: Eighty mCRPC patients at least 80 y old underwent [177Lu]-PSMA-I&T RLT and were retrospectively selected. The patients were previously treated by androgen receptor-directed therapy, received taxane-based chemotherapy, or were chemotherapy-ineligible. The best prostate-specific antigen (PSA) response was calculated, as well as clinical progression-free survival (cPFS) and overall survival (OS). Toxicity data were acquired until 6 mo after the last treatment cycle. Results: Of 80 patients, 49 (61.3%) were chemotherapy-naïve and 16 (20%) had visceral metastases. The median number of previous mCRPC treatment regimens was 2. In total, 324 cycles (median, 4 cycles; range, 1-12) with a median cumulative activity of 23.8 GBq (interquartile range, 14.8-42.2) were applied. A PSA decline of 50% was achieved in 37 (46.3%) patients. Chemotherapy-naïve patients showed higher 50% PSA response rates than chemotherapy-pretreated patients (51.0% vs. 38.7%, respectively). Overall, median cPFS and OS were 8.7 and 16.1 mo, respectively. The median cPFS and OS of chemotherapy-naïve patients were significantly longer than those of chemotherapy-pretreated patients (10.5 vs. 6.5 mo and 20.7 vs. 11.8 mo, respectively, P < 0.05). A lower hemoglobin level and higher lactate dehydrogenase level at baseline were independent predictors of shorter cPFS and OS. Treatment-emergent grade 3 toxicities were anemia in 4 patients (5%), thrombocytopenia in 3 patients (3.8%), and renal impairment in 4 patients (5%). No nonhematologic grade 3 and no grade 4 toxicities were observed. The most frequent clinical side effects were grade 1-2 xerostomia, fatigue, and inappetence. Conclusion: [177Lu]-PSMA-I&T RLT in mCRPC patients at least 80 y old is safe and effective, comparable to previously published data on non-age-selected cohorts with a low rate of high-grade toxicities. Chemotherapy-naïve patients showed a better and longer response to therapy than taxane-pretreated patients. [177Lu]-PSMA RLT seems to be a meaningful treatment option for older patients.
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Affiliation(s)
- Robert Tauber
- Department of Urology, Klinikum Rechts der Isar, School of Medicine, Technical University of Munich, Munich, Germany;
| | - Karina Knorr
- Department of Nuclear Medicine, Klinikum Rechts der Isar, School of Medicine, Technical University of Munich, Munich, Germany; and
| | - Margitta Retz
- Department of Urology, Klinikum Rechts der Isar, School of Medicine, Technical University of Munich, Munich, Germany
| | - Isabel Rauscher
- Department of Nuclear Medicine, Klinikum Rechts der Isar, School of Medicine, Technical University of Munich, Munich, Germany; and
| | - Sonia Grigorascu
- Department of Nuclear Medicine, Klinikum Rechts der Isar, School of Medicine, Technical University of Munich, Munich, Germany; and
| | - Kimberley Hansen
- Department of Nuclear Medicine, Klinikum Rechts der Isar, School of Medicine, Technical University of Munich, Munich, Germany; and
| | - Calogero D'Alessandria
- Department of Nuclear Medicine, Klinikum Rechts der Isar, School of Medicine, Technical University of Munich, Munich, Germany; and
| | | | - Jürgen Gschwend
- Department of Urology, Klinikum Rechts der Isar, School of Medicine, Technical University of Munich, Munich, Germany
| | - Wolfgang Weber
- Department of Nuclear Medicine, Klinikum Rechts der Isar, School of Medicine, Technical University of Munich, Munich, Germany; and
| | - Matthias Eiber
- Department of Nuclear Medicine, Klinikum Rechts der Isar, School of Medicine, Technical University of Munich, Munich, Germany; and
| | - Thomas Langbein
- Department of Nuclear Medicine, Klinikum Rechts der Isar, School of Medicine, Technical University of Munich, Munich, Germany; and
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13
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Karimzadeh A, Heck M, Tauber R, Solaris E, Nekolla S, Knorr K, Haller B, D'Alessandria C, Weber WA, Eiber M, Rauscher I. The Impact of PSMA PET-Based Eligibility Criteria Used in the Prospective Phase II TheraP Trial in Metastatic Castration-Resistant Prostate Cancer Patients Undergoing Prostate-Specific Membrane Antigen-Targeted Radioligand Therapy. J Nucl Med 2023:jnumed.122.265346. [PMID: 37290796 DOI: 10.2967/jnumed.122.265346] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 03/24/2023] [Indexed: 06/10/2023] Open
Abstract
Prostate-specific membrane antigen (PSMA) radioligand therapy (RLT) has shown encouraging results for treatment of metastatic castration-resistant prostate cancer (mCRPC) in the prospective, multicenter, randomized phase II TheraP study. The inclusion criteria for that study comprised a pretherapeutic 68Ga-PSMA-11 PET scan showing sufficient tumor uptake using a predefined threshold and the absence of 18F-FDG-positive, PSMA ligand-negative tumor lesions. However, the prognostic value of these PET-based inclusion criteria remains unclear. Therefore, we evaluated the outcome of mCRPC patients treated with PSMA RLT using TheraP as well as other TheraP-based PET inclusion criteria. Methods: First, patients were dichotomized into 2 groups whose PSMA PET scans did (TheraP contrast-enhanced PSMA [cePSMA] PET-positive) or did not (TheraP cePSMA PET-negative) fulfill the inclusion criteria of TheraP. Notably, unlike in TheraP, 18F-FDG PET was not performed on our patients. Prostate-specific antigen (PSA) response (PSA decline ≥ 50% from baseline), PSA progression-free survival, and overall survival (OS) were compared. Additionally, patients were further dichotomized according to predefined SUVmax thresholds different from those used in TheraP to analyze their potential impact on outcome as well. Results: In total, 107 mCRPC patients were included in this analysis (TheraP cePSMA PET-positive, n = 77; TheraP cePSMA PET-negative, n = 30). PSA response rates were higher in TheraP cePSMA PET-positive patients than in TheraP cePSMA PET-negative patients (54.5% vs. 20%, respectively; P = 0.0012). The median PSA progression-free survival (P = 0.007) and OS (P = 0.0007) of patients were significantly longer in the TheraP cePSMA PET-positive group than in the TheraP cePSMA PET-negative group. Moreover, being in the TheraP cePSMA PET-positive group was identified as a significant prognosticator of longer OS (P = 0.003). The application of different SUVmax thresholds for a single hottest lesion demonstrated no influence on outcome in patients eligible for PSMA RLT. Conclusion: Patient selection for PSMA RLT according to the inclusion criteria of TheraP led to a better treatment response and outcome in our preselected patient cohort. However, a relevant number of patients not fulfilling these criteria also showed substantial rates of response.
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Affiliation(s)
- Amir Karimzadeh
- Department of Nuclear Medicine, School of Medicine, Technical University of Munich, Munich, Germany;
- Department of Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Matthias Heck
- Department of Urology, School of Medicine, Technical University of Munich, Munich, Germany; and
| | - Robert Tauber
- Department of Urology, School of Medicine, Technical University of Munich, Munich, Germany; and
| | - Esteban Solaris
- Department of Nuclear Medicine, School of Medicine, Technical University of Munich, Munich, Germany
| | - Stephan Nekolla
- Department of Nuclear Medicine, School of Medicine, Technical University of Munich, Munich, Germany
| | - Karina Knorr
- Department of Nuclear Medicine, School of Medicine, Technical University of Munich, Munich, Germany
| | - Bernhard Haller
- Institute of AI and Informatics in Medicine, School of Medicine, Technical University of Munich, Munich, Germany
| | - Calogero D'Alessandria
- Department of Nuclear Medicine, School of Medicine, Technical University of Munich, Munich, Germany
| | - Wolfgang A Weber
- Department of Nuclear Medicine, School of Medicine, Technical University of Munich, Munich, Germany
| | - Matthias Eiber
- Department of Nuclear Medicine, School of Medicine, Technical University of Munich, Munich, Germany
| | - Isabel Rauscher
- Department of Nuclear Medicine, School of Medicine, Technical University of Munich, Munich, Germany
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14
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Murce E, Beekman S, Spaan E, Handula M, Stuurman D, de Ridder C, Seimbille Y. Preclinical Evaluation of a PSMA-Targeting Homodimer with an Optimized Linker for Imaging of Prostate Cancer. Molecules 2023; 28:molecules28104022. [PMID: 37241763 DOI: 10.3390/molecules28104022] [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: 04/21/2023] [Revised: 05/08/2023] [Accepted: 05/09/2023] [Indexed: 05/28/2023] Open
Abstract
Prostate-specific membrane antigen (PSMA) targeting radiopharmaceuticals have been successfully used for diagnosis and therapy of prostate cancer. Optimization of the available agents is desirable to improve tumor uptake and reduce side effects to non-target organs. This can be achieved, for instance, via linker modifications or multimerization approaches. In this study, we evaluated a small library of PSMA-targeting derivatives with modified linker residues, and selected the best candidate based on its binding affinity to PSMA. The lead compound was coupled to a chelator for radiolabeling, and subject to dimerization. The resulting molecules, 22 and 30, were highly PSMA specific (IC50 = 1.0-1.6 nM) and stable when radiolabeled with indium-111 (>90% stable in PBS and mouse serum up to 24 h). Moreover, [111In]In-30 presented a high uptake in PSMA expressing LS174T cells, with 92.6% internalization compared to 34.1% for PSMA-617. Biodistribution studies in LS174T mice xenograft models showed that [111In]In-30 had a higher tumor and kidney uptake compared to [111In]In-PSMA-617, but increasing T/K and T/M ratios at 24 h p.i. Tumors could be clearly visualized at 1 h p.i. by SPECT/CT after administration of [111In]In-22 and [111In]In-PSMA-617, while [111In]In-30 showed a clear signal at later time-points (e.g., 24 h p.i.).
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Affiliation(s)
- Erika Murce
- Department of Radiology and Nuclear Medicine, University Medical Center Rotterdam, Erasmus MC, 3015 GD Rotterdam, The Netherlands
- Erasmus MC Cancer Institute, 3015 GD Rotterdam, The Netherlands
| | - Savanne Beekman
- Department of Radiology and Nuclear Medicine, University Medical Center Rotterdam, Erasmus MC, 3015 GD Rotterdam, The Netherlands
- Erasmus MC Cancer Institute, 3015 GD Rotterdam, The Netherlands
| | - Evelien Spaan
- Department of Radiology and Nuclear Medicine, University Medical Center Rotterdam, Erasmus MC, 3015 GD Rotterdam, The Netherlands
- Erasmus MC Cancer Institute, 3015 GD Rotterdam, The Netherlands
| | - Maryana Handula
- Department of Radiology and Nuclear Medicine, University Medical Center Rotterdam, Erasmus MC, 3015 GD Rotterdam, The Netherlands
- Erasmus MC Cancer Institute, 3015 GD Rotterdam, The Netherlands
| | - Debra Stuurman
- Department of Radiology and Nuclear Medicine, University Medical Center Rotterdam, Erasmus MC, 3015 GD Rotterdam, The Netherlands
- Erasmus MC Cancer Institute, 3015 GD Rotterdam, The Netherlands
| | - Corrina de Ridder
- Department of Radiology and Nuclear Medicine, University Medical Center Rotterdam, Erasmus MC, 3015 GD Rotterdam, The Netherlands
- Erasmus MC Cancer Institute, 3015 GD Rotterdam, The Netherlands
| | - Yann Seimbille
- Department of Radiology and Nuclear Medicine, University Medical Center Rotterdam, Erasmus MC, 3015 GD Rotterdam, The Netherlands
- Erasmus MC Cancer Institute, 3015 GD Rotterdam, The Netherlands
- Life Sciences Division, TRIUMF, Vancouver, BC V6T 2A3, Canada
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15
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Kraihammer M, Garnuszek P, Bauman A, Maurin M, Alejandre Lafont M, Haubner R, von Guggenberg E, Gabriel M, Decristoforo C. Improved quality control of [ 177Lu]Lu-PSMA I&T. EJNMMI Radiopharm Chem 2023; 8:7. [PMID: 36971890 PMCID: PMC10043144 DOI: 10.1186/s41181-023-00191-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 03/13/2023] [Indexed: 03/29/2023] Open
Abstract
BACKGROUND Targeted radionuclide therapy with [177Lu]Lu-PSMA I&T (zadavotide guraxetan) has proven high efficacy and safety in treating patients with advanced prostate cancer worldwide. Several methods to determine the radiochemical purity have been reported but also limitations in the HPLC analysis due to retention of the sample and tailing effects when using standard gradients containing trifluoroacetic acid (TFA). We here report on the validation of a method for quality control of [177Lu]Lu-PSMA I&T including determination of radiochemical purity, identity testing and limit test for PSMA I&T by HPLC using a Phosphate buffer /Acetonitrile gradient system, complemented with a TLC system with 0.1N Citrate buffer pH 5 as mobile phase including validation of the methods, batch and stability data as well as identification of the main radiochemical impurity by mass spectrometry. RESULTS The described HPLC method met the defined acceptance criteria in terms of accuracy, specificity, robustness, linearity, range and LOQ. HPLC analysis revealed symmetrical peaks and quantitative recovery from the column. Batch data showed a radiochemical purity > 95% as determined by HPLC, stability data a pronounced degradation due to radiolysis, which could be limited by addition of ascorbic acid, dilution and storage at low temperatures. The main radiochemical impurity was found to be the de-iodinated form of [177Lu]Lu-PSMA I&T. TLC analysis allowed to determine the amount of free Lu-177 even in the presence of DTPA in the final formulation. CONCLUSION Overall the described combination of HPLC and TLC provides a reliable tool for quality control of [177Lu]Lu-PSMA I&T.
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Affiliation(s)
- Martin Kraihammer
- Department of Nuclear Medicine, Medical University Innsbruck, Anichstr. 35, 6020, Innsbruck, Austria
- Department of Nuclear Medicine and Endocrinology, Kepler University Hospital, Linz, Austria
| | - Piotr Garnuszek
- Radioisotope Centre POLATOM, National Centre for Nuclear Research, Otwock, Poland
| | - Andreas Bauman
- Division of Radiopharmaceutical Chemistry, University Hospital Basel, Basel, Switzerland
| | - Michael Maurin
- Radioisotope Centre POLATOM, National Centre for Nuclear Research, Otwock, Poland
| | | | - Roland Haubner
- Department of Nuclear Medicine, Medical University Innsbruck, Anichstr. 35, 6020, Innsbruck, Austria
| | - Elisabeth von Guggenberg
- Department of Nuclear Medicine, Medical University Innsbruck, Anichstr. 35, 6020, Innsbruck, Austria
| | - Michael Gabriel
- Department of Nuclear Medicine and Endocrinology, Kepler University Hospital, Linz, Austria
| | - Clemens Decristoforo
- Department of Nuclear Medicine, Medical University Innsbruck, Anichstr. 35, 6020, Innsbruck, Austria.
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16
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Kepenek F, Can C, Kömek H, Kaplan İ, Gündoğan C, Ebinç S, Güzel Y, Agüloglu N, Karaoglan H, Taşdemir B. Combination of [68Ga]Ga-PSMA PET/CT and [18F]FDG PET/CT in demonstrating dedifferentiation in castration-resistant prostate cancer. MÉDECINE NUCLÉAIRE 2023. [DOI: 10.1016/j.mednuc.2022.12.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
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17
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Kunert JP, Müller M, Günther T, Stopper L, Urtz-Urban N, Beck R, Wester HJ. Synthesis and preclinical evaluation of novel 99mTc-labeled PSMA ligands for radioguided surgery of prostate cancer. EJNMMI Res 2023; 13:2. [PMID: 36645586 PMCID: PMC9842843 DOI: 10.1186/s13550-022-00942-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 10/15/2022] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND Radioguided surgery (RGS) has recently emerged as a valuable new tool in the management of recurrent prostate cancer (PCa). After preoperative injection of a 99mTc-labeled prostate-specific membrane antigen (PSMA) inhibitor, radioguided intraoperative identification and resection of lesions is facilitated by means of suitable γ-probes. First clinical experiences show the feasibility of RGS and suggest superiority over conventional lymph node dissection in recurrent PCa. However, commonly used [99mTc]Tc-PSMA-I&S exhibits slow whole-body clearance, thus hampering optimal tumor-to-background ratios (TBR) during surgery. We therefore aimed to develop novel 99mTc-labeled, PSMA-targeted radioligands with optimized pharmacokinetic profile to increase TBR at the time of surgery. METHODS Three 99mTc-labeled N4-PSMA ligands were preclinically evaluated and compared to [99mTc]Tc-PSMA-I&S. PSMA affinity (IC50) and internalization were determined on LNCaP cells. Lipophilicity was assessed by means of the distribution coefficient logD7.4 and an ultrafiltration method was used to determine binding to human plasma proteins. Biodistribution studies and static µSPECT/CT-imaging were performed at 6 h p.i. on LNCaP tumor-bearing CB17-SCID mice. RESULTS The novel N4-PSMA tracers were readily labeled with [99mTc]TcO4- with RCP > 95%. Comparable and high PSMA affinity was observed for all [99mTc]Tc-N4-PSMA-ligands. The ligands showed variable binding to human plasma and medium to low lipophilicity (logD7.4 - 2.6 to - 3.4), both consistently decreased compared to [99mTc]Tc-PSMA-I&S. Biodistribution studies revealed comparable tumor uptake among all [99mTc]Tc-N4-PSMA-ligands and [99mTc]Tc-PSMA-I&S, while clearance from most organs was superior for the novel tracers. Accordingly, increased TBR were achieved. [99mTc]Tc-N4-PSMA-12 showed higher TBR than [99mTc]Tc-PSMA-I&S for blood and all evaluated tissue. In addition, a procedure suitable for routine clinical production of [99mTc]Tc-N4-PSMA-12 was established. Labeling with 553 ± 187 MBq was achieved with RCP of 98.5 ± 0.6% (n = 10). CONCLUSION High tumor accumulation and favorable clearance from blood and non-target tissue make [99mTc]Tc-N4-PSMA-12 an attractive tracer for RGS, possibly superior to currently established [99mTc]Tc-PSMA-I&S. Its GMP-production according to a method presented here and first clinical investigations with this novel radioligand is highly recommended.
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Affiliation(s)
- Jan-Philip Kunert
- Chair of Pharmaceutical Radiochemistry, Department of Chemistry, Technical University of Munich (TUM), Walther-Meißner-Str 3, 85748, Garching, Germany.
| | - Max Müller
- grid.6936.a0000000123222966Chair of Pharmaceutical Radiochemistry, Department of Chemistry, Technical University of Munich (TUM), Walther-Meißner-Str 3, 85748 Garching, Germany
| | - Thomas Günther
- grid.6936.a0000000123222966Chair of Pharmaceutical Radiochemistry, Department of Chemistry, Technical University of Munich (TUM), Walther-Meißner-Str 3, 85748 Garching, Germany
| | - León Stopper
- grid.6936.a0000000123222966Chair of Pharmaceutical Radiochemistry, Department of Chemistry, Technical University of Munich (TUM), Walther-Meißner-Str 3, 85748 Garching, Germany
| | - Nicole Urtz-Urban
- grid.6936.a0000000123222966Chair of Pharmaceutical Radiochemistry, Department of Chemistry, Technical University of Munich (TUM), Walther-Meißner-Str 3, 85748 Garching, Germany
| | - Roswitha Beck
- grid.6936.a0000000123222966Chair of Pharmaceutical Radiochemistry, Department of Chemistry, Technical University of Munich (TUM), Walther-Meißner-Str 3, 85748 Garching, Germany
| | - Hans-Jürgen Wester
- grid.6936.a0000000123222966Chair of Pharmaceutical Radiochemistry, Department of Chemistry, Technical University of Munich (TUM), Walther-Meißner-Str 3, 85748 Garching, Germany
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18
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Gafita A, Rauscher I, Weber M, Hadaschik B, Wang H, Armstrong WR, Tauber R, Grogan TR, Czernin J, Rettig MB, Herrmann K, Calais J, Weber WA, Benz MR, Fendler WP, Eiber M. Novel Framework for Treatment Response Evaluation Using PSMA PET/CT in Patients with Metastatic Castration-Resistant Prostate Cancer (RECIP 1.0): An International Multicenter Study. J Nucl Med 2022; 63:1651-1658. [PMID: 35422442 PMCID: PMC9635677 DOI: 10.2967/jnumed.121.263072] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 03/17/2022] [Indexed: 11/16/2022] Open
Abstract
Our objective was to develop version 1.0 of a novel framework for response evaluation criteria in prostate-specific membrane antigen (PSMA) PET/CT (RECIP) and a composite response classification that combines responses by prostate-specific antigen (PSA) measurements and by RECIP 1.0 (PSA + RECIP). Methods: This was an international multicenter, retrospective study. One hundred twenty-four men with metastatic castration-specific prostate cancer (mCRPC) who underwent 177Lu-PSMA therapy and received PSMA PET/CT at baseline and at an interim time point of 12 wk were included. Pairs of baseline interim PET/CT scans were interpreted by consensus among 3 masked readers for appearance of new lesions. Tumor lesions were segmented, and total PSMA-positive tumor volume (PSMA-VOL) was obtained. Appearance of new lesions and changes in PSMA-VOL were combined to develop RECIP 1.0, which included classifications of complete response (RECIP-CR: absence of any PSMA-ligand uptake on interim PET/CT), partial response (RECIP-PR: decline ≥ 30% in PSMA-VOL and no appearance of new lesions), progressive disease (RECIP-PD: increase ≥ 20% in PSMA-VOL and appearance of new lesions), and stable disease (RECIP-SD: any condition but RECIP-PR or RECIP-PD). Changes in PSA levels at 12 wk by Prostate Cancer Working Group Criteria 3 were recorded. PSA + RECIP results were defined as response (PSA decline ≥ 50% or RECIP-PR/CR) or progression (PSA increase ≥ 25% or RECIP-PD). The study's primary outcome measure was the prognostic value of RECIP 1.0 for overall survival (OS). The secondary outcome measure was the prognostic accuracy (C-index) of PSA + RECIP versus PSA responses. Results: Patients with RECIP-PD (n = 39; 8.3 mo) had a shorter OS than patients with stable disease (RECIP-SD) (n = 47; 13.1 mo; P < 0.001) or RECIP-PR (n = 38; 21.7 mo; P < 0.001). In identifying responders and progressors, PSA + RECIP had C-indices superior to those of PSA only: 0.65 versus 0.62 (P = 0.028) and 0.66 versus 0.63 (P = 0.044), respectively. Conclusion: PSMA PET/CT by RECIP 1.0 is prognostic for OS and can be used as a response biomarker to monitor early efficacy of 177Lu-PSMA in men with mCRPC. PSA + RECIP may be used as a novel composite endpoint in mCRPC clinical trial design.
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Affiliation(s)
- Andrei Gafita
- Ahmanson Translational Theranostics Division, Department of Molecular and Medical Pharmacology, UCLA, Los Angeles, California;
- Department of Nuclear Medicine, Technical University Munich, Klinikum rechts der Isar, Munich, Germany
| | - Isabel Rauscher
- Department of Nuclear Medicine, Technical University Munich, Klinikum rechts der Isar, Munich, Germany
| | - Manuel Weber
- Department of Nuclear Medicine, University of Duisburg-Essen and German Cancer Consortium-University Hospital Essen, Essen, Germany
| | - Boris Hadaschik
- Department of Urology, University of Duisburg-Essen and German Cancer Consortium-University Hospital Essen, Essen, Germany
| | - Hui Wang
- Department of Nuclear Medicine, Technical University Munich, Klinikum rechts der Isar, Munich, Germany
| | - Wesley R Armstrong
- Ahmanson Translational Theranostics Division, Department of Molecular and Medical Pharmacology, UCLA, Los Angeles, California
| | - Robert Tauber
- Department of Urology, Technical University Munich, Klinikum rechts der Isar, Munich, Germany
| | - Tristan R Grogan
- Department of Medicine Statistics Core, David Geffen School of Medicine, UCLA, Los Angeles, California; and
| | - Johannes Czernin
- Ahmanson Translational Theranostics Division, Department of Molecular and Medical Pharmacology, UCLA, Los Angeles, California
| | - Matthew B Rettig
- Department of Urology, David Geffen School of Medicine, UCLA, Los Angeles, California
| | - Ken Herrmann
- Department of Nuclear Medicine, University of Duisburg-Essen and German Cancer Consortium-University Hospital Essen, Essen, Germany
| | - Jeremie Calais
- Ahmanson Translational Theranostics Division, Department of Molecular and Medical Pharmacology, UCLA, Los Angeles, California
| | - Wolfgang A Weber
- Department of Nuclear Medicine, Technical University Munich, Klinikum rechts der Isar, Munich, Germany
| | - Matthias R Benz
- Ahmanson Translational Theranostics Division, Department of Molecular and Medical Pharmacology, UCLA, Los Angeles, California
| | - Wolfgang P Fendler
- Department of Nuclear Medicine, University of Duisburg-Essen and German Cancer Consortium-University Hospital Essen, Essen, Germany
| | - Matthias Eiber
- Department of Nuclear Medicine, Technical University Munich, Klinikum rechts der Isar, Munich, Germany
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19
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Hirata S, Mishiro K, Higashi T, Fuchigami T, Munekane M, Arano Y, Kinuya S, Ogawa K. Synthesis and evaluation of a multifunctional probe with a high affinity for prostate-specific membrane antigen (PSMA) and bone. Nucl Med Biol 2022; 114-115:34-41. [PMID: 36088875 DOI: 10.1016/j.nucmedbio.2022.08.004] [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: 07/28/2022] [Revised: 08/17/2022] [Accepted: 08/18/2022] [Indexed: 12/27/2022]
Abstract
Prostate cancer frequently metastasizes to the bone. Because patients with bone metastases suffer from skeletal-related events, the diagnosis and treatment of bone metastases in the early stage are important. In this study, to improve the sensitivity of detecting bone metastases in patients with prostate cancer, we designed, synthesized, and evaluated a multifunctional radiotracer, [67Ga]Ga-D11-PSMA-617 ([67Ga]3), with an undeca-aspartic acid as a bone-seeking moiety between [67Ga]Ga-DOTA and a prostate-specific membrane antigen (PSMA) ligand based on the lysine-urea-glutamate motif. [67Ga]3 showed a high affinity for hydroxyapatite and high uptake in PSMA-positive LNCaP cells. Moreover, in biodistribution experiments using tumor-bearing mice, [67Ga]3 exhibited high accumulation in the bone and PSMA-positive tumor although the accumulation of [67Ga]3 in the PSMA-positive tumor was lower than that of [67Ga]Ga-PSMA-617. This study provides valuable information for developing radiotheranostic probes combining multiple carriers with different mechanisms.
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Affiliation(s)
- Saki Hirata
- Graduate School of Medical Sciences, Kanazawa University, Kanazawa 920-1192, Japan
| | - Kenji Mishiro
- Institute for Frontier Science Initiative, Kanazawa University, Kanazawa 920-1192, Japan
| | - Takuma Higashi
- Graduate School of Medical Sciences, Kanazawa University, Kanazawa 920-1192, Japan
| | - Takeshi Fuchigami
- Graduate School of Medical Sciences, Kanazawa University, Kanazawa 920-1192, Japan
| | - Masayuki Munekane
- Graduate School of Medical Sciences, Kanazawa University, Kanazawa 920-1192, Japan
| | - Yasushi Arano
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan
| | - Seigo Kinuya
- Department of Nuclear Medicine, Kanazawa University Hospital, Kanazawa University, Kanazawa 920-8641, Japan
| | - Kazuma Ogawa
- Graduate School of Medical Sciences, Kanazawa University, Kanazawa 920-1192, Japan; Institute for Frontier Science Initiative, Kanazawa University, Kanazawa 920-1192, Japan.
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20
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Zha Z, Choi SR, Li L, Zhao R, Ploessl K, Yao X, Alexoff D, Zhu L, Kung HF. New PSMA-Targeting Ligands: Transformation from Diagnosis (Ga-68) to Radionuclide Therapy (Lu-177). J Med Chem 2022; 65:13001-13012. [DOI: 10.1021/acs.jmedchem.2c00852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Zhihao Zha
- Five Eleven Pharma Inc., Philadelphia, Pennsylvania 19104, United States
| | - Seok Rye Choi
- Five Eleven Pharma Inc., Philadelphia, Pennsylvania 19104, United States
| | - Linlin Li
- College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Ruiyue Zhao
- College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Karl Ploessl
- Five Eleven Pharma Inc., Philadelphia, Pennsylvania 19104, United States
| | - Xinyue Yao
- College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - David Alexoff
- Five Eleven Pharma Inc., Philadelphia, Pennsylvania 19104, United States
| | - Lin Zhu
- College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Hank F. Kung
- Five Eleven Pharma Inc., Philadelphia, Pennsylvania 19104, United States
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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21
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Günther T, Deiser S, Felber V, Beck R, Wester HJ. Substitution of l-Tryptophan by α-Methyl-l-Tryptophan in 177Lu-RM2 Results in 177Lu-AMTG, a High-Affinity Gastrin-Releasing Peptide Receptor Ligand with Improved In Vivo Stability. J Nucl Med 2022; 63:1364-1370. [PMID: 35027371 PMCID: PMC9454457 DOI: 10.2967/jnumed.121.263323] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 12/28/2021] [Indexed: 01/26/2023] Open
Abstract
Theranostic applications targeting the gastrin-releasing peptide receptor (GRPR) have shown promising results. When compared with other peptide ligands for radioligand therapy, the most often used GRPR ligand, DOTA-Pip5-d-Phe6-Gln7-Trp8-Ala9-Val10-Gly11-His12-Sta13-Leu14-NH2 (RM2), may be clinically impacted by limited metabolic stability. With the aim of improving the metabolic stability of RM2, we investigated whether the metabolically unstable Gln7-Trp8 bond within the pharmacophore of RM2 can be stabilized via substitution of l-Trp8 by α-methyl-l-tryptophan (α-Me-l-Trp) and whether the corresponding DOTAGA analog might also be advantageous. A comparative preclinical evaluation of 177Lu-α-Me-l-Trp8-RM2 (177Lu-AMTG) and its DOTAGA counterpart (177Lu-AMTG2) was performed using 177Lu-RM2 and 177Lu-NeoBOMB1 as reference compounds. Methods: Peptides were synthesized by solid-phase peptide synthesis and labeled with 177Lu. Lipophilicity was determined at pH 7.4 (logD 7.4). Receptor-mediated internalization was investigated on PC-3 cells (37°C, 60 min), whereas GRPR affinity (half-maximal inhibitory concentration) was determined on both PC-3 and T-47D cells. Stability toward peptidases was examined in vitro (human plasma, 37°C, 72 ± 2 h) and in vivo (murine plasma, 30 min after injection). Biodistribution studies were performed at 24 h after injection, and small-animal SPECT/CT was performed on PC-3 tumor-bearing mice at 1, 4, 8, 24, and 28 h after injection. Results: Solid-phase peptide synthesis yielded 9%-15% purified labeling precursors. 177Lu labeling proceeded quantitatively. Compared with 177Lu-RM2, 177Lu-AMTG showed slightly improved GRPR affinity, a similar low internalization rate, slightly increased lipophilicity, and considerably improved stability in vitro and in vivo. In vivo, 177Lu-AMTG exhibited the highest tumor retention (11.45 ± 0.43 percentage injected dose/g) and tumor-to-blood ratio (2,702 ± 321) at 24 h after injection, as well as a favorable biodistribution profile. As demonstrated by small-animal SPECT/CT imaging, 177Lu-AMTG also revealed a less rapid clearance from tumor tissue. Compared with 177Lu-AMTG, 177Lu-AMTG2 did not show any further benefits. Conclusion: The results of this study, particularly the superior metabolic stability of 177Lu-AMTG, strongly recommend a clinical evaluation of this novel GRPR-targeted ligand to investigate its potential for radioligand therapy of GRPR-expressing malignancies.
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Affiliation(s)
- Thomas Günther
- Chair of Pharmaceutical Radiochemistry, Technical University of Munich, Garching, Germany
| | - Sandra Deiser
- Chair of Pharmaceutical Radiochemistry, Technical University of Munich, Garching, Germany
| | - Veronika Felber
- Chair of Pharmaceutical Radiochemistry, Technical University of Munich, Garching, Germany
| | - Roswitha Beck
- Chair of Pharmaceutical Radiochemistry, Technical University of Munich, Garching, Germany
| | - Hans-Jürgen Wester
- Chair of Pharmaceutical Radiochemistry, Technical University of Munich, Garching, Germany
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22
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Rosar F, Hügle MJ, Ries M, Bartholomä M, Maus S, Fries P, Khreish F, Ezziddin S. Benefit of including CT urography in [68Ga]PSMA-11 PET/CT with low-dose CT: first results from a larger prostate cancer cohort analysis. THE QUARTERLY JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING : OFFICIAL PUBLICATION OF THE ITALIAN ASSOCIATION OF NUCLEAR MEDICINE (AIMN) [AND] THE INTERNATIONAL ASSOCIATION OF RADIOPHARMACOLOGY (IAR), [AND] SECTION OF THE SOCIETY OF... 2022; 66:280-289. [PMID: 31992688 DOI: 10.23736/s1824-4785.20.03224-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
BACKGROUND Accuracy of [68Ga]PSMA-11 PET/CT may be hampered by ureter accumulation, mimicking lymph node metastases depending on localization and configuration. The benefit of CT urography for differentiation of lymph node metastasis from urinary tract activity was evaluated in a "PET/CT with low-dose CT" setting. METHODS Retrospective analysis of PET/CT for primary staging, biochemical recurrence or local treatment planning in patients with prostate cancer. For CT urography (CTU), iodinated contrast agent was administered 10 minutes prior to image acquisition. All potential pathologic (peri)ureteral tracer uptake was assigned to excretory ureteral accumulation or pathological lesion. To assess additional provided benefit of CTU all foci were rated with an introduced scoring system (ranging from 0 pts: CTU not needed; up to 3 pts: no differentiation possible without CTU). Success of ureter contrasting was assessed by measurement of Hounsfield units. Besides benefit for reading urography-enhanced PET/CT, the possible impact on subsequent patient treatment was evaluated. RESULTS A number of N.=247 patients were included in this study. By CT urography, it was possible to identify each ureter on low-dose CT, with its major part contrasted. In 120/247 (48.6%) patients, urography increased the diagnostic confidence while providing substantial support for interpretation in 60 (24.3%) cases. In 42 (17.0%) patients, urography was clinically relevant (up-/downstaging) with potential impact on subsequent patient care. In 30 of these 42 cases (12.1% of all), discrepant treatment would have resulted from a misdiagnosed tracer accumulation without urography. CONCLUSIONS CT urography benefits the interpretation of [68Ga]-PSMA-11 PET/CT with low-dose CT and leads to discrepant patient treatment in a small but significant subset of patients (12% in our cohort). The implementation of CT urography into standard protocols of [68Ga]PSMA-11 PET/CT with low-dose CT is recommended.
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Affiliation(s)
- Florian Rosar
- Department of Nuclear Medicine, Saarland University Medical Center, Homburg, Germany -
| | - Martin J Hügle
- Department of Nuclear Medicine, Saarland University Medical Center, Homburg, Germany
| | - Martin Ries
- Department of Nuclear Medicine, Saarland University Medical Center, Homburg, Germany
| | - Mark Bartholomä
- Department of Nuclear Medicine, Saarland University Medical Center, Homburg, Germany
| | - Stephan Maus
- Department of Nuclear Medicine, Saarland University Medical Center, Homburg, Germany
| | - Peter Fries
- Clinic of Diagnostic and Interventional Radiology, Saarland University Medical Center, Homburg, Germany
| | - Fadi Khreish
- Department of Nuclear Medicine, Saarland University Medical Center, Homburg, Germany
| | - Samer Ezziddin
- Department of Nuclear Medicine, Saarland University Medical Center, Homburg, Germany
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23
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Langbein T, Kulkarni HR, Schuchardt C, Mueller D, Volk GF, Baum RP. Salivary Gland Toxicity of PSMA-Targeted Radioligand Therapy with 177Lu-PSMA and Combined 225Ac- and 177Lu-Labeled PSMA Ligands (TANDEM-PRLT) in Advanced Prostate Cancer: A Single-Center Systematic Investigation. Diagnostics (Basel) 2022; 12:diagnostics12081926. [PMID: 36010276 PMCID: PMC9406477 DOI: 10.3390/diagnostics12081926] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 08/06/2022] [Accepted: 08/08/2022] [Indexed: 12/24/2022] Open
Abstract
Purpose: PSMA-targeted radioligand therapy (PRLT) is a promising treatment option for patients with metastatic castration-resistant prostate cancer (mCRPC). However, a high uptake of the radiopharmaceutical in the salivary glands (SG) can lead to xerostomia and becomes dose-limiting for 225Ac-PSMA-617. This study investigated the sialotoxicity of 177Lu-PSMA-I&T/-617 monotherapy and co-administered 225Ac-PSMA-617 and 177Lu-PSMA-617 (Tandem-PPRLT). Methods: Three patient cohorts, that had undergone 177Lu-PSMA-I&T/-617 monotherapy or Tandem-PRLT, were retrospectively analyzed. In a short-term cohort (91 patients), a xerostomia assessment (CTCAE v.5.0), a standardized questionnaire (sXI), salivary gland scintigraphy (SGS), and SG SUVmax and the metabolic volume (MV) on 68Ga-PSMA-11-PET/CT were obtained before and after two cycles of 177Lu-PSMA-I&T/-617. In a long-term cohort, 40 patients were similarly examined. In a Tandem cohort, the same protocol was applied to 18 patients after one cycle of Tandem-PRLT. Results: Grade 1 xerostomia in the short-term follow-up was observed in 22 (24.2%) patients with a worsening of sXI from 7 to 8 at (p < 0.05). In the long-term cohort, xerostomia grades 1 to 2 occurred in 16 (40%) patients. SGS showed no significant changes, but there was a decline of the MV of all SGs. After Tandem-PRLT, 12/18 (66.7%) patients reported xerostomia grades 1 to 2, and the sXI significantly worsened from 9.5 to 14.0 (p = 0.005), with a significant reduction in the excretion fraction (EF) and MV of all SGs. Conclusion: 177Lu-PSMA-I&T/-617 causes only minor SG toxicity, while one cycle of Tandem-PRLT results in a significant SG impairment. This standardized protocol may help to objectify and quantify SG dysfunction.
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Affiliation(s)
- Thomas Langbein
- Theranostics Center for Molecular Radiotherapy and Molecular Imaging, Zentralklinik Bad Berka, 99438 Bad Berka, Germany
- Department of Nuclear Medicine, Technical University of Munich, Klinikum Rechts der Isar, 81675 Munich, Germany
- Correspondence: ; Tel.: +49-8941402972; Fax: +49-8941404950
| | - Harshad R. Kulkarni
- Theranostics Center for Molecular Radiotherapy and Molecular Imaging, Zentralklinik Bad Berka, 99438 Bad Berka, Germany
- BAMF Health, Grand Rapids, MI 49503, USA
| | - Christiane Schuchardt
- Theranostics Center for Molecular Radiotherapy and Molecular Imaging, Zentralklinik Bad Berka, 99438 Bad Berka, Germany
| | - Dirk Mueller
- Theranostics Center for Molecular Radiotherapy and Molecular Imaging, Zentralklinik Bad Berka, 99438 Bad Berka, Germany
- Department of Nuclear Medicine, University Hospital Ulm, 89081 Ulm, Germany
| | - Gerd Fabian Volk
- Department of Otorhinolaryngology, Facial-Nerve-Center Jena, Center for Rare Diseases Jena, Jena University Hospital, 07743 Jena, Germany
| | - Richard P. Baum
- Theranostics Center for Molecular Radiotherapy and Molecular Imaging, Zentralklinik Bad Berka, 99438 Bad Berka, Germany
- CURANOSTICUM Wiesbaden-Frankfurt, Center for Advanced Radiomolecular Precision Oncology, 65191 Wiesbaden, Germany
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24
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Kwon D, Zhang Z, Zeisler J, Kuo HT, Lin KS, Benard F. Reducing the Kidney Uptake of High Contrast CXCR4 PET Imaging Agents via Linker Modifications. Pharmaceutics 2022; 14:pharmaceutics14071502. [PMID: 35890397 PMCID: PMC9316317 DOI: 10.3390/pharmaceutics14071502] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 07/02/2022] [Accepted: 07/07/2022] [Indexed: 01/27/2023] Open
Abstract
Purpose: The C-X-C chemokine receptor 4 (CXCR4) is highly expressed in many subtypes of cancers, notably in several kidney-based malignancies. We synthesized, labeled, and assessed a series of radiotracers based on a previous high contrast PET imaging radiopharmaceutical [68Ga]Ga-BL02, with modifications to its linker and metal chelator, in order to improve its tumor-to-kidney contrast ratio. Methods: Based on the design of BL02, a piperidine-based cationic linker (BL06) and several anionic linkers (tri-Aad (BL17); tri-D-Glu (BL20); tri-Asp (BL25); and tri-cysteic acid (BL31)) were substituted for the triglutamate linker. Additionally, the DOTA chelator was swapped for a DOTAGA chelator (BL30). Each radiotracer was labeled with 68Ga and evaluated in CXCR4-expressing Daudi xenograft mice with biodistribution and/or PET imaging studies. Results: Of all the evaluated radiotracers, [68Ga]Ga-BL31 showed the most promising biodistribution profile, with a lower kidney uptake compared to [68Ga]Ga-BL02, while retaining the high imaging contrast capabilities of [68Ga]Ga-BL02. [68Ga]Ga-BL31 also compared favorably to [68Ga]Ga-Pentixafor, with superior imaging contrast in all non-target organs. The other anionic linker-based radiotracers showed either equivocal or worse contrast ratios compared to [68Ga]Ga-BL02; however, [68Ga]Ga-BL25 also showed lower kidney uptake, as compared to that of [68Ga]Ga-BL02. Meanwhile, [68Ga]Ga-BL06 had high non-target organ uptake and relatively lower tumor uptake, while [68Ga]Ga-BL30 showed significantly increased kidney uptake and similar tumor uptake values. Conclusions: [68Ga]Ga-BL31 is an optimized CXCR4-targeting radiopharmaceutical with lower kidney retention that has clinical potential for PET imaging and radioligand therapy.
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Affiliation(s)
- Daniel Kwon
- Department of Molecular Oncology, BC Cancer, Vancouver, BC V5Z 1L3, Canada; (D.K.); (Z.Z.); (J.Z.); (H.-T.K.); (K.-S.L.)
| | - Zhengxing Zhang
- Department of Molecular Oncology, BC Cancer, Vancouver, BC V5Z 1L3, Canada; (D.K.); (Z.Z.); (J.Z.); (H.-T.K.); (K.-S.L.)
| | - Jutta Zeisler
- Department of Molecular Oncology, BC Cancer, Vancouver, BC V5Z 1L3, Canada; (D.K.); (Z.Z.); (J.Z.); (H.-T.K.); (K.-S.L.)
| | - Hsiou-Ting Kuo
- Department of Molecular Oncology, BC Cancer, Vancouver, BC V5Z 1L3, Canada; (D.K.); (Z.Z.); (J.Z.); (H.-T.K.); (K.-S.L.)
| | - Kuo-Shyan Lin
- Department of Molecular Oncology, BC Cancer, Vancouver, BC V5Z 1L3, Canada; (D.K.); (Z.Z.); (J.Z.); (H.-T.K.); (K.-S.L.)
- Department of Radiology, University of British Columbia, Vancouver, BC V5Z 1M9, Canada
| | - Francois Benard
- Department of Molecular Oncology, BC Cancer, Vancouver, BC V5Z 1L3, Canada; (D.K.); (Z.Z.); (J.Z.); (H.-T.K.); (K.-S.L.)
- Department of Radiology, University of British Columbia, Vancouver, BC V5Z 1M9, Canada
- Correspondence: ; Tel.: +1-604-675-8206
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Di Iorio V, Boschi S, Cuni C, Monti M, Severi S, Paganelli G, Masini C. Production and Quality Control of [ 177Lu]Lu-PSMA-I&T: Development of an Investigational Medicinal Product Dossier for Clinical Trials. Molecules 2022; 27:molecules27134143. [PMID: 35807385 PMCID: PMC9268543 DOI: 10.3390/molecules27134143] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 06/22/2022] [Accepted: 06/24/2022] [Indexed: 11/16/2022] Open
Abstract
Since prostate cancer is the most commonly diagnosed malignancy in men, the theranostic approach has become very attractive since the discovery of urea-based PSMA inhibitors. Different molecules have been synthesized starting from the Glu-urea-Lys scaffold as the pharmacophore and then optimizing the linker and the chelate to improve functional characteristics. This article aimed to highlight the quality aspects, which could have an impact on clinical practice, describing the development of an Investigational Medicinal Product Dossier (IMPD) for clinical trials with [177Lu]Lu-PSMA-I&T in prostate cancer and other solid tumors expressing PSMA. The results highlighted some important quality issues of the final preparation: radiolabeling of PSMA-I&T with lutetium-177 needs a considerably longer time compared with the radiolabeling of the well-known [177Lu]Lu-PSMA-617. When the final product was formulated in saline, the stability of [177Lu]Lu-PSMA-I&T was reduced by radiolysis, showing a decrease in radiochemical purity (<95% in 24 h). Different formulations of the final product with increasing concentrations of ascorbic acid have been tested to counteract radiolysis and extend stability. A solution of 20 mg/mL of ascorbic acid in saline prevents radiolysis and ensures stability over 30 h.
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Affiliation(s)
- Valentina Di Iorio
- IRCCS Istituto Romagnolo per lo Studio dei Tumori “Dino Amadori” IRST, 47014 Meldola, Italy; (C.C.); (M.M.); (S.S.); (G.P.); (C.M.)
- Correspondence: ; Tel.: +39-0543739930
| | - Stefano Boschi
- Department of Pharmacy and Biotechnologies, University of Bologna, 47921 Rimini, Italy;
| | - Cristina Cuni
- IRCCS Istituto Romagnolo per lo Studio dei Tumori “Dino Amadori” IRST, 47014 Meldola, Italy; (C.C.); (M.M.); (S.S.); (G.P.); (C.M.)
| | - Manuela Monti
- IRCCS Istituto Romagnolo per lo Studio dei Tumori “Dino Amadori” IRST, 47014 Meldola, Italy; (C.C.); (M.M.); (S.S.); (G.P.); (C.M.)
| | - Stefano Severi
- IRCCS Istituto Romagnolo per lo Studio dei Tumori “Dino Amadori” IRST, 47014 Meldola, Italy; (C.C.); (M.M.); (S.S.); (G.P.); (C.M.)
| | - Giovanni Paganelli
- IRCCS Istituto Romagnolo per lo Studio dei Tumori “Dino Amadori” IRST, 47014 Meldola, Italy; (C.C.); (M.M.); (S.S.); (G.P.); (C.M.)
| | - Carla Masini
- IRCCS Istituto Romagnolo per lo Studio dei Tumori “Dino Amadori” IRST, 47014 Meldola, Italy; (C.C.); (M.M.); (S.S.); (G.P.); (C.M.)
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Schilham MG, Küsters-Vandevelde H, Somford DM, Rijpkema M, Gotthardt M. How Image-Guided Pathology Can Improve the Detection of Lymph Node Metastases in Prostate Cancer. Clin Nucl Med 2022; 47:559-561. [PMID: 35439175 PMCID: PMC9071021 DOI: 10.1097/rlu.0000000000004158] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 01/20/2022] [Indexed: 11/26/2022]
Abstract
ABSTRACT Detection of lymph node (LN) metastases in prostate cancer (PCa) is pivotal for accurate staging and determining treatment options. To date, the reference standard for nodal staging is histopathological examination of all harvested surgical specimens from extended pelvic LN dissections. However, this is a labor-intensive process, and small metastatic foci can be missed due to sampling effects. With current research expanding toward using radiolabeled prostate-specific membrane antigen ligands for image-guided surgery, new opportunities arise for image-guided pathological assessment of surgical specimens. Here, we illustrate how molecular imaging can complement histopathology and improve accurate detection of LN metastases.
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Affiliation(s)
- Melline G.M. Schilham
- From the Department of Medical Imaging, Nuclear Medicine
- Department of Urology, Radboud University Medical Centre
- Prosper Prostate Cancer Clinics, Nijmegen, the Netherlands
| | | | - Diederik M. Somford
- Urology, Canisius Wilhelmina Hospital
- Prosper Prostate Cancer Clinics, Nijmegen, the Netherlands
| | - M. Rijpkema
- From the Department of Medical Imaging, Nuclear Medicine
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27
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EANM dosimetry committee recommendations for dosimetry of 177Lu-labelled somatostatin-receptor- and PSMA-targeting ligands. Eur J Nucl Med Mol Imaging 2022; 49:1778-1809. [PMID: 35284969 PMCID: PMC9015994 DOI: 10.1007/s00259-022-05727-7] [Citation(s) in RCA: 79] [Impact Index Per Article: 39.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 02/13/2022] [Indexed: 12/25/2022]
Abstract
The purpose of the EANM Dosimetry Committee is to provide recommendations and guidance to scientists and clinicians on patient-specific dosimetry. Radiopharmaceuticals labelled with lutetium-177 (177Lu) are increasingly used for therapeutic applications, in particular for the treatment of metastatic neuroendocrine tumours using ligands for somatostatin receptors and prostate adenocarcinoma with small-molecule PSMA-targeting ligands. This paper provides an overview of reported dosimetry data for these therapies and summarises current knowledge about radiation-induced side effects on normal tissues and dose-effect relationships for tumours. Dosimetry methods and data are summarised for kidneys, bone marrow, salivary glands, lacrimal glands, pituitary glands, tumours, and the skin in case of radiopharmaceutical extravasation. Where applicable, taking into account the present status of the field and recent evidence in the literature, guidance is provided. The purpose of these recommendations is to encourage the practice of patient-specific dosimetry in therapy with 177Lu-labelled compounds. The proposed methods should be within the scope of centres offering therapy with 177Lu-labelled ligands for somatostatin receptors or small-molecule PSMA.
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PSMA-Targeting Imaging and Theranostic Agents-Current Status and Future Perspective. Int J Mol Sci 2022; 23:ijms23031158. [PMID: 35163083 PMCID: PMC8835702 DOI: 10.3390/ijms23031158] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 01/15/2022] [Accepted: 01/17/2022] [Indexed: 12/13/2022] Open
Abstract
In the past two decades, extensive efforts have been made to develop agents targeting prostate-specific membrane antigen (PSMA) for prostate cancer imaging and therapy. To date, represented by two recent approvals of [68Ga]Ga-PSMA-11 and [18F]F-DCFPyL by the United States Food and Drug Administration (US-FDA) for positron emission tomography (PET) imaging to identify suspected metastases or recurrence in patients with prostate cancer, PSMA-targeting imaging and theranostic agents derived from small molecule PSMA inhibitors have advanced to clinical practice and trials of prostate cancer. The focus of current development of new PSMA-targeting agents has thus shifted to the improvement of in vivo pharmacokinetics and higher specific binding affinity with the aims to further increase the detection sensitivity and specificity and minimize the toxicity to non-target tissues, particularly the kidneys. The main strategies involve systematic chemical modifications of the linkage between the targeting moiety and imaging/therapy payloads. In addition to a summary of the development history of PSMA-targeting agents, this review provides an overview of current advances and future promise of PSMA-targeted imaging and theranostics with focuses on the structural determinants of the chemical modification towards the next generation of PSMA-targeting agents.
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29
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Ong JS, Hofman MS. PET imaging of prostate cancer. Nucl Med Mol Imaging 2022. [DOI: 10.1016/b978-0-12-822960-6.00111-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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30
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Gühne F, Radke S, Winkens T, Kühnel C, Greiser J, Seifert P, Drescher R, Freesmeyer M. Differences in Distribution and Detection Rate of the [ 68Ga]Ga-PSMA Ligands PSMA-617, -I&T and -11-Inter-Individual Comparison in Patients with Biochemical Relapse of Prostate Cancer. Pharmaceuticals (Basel) 2021; 15:ph15010009. [PMID: 35056066 PMCID: PMC8779232 DOI: 10.3390/ph15010009] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 12/20/2021] [Accepted: 12/21/2021] [Indexed: 12/04/2022] Open
Abstract
The biochemical relapse of prostate cancer is diagnostically challenging but of high clinical impact for subsequent patient treatment. PET/CT with radiolabeled PSMA ligands outperforms conventional diagnostic methods in the detection of tumor recurrence. Several radiopharmaceuticals were and are available for use. The aim of this study was to investigate whether the routinely applied [68Ga]Ga-PSMA ligands PSMA-617, -I&T and -11 (HBED-CC) differ in physiological and pathological distribution, or in tumor detection rate. A retrospective evaluation of 190 patients (39 patients received PSMA-617, 68 patients PSMA-I&T and 83 patients PSMA-11) showed significant differences in tracer accumulation within all organs examined. The low retention within the compartments blood pool, bone and muscle tissue is a theoretical advantage of PSMA-11. Evaluation of tumor lesion uptake and detection rate did not reveal superiority of one of the three radiopharmaceuticals, neither in the whole population, nor in particularly challenging subgroups like patients with very low PSA levels. We conclude that all three [68Ga]Ga-PSMA ligands are equally feasible in this clinically important scenario, and may replace each other in case of unavailability or production restrictions.
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31
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Rogowski P, Trapp C, von Bestenbostel R, Eze C, Ganswindt U, Li M, Unterrainer M, Zacherl MJ, Ilhan H, Beyer L, Kretschmer A, Bartenstein P, Stief C, Belka C, Schmidt-Hegemann NS. Outcome after PSMA-PET/CT-based salvage radiotherapy for nodal recurrence after radical prostatectomy. Eur J Nucl Med Mol Imaging 2021; 49:1417-1428. [PMID: 34628521 PMCID: PMC8921036 DOI: 10.1007/s00259-021-05557-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 09/05/2021] [Indexed: 11/27/2022]
Abstract
Purpose Nodal recurrent prostate cancer (PCa) represents a common state of disease, amenable to local therapy. PSMA-PET/CT detects PCa recurrence at low PSA levels. The aim of this study was to evaluate the outcome of PSMA-PET/CT-based salvage radiotherapy (sRT) for lymph node (LN) recurrence. Methods A total of 100 consecutive patients treated with PSMA-PET/CT-based salvage elective nodal radiotherapy (sENRT) for LN recurrence were retrospectively examined. Patients underwent PSMA-PET/CT scan due to biochemical persistence (bcP, 76%) or biochemical recurrence (bcR, 24%) after radical prostatectomy (RP). Biochemical recurrence-free survival (BRFS) defined as PSA < post-RT nadir + 0.2 ng/ml and distant metastasis-free survival (DMFS) were calculated using the Kaplan–Meier method and uni- and multivariate analysis was performed. Results Median follow-up was 37 months. Median PSA at PSMA-PET/CT was 1.7 ng/ml (range 0.1–40.1) in patients with bcP and 1.4 ng/ml (range 0.3–5.1) in patients with bcR. PSMA-PET/CT detected 1, 2, and 3 or more LN metastases in 35%, 23%, and 42%, respectively. Eighty-three percent had only pelvic, 2% had only paraaortic, and 15% had pelvic and paraaortic LN metastases. Cumulatively, a total dose converted to EQD21.5 Gy of 66 Gy (60–70 Gy) was delivered to the prostatic fossa, 70 Gy (66–72 Gy) to the local recurrence, if present, 65.1 Gy (56–66 Gy) to PET-positive lymph nodes, and 47.5 Gy (42.4–50.9 Gy) to the lymphatic pathways. Concomitant androgen deprivation therapy (ADT) was administered in 83% of patients. One-, 2-, and 3-year BRFS was 80.7%, 71.6%, and 65.8%, respectively. One-, 2-, and 3-year DMFS was 91.6%, 79.1%, and 66.4%, respectively. In multivariate analysis, concomitant ADT, longer ADT duration (≥ 12 vs. < 12 months) and LN localization (pelvic vs. paraaortic) were associated with improved BRFS and concomitant ADT and lower PSA value before sRT (< 1 vs. > 1 ng/ml) with improved DMFS, respectively. No such association was seen for the number of affected lymph nodes. Conclusions Overall, the present analysis shows that the so far, unmatched sensitivity and specificity of PSMA-PET/CT translates in comparably high BRFS and DMFS after PSMA-PET/CT-based sENRT for patients with PCa LN recurrence. Concomitant ADT, duration of ADT, PSA value before sRT, and localization of LN metastases were significant factors for improved outcome.
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Affiliation(s)
- Paul Rogowski
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistr. 15, 81377, Munich, Germany.
| | - Christian Trapp
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistr. 15, 81377, Munich, Germany
| | - Rieke von Bestenbostel
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistr. 15, 81377, Munich, Germany
| | - Chukwuka Eze
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistr. 15, 81377, Munich, Germany
| | - Ute Ganswindt
- Department of Radiation Oncology, University Hospital, Medical University Innsbruck, Innsbruck, Austria
| | - Minglun Li
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistr. 15, 81377, Munich, Germany
| | - Marcus Unterrainer
- Department of Radiology, University Hospital, LMU Munich, Munich, Germany.,Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Mathias J Zacherl
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Harun Ilhan
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Leonie Beyer
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | | | - Peter Bartenstein
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Christian Stief
- Department of Urology, University Hospital, LMU Munich, Munich, Germany
| | - Claus Belka
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistr. 15, 81377, Munich, Germany.,German Cancer Consortium (DKTK), Munich, Germany
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Notni J. PSMA-Targeted Therapeutics: A Tale About Law and Economics. J Nucl Med 2021; 62:1482. [PMID: 33789934 DOI: 10.2967/jnumed.121.262308] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 03/13/2021] [Accepted: 03/16/2021] [Indexed: 11/16/2022] Open
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Stolzenbach LF, Löcherbach F, Wargenau K, Pose R, Steuber T, Tian Z, Budäus L, Tilki D, Graefen M, Köhler D, Karakiewicz PI, Sauer M, Apostolova II, Maurer T, Berliner C. Clinical impact of whole-body 68Ga-PSMA I&T PET/CT: lesion frequency and added benefit in lower extremities. Nuklearmedizin 2021; 60:417-424. [PMID: 34416785 DOI: 10.1055/a-1542-6064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
AIM Few small-scaled studies performed systematic analysis of the benefits of extending prostate specific membrane antigen positron-emission tomography/ computed tomography (68Ga-PSMA I&T PET/CT) to the lower extremities in prostate cancer (PCa) patients. We hypothesized that 68Ga-PSMA I&T PET/CT positive lesions are rare in lower extremities of prostate cancer (PCa) patients, the clinical implication is negligible and may therefore be omitted. METHODS We retrospectively analyzed 1,068 PCa patients who received 68Ga-PSMA I&T PET/CT in a single institution (2016-2018). Of those, 285 (26.7%) were newly diagnosed, 529 (49.5%) had biochemical recurrence (BCR) and 254 (23.8%) were castration-resistant prostate cancer (CRPC) patients. RESULTS Of 1,068 68Ga-PSMA I&T PET/CTs, positive lesions in the lower extremities were identified in 6.9% patients (n=74). Positive lesions in the lower extremities were most common in CRPC patients (19.7%; n=50), followed by newly diagnosed (3.2%; n=9) and BCR (2.8%; n=15) PCa patients. Only 3 patients presented with exclusive lesions in the lower extremities, respectively 0.8% (n=2) in CRPC and 0.4% (n=1) in newly diagnosed PCa. Both CRPC (94.1%, n=47) and BCR (80.0%, n=12) patients with PSMA-positive lesions predominantly received systemic therapy. CONCLUSION Identification of lower extremities lesions with PSMA PET/CT is uncommon and exclusive lesions are rare. PSMA PET/CT findings of the lower extremities did not change therapy management. Thus, scanning of the lower extremities can be omitted in standard protocols.
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Affiliation(s)
| | - Florian Löcherbach
- Department of Urology, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | - Katharina Wargenau
- Department of Urology, Universitätsklinikum Schleswig-Holstein - Campus Lübeck, Lubeck, Germany
| | - Randi Pose
- Martini-Klinik, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | - Thomas Steuber
- Martini-Klinik, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | - Zhe Tian
- École de santé publique - Département de santé environnementale et santé au travail, Université de Montréal, Montreal, Canada
| | - Lars Budäus
- Martini-Klinik, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | - Derya Tilki
- Martini-Klinik, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany.,Department of Urology, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | - Markus Graefen
- Martini-Klinik, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | - Daniel Köhler
- Department for Diagnostic and Interventional Radiology and Nuclear Medicine, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | - Pierre I Karakiewicz
- École de santé publique - Département de santé environnementale et santé au travail, Université de Montréal, Montreal, Canada
| | - Markus Sauer
- Department for Diagnostic and Interventional Radiology and Nuclear Medicine, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | | | - Tobias Maurer
- Martini-Klinik, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany.,Department of Urology, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | - Christoph Berliner
- Department for Diagnostic and Interventional Radiology and Nuclear Medicine, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany.,Department for Nuclear Medicine, Universitätsklinikum Essen, Essen, Germany
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Chakraborty A, Mitra A, Tawate M, Sahoo S, Lad S, Rakshit S, Gaikwad S, Basu S, Shimpi H, Banerjee S. Therapeutic Multidose Preparation of a Ready-to-Use 177Lu-PSMA-617 Using Carrier Added Lutetium-177 in a Hospital Radiopharmacy and Its Clinical Efficacy. Cancer Biother Radiopharm 2021; 36:682-692. [PMID: 34402687 DOI: 10.1089/cbr.2020.4261] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Introduction: [177Lu]Lu-prostate-specific membrane antigen (PSMA)-617 has emerged as a promising radiopharmaceutical for targeting PSMA in metastatic castrate-resistant prostate carcinoma (mCRPC). We have optimized the radiolabeling protocol for a multidose formulation (27-28.8 GBq equivalent to 6-7 patient-doses) of [177Lu]Lu-PSMA-617 using [177Lu]Lu3+ produced via 176Lu(n,γ)177Lu route with moderate specific activity (0.66-0.81 GBq/μg). Methods: [177Lu]Lu-PSMA-617 was synthesized using moderate specific activity [177Lu]LuCl3 (0.74 GBq/μg) with PSMA-617 having metal-to-ligand molar ratio ∼1: 2.5 in CH3COONH4 buffer (0.1 M) containing gentisic acid at pH 4.0-4.5. Human prostate carcinoma cell line LNCaP cell (high PSMA expression) was used for in vitro cell-binding studies and generating tumor xenograft models in nude mice for tissue biodistribution studies. Several batches of the present formulation have been clinically administered in mCRPC patients (single patient dose: 4.44-5.55 GBq per cycle). Results: In this study we report a consistent and reproducible protocol for multidose formulations of [177Lu]Lu-PSMA-617 for adopting in a hospital radiopharmacy setting. Although the radiochemical yield of [177Lu]Lu-PSMA-617 was found to be 97.30% ± 1.03%, the radiochemical purity was 98.24% ± 0.50% (n = 19). In vitro and serum stability of [177Lu]Lu-PSMA-617 was retained up to 72 and 120 h after radiolabeling and upon storage at -20°C with a radioactive concentration between 0.37 and 0.74 GBq/mL upon using stabilizer concentration as low as 43-48 μg/mCi. Preclinical cell-binding studies of [177Lu]Lu-PSMA-617 revealed specific binding with LNCaP cells of 17.4% ± 2.4%. The uptake in LnCaP xenografted tumor (nude mice) was 7.5 ± 2.6% ID/g for ∼1.5-2.0 cm3 tumor volume at 24-h post-injection. Post-therapy (24 h) SPECT image of mCRPC patients with prior orchidectomy and various hormone therapy showed specific localization of [177Lu]Lu-PSMA-617 in the tumor region. Conclusions: Formulation of a ready-to-use multidose formulation of [177Lu]Lu-PSMA-617 was successfully achieved and the procedure was optimized for routine preparation at a hospital radiopharmacy set-up. High degree of localization of [177Lu]Lu-PSMA-617 in post-therapy SPECT scan and the post-therapeutic response confirms its therapeutic efficacy. Clinical Trials.gov ID: RPC/51/Minutes/Final dated 16th October, 2019.
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Affiliation(s)
- Avik Chakraborty
- Radiation Medicine Centre, Bhabha Atomic Research Centre, Mumbai, India.,Department of Atomic Energy, Homi Bhabha National Institute, Mumbai, India
| | - Arpit Mitra
- Medical Cyclotron Facility, Radiation Medicine Centre, Board of Radiation and Isotope Technology, Mumbai, India
| | - Megha Tawate
- Radiation Medicine Centre, Bhabha Atomic Research Centre, Mumbai, India
| | - Sudip Sahoo
- Radiation Medicine Centre, Bhabha Atomic Research Centre, Mumbai, India
| | - Sangita Lad
- Radiation Medicine Centre, Bhabha Atomic Research Centre, Mumbai, India
| | - Sutapa Rakshit
- Radiation Medicine Centre, Bhabha Atomic Research Centre, Mumbai, India
| | - Sujay Gaikwad
- Radiation Medicine Centre, Bhabha Atomic Research Centre, Mumbai, India.,Department of Atomic Energy, Homi Bhabha National Institute, Mumbai, India
| | - Sandip Basu
- Radiation Medicine Centre, Bhabha Atomic Research Centre, Mumbai, India.,Department of Atomic Energy, Homi Bhabha National Institute, Mumbai, India
| | - Hemant Shimpi
- Radiation Medicine Centre, Bhabha Atomic Research Centre, Mumbai, India
| | - Sharmila Banerjee
- Radiation Medicine Centre, Bhabha Atomic Research Centre, Mumbai, India.,Department of Atomic Energy, Homi Bhabha National Institute, Mumbai, India.,Medical Cyclotron Facility, Radiation Medicine Centre, Board of Radiation and Isotope Technology, Mumbai, India
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El Fakiri M, Geis NM, Ayada N, Eder M, Eder AC. PSMA-Targeting Radiopharmaceuticals for Prostate Cancer Therapy: Recent Developments and Future Perspectives. Cancers (Basel) 2021; 13:cancers13163967. [PMID: 34439121 PMCID: PMC8393521 DOI: 10.3390/cancers13163967] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 07/22/2021] [Accepted: 07/28/2021] [Indexed: 12/12/2022] Open
Abstract
Simple Summary One of the most frequently diagnosed cancer in men is adenocarcinoma of the prostate. Once the disease is metastatic, only very limited treatment options are available, resulting in a very short median survival time of 13 months; however, this reality is gradually changing due to the discovery of prostate-specific membrane antigen (PSMA), a protein that is present in cancerous prostate tissue. Researchers have developed pharmaceuticals specific for PSMA, ranging from antibodies (mAb) to low-molecular weight molecules coupled to beta minus and alpha-emitting radionuclides for their use in targeted radionuclide therapy (TRT). TRT offers the possibility of selectively removing cancer tissue via the emission of radiation or radioactive particles within the tumour. In this article, the major milestones in PSMA ligand research and the therapeutic developments are summarised, together with a future perspective on the enhancement of current therapeutic approaches. Abstract Prostate cancer (PC) is the second most common cancer among men, with 1.3 million yearly cases worldwide. Among those cancer-afflicted men, 30% will develop metastases and some will progress into metastatic castration-resistant prostate cancer (mCRPC), which is associated with a poor prognosis and median survival time that ranges from nine to 13 months. Nevertheless, the discovery of prostate specific membrane antigen (PSMA), a marker overexpressed in the majority of prostatic cancerous tissue, revolutionised PC care. Ever since, PSMA-targeted radionuclide therapy has gained remarkable international visibility in translational oncology. Furthermore, on first clinical application, it has shown significant influence on therapeutic management and patient care in metastatic and hormone-refractory prostate cancer, a disease that previously had remained immedicable. In this article, we provide a general overview of the main milestones in the development of ligands for PSMA-targeted radionuclide therapy, ranging from the firstly developed monoclonal antibodies to the current state-of-the-art low molecular weight entities conjugated with various radionuclides, as well as potential future efforts related to PSMA-targeted radionuclide therapy.
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Affiliation(s)
- Mohamed El Fakiri
- Department of Nuclear Medicine, University Medical Center Freiburg, Faculty of Medicine, University of Freiburg, Hugstetter Str. 55, 79106 Freiburg, Germany; (M.E.F.); (N.M.G.); (N.A.); (A.-C.E.)
- Division of Radiopharmaceutical Development, German Cancer Consortium (DKTK), Partner Site Freiburg, and German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Nicolas M. Geis
- Department of Nuclear Medicine, University Medical Center Freiburg, Faculty of Medicine, University of Freiburg, Hugstetter Str. 55, 79106 Freiburg, Germany; (M.E.F.); (N.M.G.); (N.A.); (A.-C.E.)
- Division of Radiopharmaceutical Development, German Cancer Consortium (DKTK), Partner Site Freiburg, and German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Nawal Ayada
- Department of Nuclear Medicine, University Medical Center Freiburg, Faculty of Medicine, University of Freiburg, Hugstetter Str. 55, 79106 Freiburg, Germany; (M.E.F.); (N.M.G.); (N.A.); (A.-C.E.)
- Division of Radiopharmaceutical Development, German Cancer Consortium (DKTK), Partner Site Freiburg, and German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Matthias Eder
- Department of Nuclear Medicine, University Medical Center Freiburg, Faculty of Medicine, University of Freiburg, Hugstetter Str. 55, 79106 Freiburg, Germany; (M.E.F.); (N.M.G.); (N.A.); (A.-C.E.)
- Division of Radiopharmaceutical Development, German Cancer Consortium (DKTK), Partner Site Freiburg, and German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
- Correspondence: ; Tel.: +49-761-270-74220
| | - Ann-Christin Eder
- Department of Nuclear Medicine, University Medical Center Freiburg, Faculty of Medicine, University of Freiburg, Hugstetter Str. 55, 79106 Freiburg, Germany; (M.E.F.); (N.M.G.); (N.A.); (A.-C.E.)
- Division of Radiopharmaceutical Development, German Cancer Consortium (DKTK), Partner Site Freiburg, and German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
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Standardization of the [ 68Ga]Ga-PSMA-11 Radiolabeling Protocol in an Automatic Synthesis Module: Assessments for PET Imaging of Prostate Cancer. Pharmaceuticals (Basel) 2021; 14:ph14050385. [PMID: 33918987 PMCID: PMC8142994 DOI: 10.3390/ph14050385] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 03/06/2021] [Accepted: 03/09/2021] [Indexed: 11/16/2022] Open
Abstract
Prostate-specific membrane antigen (PSMA) is a glycoprotein present in the prostate, that is overexpressed in prostate cancer (PCa). Recently, PSMA-directed radiopharmaceuticals have been developed, allowing the pinpointing of tumors with the Positron Emission Tomography (PET) or Single Photon Emission Computed Tomography (SPECT) imaging techniques. The aim of the present work was to standardize and validate an automatic synthesis module-based radiolabeling protocol for [68Ga]Ga-PSMA-11, as well as to produce a radiopharmaceutical for PET imaging of PCa malignancies. [68Ga]Ga-PSMA-11 was evaluated to determine the radiochemical purity (RCP), stability in saline solution and serum, lipophilicity, affinity to serum proteins, binding and internalization to lymph node carcinoma of the prostate (LNCaP) cells, and ex vivo biodistribution in mice. The radiopharmaceutical was produced with an RCP of 99.06 ± 0.10%, which was assessed with reversed-phase high-performance liquid chromatography (RP-HPLC). The product was stable in saline solution for up to 4 h (RCP > 98%) and in serum for up to 1 h (RCP > 95%). The lipophilicity was determined as -3.80 ± 0.15, while the serum protein binding (SPB) was <17%. The percentages of binding to LNCaP cells were 4.07 ± 0.51% (30 min) and 4.56 ± 0.46% (60 min), while 19.22 ± 2.73% (30 min) and 16.85 ± 1.34% (60 min) of bound material was internalized. High accumulation of [68Ga]Ga-PSMA-11 was observed in the kidneys, spleen, and tumor, with a tumor-to-contralateral-muscle ratio of >8.5 and a tumor-to-blood ratio of >3.5. In conclusion, an automatic synthesis module-based radiolabeling protocol for [68Ga]Ga-PSMA-11 was standardized and the product was evaluated, thus verifying its characteristics for PET imaging of PCa tumors in a clinical environment.
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UĞur A, ElÇİ ŞG, YÜksel D. Validation of HPLC method for the determination of chemical andradiochemical purity of a 68Ga-labelled EuK-Sub-kf-(3-iodo-y-) DOTAGA. Turk J Chem 2021; 45:26-34. [PMID: 33679149 PMCID: PMC7925295 DOI: 10.3906/kim-2003-19] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 09/29/2020] [Indexed: 11/21/2022] Open
Abstract
The prostate-specific membrane antigen (PSMA) represents an ideal biomarker for molecular imaging. Various PSMA-targeted radioligands are available for prostate cancer imaging. In this study, labeling of PSMA I&T with 68Ga, as well as validation of the radiochemical purity of the synthesis product by reverse phase radio high-performance liquid chromatography (HPLC) method are intended. Since the standard procedure for the quality control (QC) was not available, definition of chemical and radiochemical purity of 68Ga-PSMA I&T was carried out according to the Q2 (R1) ICH guideline. The standard QC tests were analyzed with Scintomics 8100 radio-HPLC system equipped with a radioactivity detector. The method was evaluated in terms of linearity, precision and accuracy, LOQ, robustness parameters, and specificity. To assess the radiochemical and chemical purity of 68Ga-PSMA I&T, the developed method was validated to apply safely to patients. An excellent linearity was found between 1μg/mL and 30 μg/mL, with a limit of detection and limit of quantitation of 0.286 μg/mL and 0.866 μg/mL, respectively for 68Ga-PSMA I&T. The recovery was 96.8 ± 3.8%. The quality control of the final product was performed many times with validated radio-HPLC method and was found to comply with ICH requirements, thus demonstrating the accuracy and robustness of the method for routine clinical practice.
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Affiliation(s)
- Ayşe UĞur
- Department of Nuclear Medicine, Pamukkale University, Education and Research Hospital, Denizli Turkey
| | - Şükrü Gökhan ElÇİ
- Department of Biomedical Engineering, Faculty of Technology, Pamukkale University, Denizli Turkey
| | - Doğangün YÜksel
- Department of Nuclear Medicine, Medical Faculty, Pamukkale University, Denizli Turkey
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Völter F, Mittlmeier L, Gosewisch A, Brosch-Lenz J, Gildehaus FJ, Zacherl MJ, Beyer L, Stief CG, Holzgreve A, Rübenthaler J, Cyran CC, Böning G, Bartenstein P, Todica A, Ilhan H. Correlation of an Index-Lesion-Based SPECT Dosimetry Method with Mean Tumor Dose and Clinical Outcome after 177Lu-PSMA-617 Radioligand Therapy. Diagnostics (Basel) 2021; 11:diagnostics11030428. [PMID: 33802417 PMCID: PMC7999994 DOI: 10.3390/diagnostics11030428] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 02/18/2021] [Accepted: 02/25/2021] [Indexed: 12/31/2022] Open
Abstract
Background: Dosimetry can tailor prostate-specific membrane-antigen-targeted radioligand therapy (PSMA-RLT) for metastatic castration-resistant prostate cancer (mCRPC). However, whole-body tumor dosimetry is challenging in patients with a high tumor burden. We evaluate a simplified index-lesion-based single-photon emission computed tomography (SPECT) dosimetry method in correlation with clinical outcome. Methods: 30 mCRPC patients were included (median 71 years). The dosimetry was performed for the first cycle using quantitative 177Lu-SPECT. The response was evaluated using RECIST 1.1 and PERCIST criteria, as well as changes in PSMA-positive tumor volume (PSMA-TV) in post-therapy PSMA-PET and biochemical response according to PSA changes after two RLT cycles. Results: Mean tumor doses as well as index-lesion doses were significantly higher in PERCIST responders compared to non-responders (10.2 ± 12.0 Gy/GBq vs. 4.0 ± 2.9 Gy/GBq, p = 0.03 and 13.7 ± 14.2 Gy/GBq vs. 5.9 ± 4.4 Gy/GBq, p = 0.04, respectively). No significant differences in mean tumor and index lesion doses were observed between responders and non-responders according to RECIST 1.1, PSMA-TV, and biochemical response criteria. Conclusion: Compared to mean tumor doses on a patient level, single index-lesion-based SPECT dosimetry correlates equally well with the response to PSMA-RLT according to PERCIST criteria and may represent a fast and feasible dosimetry approach for clinical routine.
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Affiliation(s)
- Friederike Völter
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-University Munich, 80331 Munich, Germany; (F.V.); (L.M.); (A.G.); (J.B.-L.); (F.J.G.); (M.J.Z.); (L.B.); (A.H.); (G.B.); (P.B.); (A.T.)
| | - Lena Mittlmeier
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-University Munich, 80331 Munich, Germany; (F.V.); (L.M.); (A.G.); (J.B.-L.); (F.J.G.); (M.J.Z.); (L.B.); (A.H.); (G.B.); (P.B.); (A.T.)
| | - Astrid Gosewisch
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-University Munich, 80331 Munich, Germany; (F.V.); (L.M.); (A.G.); (J.B.-L.); (F.J.G.); (M.J.Z.); (L.B.); (A.H.); (G.B.); (P.B.); (A.T.)
| | - Julia Brosch-Lenz
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-University Munich, 80331 Munich, Germany; (F.V.); (L.M.); (A.G.); (J.B.-L.); (F.J.G.); (M.J.Z.); (L.B.); (A.H.); (G.B.); (P.B.); (A.T.)
| | - Franz Josef Gildehaus
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-University Munich, 80331 Munich, Germany; (F.V.); (L.M.); (A.G.); (J.B.-L.); (F.J.G.); (M.J.Z.); (L.B.); (A.H.); (G.B.); (P.B.); (A.T.)
| | - Mathias Johannes Zacherl
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-University Munich, 80331 Munich, Germany; (F.V.); (L.M.); (A.G.); (J.B.-L.); (F.J.G.); (M.J.Z.); (L.B.); (A.H.); (G.B.); (P.B.); (A.T.)
| | - Leonie Beyer
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-University Munich, 80331 Munich, Germany; (F.V.); (L.M.); (A.G.); (J.B.-L.); (F.J.G.); (M.J.Z.); (L.B.); (A.H.); (G.B.); (P.B.); (A.T.)
| | - Christian G. Stief
- Department of Urology, University Hospital, Ludwig-Maximilians-University Munich, 80331 Munich, Germany;
| | - Adrien Holzgreve
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-University Munich, 80331 Munich, Germany; (F.V.); (L.M.); (A.G.); (J.B.-L.); (F.J.G.); (M.J.Z.); (L.B.); (A.H.); (G.B.); (P.B.); (A.T.)
| | - Johannes Rübenthaler
- Department of Radiology, University Hospital, Ludwig-Maximilians-University Munich, 80331 Munich, Germany; (J.R.); (C.C.C.)
| | - Clemens C. Cyran
- Department of Radiology, University Hospital, Ludwig-Maximilians-University Munich, 80331 Munich, Germany; (J.R.); (C.C.C.)
| | - Guido Böning
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-University Munich, 80331 Munich, Germany; (F.V.); (L.M.); (A.G.); (J.B.-L.); (F.J.G.); (M.J.Z.); (L.B.); (A.H.); (G.B.); (P.B.); (A.T.)
| | - Peter Bartenstein
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-University Munich, 80331 Munich, Germany; (F.V.); (L.M.); (A.G.); (J.B.-L.); (F.J.G.); (M.J.Z.); (L.B.); (A.H.); (G.B.); (P.B.); (A.T.)
| | - Andrei Todica
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-University Munich, 80331 Munich, Germany; (F.V.); (L.M.); (A.G.); (J.B.-L.); (F.J.G.); (M.J.Z.); (L.B.); (A.H.); (G.B.); (P.B.); (A.T.)
| | - Harun Ilhan
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-University Munich, 80331 Munich, Germany; (F.V.); (L.M.); (A.G.); (J.B.-L.); (F.J.G.); (M.J.Z.); (L.B.); (A.H.); (G.B.); (P.B.); (A.T.)
- Correspondence: ; Tel.: +49-89-4400-77655
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Felber VB, Valentin MA, Wester HJ. Design of PSMA ligands with modifications at the inhibitor part: an approach to reduce the salivary gland uptake of radiolabeled PSMA inhibitors? EJNMMI Radiopharm Chem 2021; 6:10. [PMID: 33638060 PMCID: PMC7910394 DOI: 10.1186/s41181-021-00124-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 01/22/2021] [Indexed: 12/14/2022] Open
Abstract
AIM To investigate whether modifications of prostate-specific membrane antigen (PSMA)-targeted radiolabeled urea-based inhibitors could reduce salivary gland uptake and thus improve tumor-to-salivary gland ratios, several analogs of a high affinity PSMA ligand were synthesized and evaluated in in vitro and in vivo studies. METHODS Binding motifs were synthesized 'on-resin' or, when not practicable, in solution. Peptide chain elongations were performed according to optimized standard protocols via solid-phase peptide synthesis. In vitro experiments were performed using PSMA+ LNCaP cells. In vivo studies as well as μSPECT/CT scans were conducted with male LNCaP tumor xenograft-bearing CB17-SCID mice. RESULTS PSMA ligands with A) modifications within the central Zn2+-binding unit, B) proinhibitor motifs and C) substituents & bioisosteres of the P1'-γ-carboxylic acid were synthesized and evaluated. Modifications within the central Zn2+-binding unit of PSMA-10 (Glu-urea-Glu) provided three compounds. Thereof, only natLu-carbamate I (natLu-3) exhibited high affinity (IC50 = 7.1 ± 0.7 nM), but low tumor uptake (5.31 ± 0.94% ID/g, 1 h p.i. and 1.20 ± 0.55% ID/g, 24 h p.i.). All proinhibitor motif-based ligands (three in total) exhibited low binding affinities (> 1 μM), no notable internalization and very low tumor uptake (< 0.50% ID/g). In addition, four compounds with P1'-ɣ-carboxylate substituents were developed and evaluated. Thereof, only tetrazole derivative natLu-11 revealed high affinity (IC50 = 16.4 ± 3.8 nM), but also this inhibitor showed low tumor uptake (3.40 ± 0.63% ID/g, 1 h p.i. and 0.68 ± 0.16% ID/g, 24 h p.i.). Salivary gland uptake in mice remained at an equally low level for all compounds (between 0.02 ± 0.00% ID/g and 0.09 ± 0.03% ID/g), wherefore apparent tumor-to-submandibular gland and tumor-to-parotid gland ratios for the modified peptides were distinctly lower (factor 8-45) than for [177Lu]Lu-PSMA-10 at 24 h p.i. CONCLUSIONS The investigated compounds could not compete with the in vivo characteristics of the EuE-based PSMA inhibitor [177Lu]Lu-PSMA-10. Although two derivatives (3 and 11) were found to exhibit high affinities towards LNCaP cells, tumor uptake at 24 h p.i. was considerably low, while uptake in salivary glands remained unaffected. Optimization of the established animal model should be envisaged to enable a clear identification of PSMA-targeting radioligands with improved tumor-to-salivary gland ratios in future studies.
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Affiliation(s)
- Veronika Barbara Felber
- Technical University of Munich, Chair of Pharmaceutical Radiochemistry, Walther-Meißner-Str. 3, 85748, Garching, Germany.
| | - Manuel Amando Valentin
- Technical University of Munich, Chair of Pharmaceutical Radiochemistry, Walther-Meißner-Str. 3, 85748, Garching, Germany
| | - Hans-Jürgen Wester
- Technical University of Munich, Chair of Pharmaceutical Radiochemistry, Walther-Meißner-Str. 3, 85748, Garching, Germany
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Satpati D. Recent Breakthrough in 68Ga-Radiopharmaceuticals Cold Kits for Convenient PET Radiopharmacy. Bioconjug Chem 2021; 32:430-447. [PMID: 33630583 DOI: 10.1021/acs.bioconjchem.1c00010] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
68Ga-PET has emerged as an important diagnostic tool for precise detection and monitoring of oncological situations. Availability, cost, and radiosynthesis procedure are determining steps for success of a radioisotope/radiopharmaceutical in nuclear medicine. Availability of 68Ga from a 68Ge/68Ga generator containing a long-lived parent radioisotope (68Ge: t1/2 = 271 days) and an inexpensive, simplified production of 68Ga-radiopharmaceuticals through kit methodology has allowed smooth accommodation of 68Ga-PET in clinics. The uncomplicated formulation of 68Ga-radiopharmaceuticals from a lyophilized, cold kit is an impending breakthrough in clinical PET. The huge success of 68Ga in neuroendocrine tumor and prostate cancer imaging along with the regulatory approval of respective cold kits has opened a pathway for development of kits for other evolving radiotracers. There is a definite scope for increased participation of commercial manufacturers and distributors of cold kits to spread the potential of 68Ga worldwide across all the geographical locations and satellite centers.
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Affiliation(s)
- Drishty Satpati
- Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Mumbai-400085, India.,Homi Bhabha National Institute, Anushaktinagar, Mumbai-400094, India
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Lee CH, Lim I, Woo SK, Kim KI, Lee KC, Song K, Choi CW, Lim SM. The Feasibility of 64Cu-PSMA I&T PET for Prostate Cancer. Cancer Biother Radiopharm 2021; 37:417-423. [DOI: 10.1089/cbr.2020.4189] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Affiliation(s)
- Chul-Hee Lee
- Department of Nuclear Medicine, Korea Cancer Centre Hospital, Korea Institute of Radiological and Medical Sciences, Seoul, Republic of Korea
- Division of Applied RI, Research Institute of Radiological & Medical Sciences, Korea Institute of Radiological and Medical Sciences, Seoul, Republic of Korea
- Department of Urology, Korea Cancer Centre Hospital, Korea Institute of Radiological and Medical Sciences, Seoul, Republic of Korea
| | - Ilhan Lim
- Department of Nuclear Medicine, Korea Cancer Centre Hospital, Korea Institute of Radiological and Medical Sciences, Seoul, Republic of Korea
| | - Sang-Keun Woo
- Department of Nuclear Medicine, Korea Cancer Centre Hospital, Korea Institute of Radiological and Medical Sciences, Seoul, Republic of Korea
- Department of Nuclear Medicine, Seoul. National University Hospital, Seoul, Republic of Korea
| | - Kwang Il Kim
- Department of Nuclear Medicine, Seoul. National University Hospital, Seoul, Republic of Korea
| | - Kyo Chul Lee
- Department of Nuclear Medicine, Seoul. National University Hospital, Seoul, Republic of Korea
| | - Kanghyon Song
- Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
| | - Chang Woon Choi
- Department of Nuclear Medicine, Korea Cancer Centre Hospital, Korea Institute of Radiological and Medical Sciences, Seoul, Republic of Korea
| | - Sang Moo Lim
- Department of Nuclear Medicine, Korea Cancer Centre Hospital, Korea Institute of Radiological and Medical Sciences, Seoul, Republic of Korea
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Design and synthesis of a new conjugate of a tris(3-hydroxy-4-pyridinone) chelator (KC18) for potential use as gallium-68-labeled prostate-specific membrane antigen (PSMA) radiopharmaceutical. RESULTS IN CHEMISTRY 2021. [DOI: 10.1016/j.rechem.2021.100240] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
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Wurzer A, Parzinger M, Konrad M, Beck R, Günther T, Felber V, Färber S, Di Carlo D, Wester HJ. Preclinical comparison of four [ 18F, natGa]rhPSMA-7 isomers: influence of the stereoconfiguration on pharmacokinetics. EJNMMI Res 2020; 10:149. [PMID: 33284394 PMCID: PMC7721954 DOI: 10.1186/s13550-020-00740-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 11/24/2020] [Indexed: 12/27/2022] Open
Abstract
Introduction Radiohybrid (rh) ligands, a novel class of prostate-specific membrane antigen (PSMA)-targeted radiopharmaceuticals, can be labeled either with [18F]fluorine via isotopic exchange or with radiometals (such as [68Ga]Gallium, [177Lu]Lutetium, [225Ac]Actinium). Among these, [18F, natGa]rhPSMA-7 has recently entered clinical assessment.
Aim Since [18F, natGa]rhPSMA-7 is composed of four stereoisomers ([18F, natGa]rhPSMA-7.1, -7.2, -7.3 and -7.4), we initiated a preclinical selection process to identify the isomer with the most favorable pharmacokinetics for further clinical investigation. Methods A synthetic protocol for enantiopure [19F, natGa]rhPSMA-7 isomers has been developed. The comparative evaluation of the four isomers comprised human serum albumin binding, lipophilicity, IC50, internalization and classical biodistribution studies and competition experiments in LNCaP tumor-bearing CB-17 SCID mice. In addition, a radio high-performance liquid chromatography-based method was developed allowing quantitative, intraindividual comparison of [18F, natGa]rhPSMA-7.1 to -7.4 in LNCaP tumor-bearing mice. Results Cell studies revealed high PSMA affinity and internalization for [18/19F, natGa]rhPSMA-7.2, -7.3 and -7.4, whereas [18/19F, natGa]rhPSMA-7.1 showed approximately twofold lower values. Although the biodistribution profile obtained was typical of PSMA inhibitors, it did not allow for selection of a lead candidate for clinical studies. Thus, an intraindividual comparison of all four isomers in LNCaP tumor-bearing mice was carried out by injection of a diastereomeric mixture, followed by analysis of the differential uptake and excretion pattern of each isomer. Based on its high tumor accumulation and low uptake in blood, liver and kidneys, [18F, natGa]rhPSMA-7.3 was identified as the preferred isomer and transferred into clinical studies. Conclusion [18F, natGa]rhPSMA-7.3 has been selected as a lead compound for clinical development of a [18F]rhPSMA-based candidate. The intraindividual differential uptake and excretion analysis in vivo allowed for an accurate comparison and assessment of radiopharmaceuticals.
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Affiliation(s)
- Alexander Wurzer
- Chair of Pharmaceutical Radiochemistry, Technical University of Munich, Walther-Meißner-Str. 3, 85748, Garching, Germany.
| | - Mara Parzinger
- Chair of Pharmaceutical Radiochemistry, Technical University of Munich, Walther-Meißner-Str. 3, 85748, Garching, Germany
| | - Matthias Konrad
- Chair of Pharmaceutical Radiochemistry, Technical University of Munich, Walther-Meißner-Str. 3, 85748, Garching, Germany
| | - Roswitha Beck
- Chair of Pharmaceutical Radiochemistry, Technical University of Munich, Walther-Meißner-Str. 3, 85748, Garching, Germany
| | - Thomas Günther
- Chair of Pharmaceutical Radiochemistry, Technical University of Munich, Walther-Meißner-Str. 3, 85748, Garching, Germany
| | - Veronika Felber
- Chair of Pharmaceutical Radiochemistry, Technical University of Munich, Walther-Meißner-Str. 3, 85748, Garching, Germany
| | - Stefanie Färber
- Chair of Pharmaceutical Radiochemistry, Technical University of Munich, Walther-Meißner-Str. 3, 85748, Garching, Germany
| | - Daniel Di Carlo
- Chair of Pharmaceutical Radiochemistry, Technical University of Munich, Walther-Meißner-Str. 3, 85748, Garching, Germany
| | - Hans-Jürgen Wester
- Chair of Pharmaceutical Radiochemistry, Technical University of Munich, Walther-Meißner-Str. 3, 85748, Garching, Germany
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Zhao R, Ploessl K, Zha Z, Choi S, Alexoff D, Zhu L, Kung HF. Synthesis and Evaluation of 68Ga- and 177Lu-Labeled ( R)- vs ( S)-DOTAGA Prostate-Specific Membrane Antigen-Targeting Derivatives. Mol Pharm 2020; 17:4589-4602. [PMID: 33108189 DOI: 10.1021/acs.molpharmaceut.0c00777] [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] [Indexed: 12/15/2022]
Abstract
Prostate-specific membrane antigen (PSMA) is overexpressed in prostate cancer cells and therefore is an attractive target for prostate cancer diagnosis and radionuclide therapy. Recently, published results from clinical studies using a new PSMA-targeting PET imaging agent, [68Ga]Ga-PSMA-093 ([68Ga]Ga-HBED-CC-O-carboxymethyl-Tyr-CO-NH-Glu), support the development of this agent for the diagnosis of prostate cancer. In this study, the HBED-CC chelating group in PSMA-093 was replaced by stereoselective (R)- or (S)-DOTAGA. This chelating group serves not only for chelating 68Ga but is also amendable for complexing other radioactive metals for radionuclide therapy. The corresponding optically pure (R)- and (S)-[68Ga/177Lu]-DOTAGA derivatives, (R)-[68Ga/177Lu]-13 and (S)-[68Ga/177Lu]-13, were successfully prepared. Comparison of radiolabeling, binding affinity, cell uptake, and biodistribution between the two isomers was performed. Radiolabeling of (R)-[177Lu]Lu-13 and (S)-[177Lu]Lu-13 at 50 °C suggested that rates of complex formation were time-dependent and the formation of (S)-[177Lu]Lu-13 was distinctly faster. The rates of complex formation for the corresponding 68Ga agents were comparable between structural isomers. The natGa and natLu equivalents showed high binding PSMA affinity (IC50 = 24-111 nM), comparable to that of the parent agent, [natGa]Ga-PSMA-093 (IC50 = 34.0 nM). Results of cell uptake and biodistribution studies in PSMA-expressing PC3-PIP tumor-bearing mice appeared to show no difference between the labeled (R)- and (S)-isomers. This is the first time that a pair of [68Ga/177Lu]-(R)- and (S)-DOTAGA isomers of PSMA agents were evaluated. Results of biological studies between the isomers showed no noticeable difference; however, the distinctions on the rate of Lu complex formation should be considered in the development of new 177Lu-DOTAGA-based radionuclide therapy agents in the future.
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Affiliation(s)
- Ruiyue Zhao
- College of Chemistry, Beijing Normal University, Beijing 100875, PR China
| | - Karl Ploessl
- Five Eleven Pharma Inc., Philadelphia, Pennsylvania 19104, United States
| | - Zhihao Zha
- Five Eleven Pharma Inc., Philadelphia, Pennsylvania 19104, United States
| | - Seokrye Choi
- Five Eleven Pharma Inc., Philadelphia, Pennsylvania 19104, United States
| | - David Alexoff
- Five Eleven Pharma Inc., Philadelphia, Pennsylvania 19104, United States
| | - Lin Zhu
- College of Chemistry, Beijing Normal University, Beijing 100875, PR China
| | - Hank F Kung
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.,Five Eleven Pharma Inc., Philadelphia, Pennsylvania 19104, United States
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Pastorino S, Riondato M, Uccelli L, Giovacchini G, Giovannini E, Duce V, Ciarmiello A. Toward the Discovery and Development of PSMA Targeted Inhibitors for Nuclear Medicine Applications. Curr Radiopharm 2020; 13:63-79. [PMID: 31362683 PMCID: PMC7509769 DOI: 10.2174/1874471012666190729151540] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 07/15/2019] [Accepted: 07/15/2019] [Indexed: 11/22/2022]
Abstract
BACKGROUND The rising incidence rate of prostate cancer (PCa) has promoted the development of new diagnostic and therapeutic radiopharmaceuticals during the last decades. Promising improvements have been achieved in clinical practice using prostate specific membrane antigen (PSMA) labeled agents, including specific antibodies and small molecular weight inhibitors. Focusing on molecular docking studies, this review aims to highlight the progress in the design of PSMA targeted agents for a potential use in nuclear medicine. RESULTS Although the first development of radiopharmaceuticals able to specifically recognize PSMA was exclusively oriented to macromolecule protein structure such as radiolabeled monoclonal antibodies and derivatives, the isolation of the crystal structure of PSMA served as the trigger for the synthesis and the further evaluation of a variety of low molecular weight inhibitors. Among the nuclear imaging probes and radiotherapeutics that have been developed and tested till today, labeled Glutamate-ureido inhibitors are the most prevalent PSMA-targeting agents for nuclear medicine applications. CONCLUSION PSMA represents for researchers the most attractive target for the detection and treatment of patients affected by PCa using nuclear medicine modalities. [99mTc]MIP-1404 is considered the tracer of choice for SPECT imaging and [68Ga]PSMA-11 is the leading diagnostic for PET imaging by general consensus. [18F]DCFPyL and [18F]PSMA-1007 are clearly the emerging PET PSMA candidates for their great potential for a widespread commercial distribution. After paving the way with new imaging tools, academic and industrial R&Ds are now focusing on the development of PSMA inhibitors labeled with alpha or beta minus emitters for a theragnostic application.
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Affiliation(s)
- Sara Pastorino
- Nuclear Medicine Department, S. Andrea Hospital, Via Vittorio Veneto 197, 19124 La Spezia, Italy
| | - Mattia Riondato
- Nuclear Medicine Department, S. Andrea Hospital, Via Vittorio Veneto 197, 19124 La Spezia, Italy
| | - Licia Uccelli
- Morphology, Surgery and Experimental Medicine Department, University of Ferrara, Via L. Borsari 46, 44121 Ferrara, Italy.,Nuclear Medicine Unit, University Hospital, Via Aldo Moro 8, 44124 Ferrara, Italy
| | - Giampiero Giovacchini
- Nuclear Medicine Department, S. Andrea Hospital, Via Vittorio Veneto 197, 19124 La Spezia, Italy
| | - Elisabetta Giovannini
- Nuclear Medicine Department, S. Andrea Hospital, Via Vittorio Veneto 197, 19124 La Spezia, Italy
| | - Valerio Duce
- Nuclear Medicine Department, S. Andrea Hospital, Via Vittorio Veneto 197, 19124 La Spezia, Italy
| | - Andrea Ciarmiello
- Nuclear Medicine Department, S. Andrea Hospital, Via Vittorio Veneto 197, 19124 La Spezia, Italy
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Zacherl MJ, Gildehaus FJ, Mittlmeier L, Böning G, Gosewisch A, Wenter V, Unterrainer M, Schmidt-Hegemann N, Belka C, Kretschmer A, Casuscelli J, Stief CG, Unterrainer M, Bartenstein P, Todica A, Ilhan H. First Clinical Results for PSMA-Targeted α-Therapy Using 225Ac-PSMA-I&T in Advanced-mCRPC Patients. J Nucl Med 2020; 62:669-674. [PMID: 33008928 DOI: 10.2967/jnumed.120.251017] [Citation(s) in RCA: 81] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 08/27/2020] [Indexed: 12/12/2022] Open
Abstract
Treatment of advanced metastatic castration-resistant prostate cancer after failure of approved therapy options remains challenging. Prostate-specific membrane antigen (PSMA)-targeting β- and α-emitters have been introduced, with promising response rates. Here, we present the first-to our knowledge-clinical data for PSMA-targeted α-therapy (TAT) using 225Ac-PSMA imaging and therapy (I&T). Methods: Fourteen patients receiving 225Ac-PSMA-I&T were included in this retrospective analysis. Eleven of the 14 had prior second-line antiandrogen treatment with abiraterone or enzalutamide, prior chemotherapy, and prior 177Lu-PSMA treatment. Patients were treated at bimonthly intervals until progression or intolerable side effects. Prostate-specific antigen (PSA) was measured for response assessment. Hematologic and nonhematologic side effects were recorded according to the Common Terminology Criteria for Adverse Events, version 5.0. Results: Thirty-four cycles of 225Ac-PSMA-I&T were applied (median dose, 7.8 MBq; range, 6.0-8.5), with 1 cycle in 3 patients, 2 cycles in 7 patients, 4 cycles in 3 patients, and 5 cycles in 1 patient. No acute toxicity was observed during hospitalization. Baseline PSA was 112 ng/mL (range, 20.5-818 ng/mL). The best PSA response after TAT (a PSA decline ≥ 50%) was observed in 7 patients, and a PSA decline of any amount was observed in 11 patients. Three patients had no PSA decline at any time. A subgroup analysis of 11 patients with prior 177Lu-PSMA treatment showed any PSA decline in 8 patients and a decline of at least 50% in 5 patients. After TAT, grade 3 anemia was observed in 3 of the 14 patients, with 2 of them presenting with grade 2 anemia already at baseline. Grade 3 leukopenia was observed in 1 patient. Eight patients with preexisting xerostomia after 177Lu-PSMA showed no worsening after TAT. Newly diagnosed grade 1 or 2 xerostomia after TAT was observed in 5 patients. One patient reported no xerostomia at all. Conclusion: Our first clinical data for TAT using 225Ac-PSMA-I&T showed a promising antitumor effect in advanced metastatic castration-resistant prostate cancer. These results are highly comparable to data on 225Ac-PSMA-617 TAT.
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Affiliation(s)
| | | | - Lena Mittlmeier
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Guido Böning
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Astrid Gosewisch
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Vera Wenter
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Marcus Unterrainer
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany.,Department of Radiation Oncology, University Hospital, LMU Munich, Munich, Germany
| | | | - Claus Belka
- Department of Radiation Oncology, University Hospital, LMU Munich, Munich, Germany
| | | | - Jozefina Casuscelli
- Department of Urology, University Hospital, LMU Munich, Munich, Germany; and
| | - Christian G Stief
- Department of Urology, University Hospital, LMU Munich, Munich, Germany; and
| | - Marcus Unterrainer
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany.,Department of Radiology, University Hospital, LMU Munich, Munich, Germany
| | - Peter Bartenstein
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Andrei Todica
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Harun Ilhan
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
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Çelen S, Gültekin A, Özlülerden Y, Mete A, Sağtaş E, Ufuk F, Yüksel D, Yağcı B, Zümrütbaş AE. Comparison of 68Ga-PSMA-I/T PET-CT and Multiparametric MRI for Locoregional Staging of Prostate Cancer Patients: A Pilot Study. Urol Int 2020; 104:684-691. [PMID: 32750695 DOI: 10.1159/000509974] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Accepted: 07/04/2020] [Indexed: 11/19/2022]
Abstract
BACKGROUND/AIM The objective of this work was to assess the value of 68Ga-DOTAGA-(3-iodo-y)fk(Sub-KuE) positron emission tomography (68Ga-PSMA-I/T PET-CT) and multiparametric magnetic resonance imaging (mp-MRI) for preoperative staging in prostate cancer (PCa) patients who underwent radical prostatectomy (RP) by validating with postoperative histopathology data. MATERIALS AND METHODS We prospectively investigated 30 consecutive PCa patients who had both mp-MRI and 68Ga-PSMA-I/T PET-CT before laparoscopic RP. The seminal vesicle invasion (SVI), lymph node metastasis (LNM), bladder neck invasion (BNI), and extracapsular extension (ECE) were investigated separately. The diagnostic performances of mp-MRI and 68Ga-PSMA-I/T PET-CT were assessed using histopathological results. RESULTS Both mp-MRI and 68Ga-PSMA-I/T PET-CT were not statistically significant in the evaluation of SVI, BNI, and ECE preoperatively but had statistically significant results in the assessment of LNM. mp-MRI had higher overall sensitivity for ECE, overall specificity for SVI, ECE, and BNI, and positive predictive value for ECE, SVI, BNI. 68Ga-PSMA-I/T PET-CT had higher overall sensitivity for BNI, and negative predictive value for BNI and LNM. CONCLUSION mp-MRI has superior specificity, sensitivity, and accuracy for assessing ECE and SVI. Both imaging modalities had similar specificity, sensitivity, and accuracy for determining BNI. However, both imaging modalities had low diagnostic accuracy for LNM on histopathology.
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Affiliation(s)
- Sinan Çelen
- Department of Urology, Faculty of Medicine, University of Pamukkale, Denizli, Turkey,
| | - Aziz Gültekin
- Department of Nuclear Medicine, Faculty of Medicine, University of Pamukkale, Denizli, Turkey
| | - Yusuf Özlülerden
- Department of Urology, Faculty of Medicine, University of Pamukkale, Denizli, Turkey
| | - Aslı Mete
- Department of Anesthesiology, Faculty of Medicine, University of Pamukkale, Denizli, Turkey
| | - Ergin Sağtaş
- Department of Radiology, Faculty of Medicine, University of Pamukkale, Denizli, Turkey
| | - Furkan Ufuk
- Department of Radiology, Faculty of Medicine, University of Pamukkale, Denizli, Turkey
| | - Doğangün Yüksel
- Department of Nuclear Medicine, Faculty of Medicine, University of Pamukkale, Denizli, Turkey
| | - Baki Yağcı
- Department of Radiology, Faculty of Medicine, University of Pamukkale, Denizli, Turkey
| | - Ali Ersin Zümrütbaş
- Department of Urology, Faculty of Medicine, University of Pamukkale, Denizli, Turkey
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Tateishi U. Prostate-specific membrane antigen (PSMA)-ligand positron emission tomography and radioligand therapy (RLT) of prostate cancer. Jpn J Clin Oncol 2020; 50:349-356. [PMID: 32147685 PMCID: PMC7160915 DOI: 10.1093/jjco/hyaa004] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 12/11/2019] [Accepted: 01/07/2020] [Indexed: 01/29/2023] Open
Abstract
From a clinical perspective, prostate-specific membrane antigen (PSMA) is a valuable target for both diagnosis and radioligand therapy (RLT) of prostate cancer. The term ‘specific’ has been used to characterize a histologic hallmark of overexpression in the membrane of most prostate cancer. Many PSMA ligands have been developed since the previous decade and have been used in several clinical trials and clinical studies. However, procedure, specification, protocol, interpretation criteria, radiation dose, and cost-effectiveness of PSMA ligands have not been fully explained. Regardless of worldwide use of promising PSMA-ligand PET and RLT, it has not been approved in Japan. Expedited introduction of PSMA-ligand PET and RLT to Japan and implementation of clinical study are eager for many patients with prostate cancer.
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Affiliation(s)
- Ukihide Tateishi
- Department of Diagnostic Radiology, Tokyo Medical and Dental University, Tokyo
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Wurzer A, Di Carlo D, Schmidt A, Beck R, Eiber M, Schwaiger M, Wester HJ. Radiohybrid Ligands: A Novel Tracer Concept Exemplified by 18F- or 68Ga-Labeled rhPSMA Inhibitors. J Nucl Med 2020; 61:735-742. [PMID: 31862804 PMCID: PMC7198388 DOI: 10.2967/jnumed.119.234922] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 09/27/2019] [Indexed: 11/16/2022] Open
Abstract
When we critically assess the reason for the current dominance of 68Ga-labeled peptides and peptide-like ligands in radiopharmacy and nuclear medicine, we have to conclude that the major advantage of such radiopharmaceuticals is the apparent lack of suitable 18F-labeling technologies with proven clinical relevance. To prepare and to subsequently perform a clinical proof-of-concept study on the general suitability of silicon-fluoride-acceptor (SiFA)-conjugated radiopharmaceuticals, we developed inhibitors of the prostate-specific membrane antigen (PSMA) that are labeled by isotopic exchange (IE). To compensate for the pronounced lipophilicity of the SiFA unit, we used metal chelates, conjugated in close proximity to SiFA. Six different radiohybrid PSMA ligands (rhPSMA ligands) were evaluated and compared with the commonly used 18F-PSMA inhibitors 18F-DCFPyL and 18F-PSMA-1007. Methods: All inhibitors were synthesized by solid-phase peptide synthesis. Human serum albumin binding was measured by affinity high-performance liquid chromatography, whereas the lipophilicity of each tracer was determined by the n-octanol/buffer method. In vitro studies (IC50, internalization) were performed on LNCaP cells. Biodistribution studies were conducted on LNCaP tumor-bearing male CB-17 SCID mice. Results: On the laboratory scale (starting activities, 0.2-9.0 GBq), labeling of 18F-rhPSMA-5 to -10 by IE was completed in < 20 min (radiochemical yields, 58% ± 9%; radiochemical purity, >97%) with molar activities of 12-60 GBq/μmol. All rhPSMAs showed low nanomolar affinity and high internalization by PSMA-expressing cells when compared with the reference radiopharmaceuticals, medium-to-low lipophilicity, and high human serum albumin binding. Biodistribution studies in LNCaP tumor-bearing mice revealed high tumor uptake, sufficiently fast clearance kinetics from blood, low hepatobiliary excretion, fast renal excretion, and very low uptake of 18F activity in bone. Conclusion: The novel 18F-rhPSMA radiopharmaceuticals developed under the radiohybrid concept show equal or better targeting characteristics than the established 18F-PSMA tracers 18F-DCFPyL and 18F-PSMA-1007. The unparalleled simplicity of production, the possibility to produce the identical 68Ga-labeled 19F-68Ga-rhPSMA tracers, and the possibility to extend this concept to true theranostic radiohybrid radiopharmaceuticals, such as F-Lu-rhPSMA, are unique features of these radiopharmaceuticals.
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Affiliation(s)
- Alexander Wurzer
- Chair of Pharmaceutical Radiochemistry, Technical University of Munich, Garching, Germany; and
| | - Daniel Di Carlo
- Chair of Pharmaceutical Radiochemistry, Technical University of Munich, Garching, Germany; and
| | - Alexander Schmidt
- Chair of Pharmaceutical Radiochemistry, Technical University of Munich, Garching, Germany; and
| | - Roswitha Beck
- Chair of Pharmaceutical Radiochemistry, Technical University of Munich, Garching, Germany; and
| | - Matthias Eiber
- Department of Nuclear Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Markus Schwaiger
- Department of Nuclear Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Hans-Jürgen Wester
- Chair of Pharmaceutical Radiochemistry, Technical University of Munich, Garching, Germany; and
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50
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PSMA-positive nodal recurrence in prostate cancer : Salvage radiotherapy is superior to salvage lymph node dissection in retrospective analysis. Strahlenther Onkol 2020; 196:637-646. [PMID: 32211942 PMCID: PMC7305083 DOI: 10.1007/s00066-020-01605-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 03/09/2020] [Indexed: 01/08/2023]
Abstract
PURPOSE This analysis compares salvage lymph node dissection (SLND) to salvage lymph node radiotherapy (SLNRT) of 68Ga-PSMA PET-positive nodal recurrences after radical prostatectomy (RPE). METHODS A total of 67 SLNRT and 33 SLND consecutive patients with pelvic and/or para-aortic nodal recurrences after RPE were retrospectively analyzed. Biochemical recurrence-free survival rates (bRFS; PSA <0.2 ng/mL) were calculated according to Kaplan-Meier and survival curves were compared using the log rank test. For multivariable analysis, binary logistic regression analysis was performed (p < 0.05). RESULTS Median follow-up was 17 months (range, 6-53 months) in SLND patients and 31 months (range, 3-56 months) in SLNRT patients (p = 0.027). SLNRT patients had significantly more tumours of pT3 and pT4 category (82% vs. 67%; p = 0.006), pathologically involved lymph nodes (45% vs. 27%; p = 0.001) and positive surgical margins (54% vs. 12%; p = 0.001) at time of RPE than SLND patients. PSA persistence after RPE was significantly more frequently observed in the SLNRT cohort (73% vs. 27%; p = 0.001). There was no significant difference in the distribution of PET-positive lymph nodes. Median PSA before SLND was higher than before SLNRT (3.07 ng/ml vs. 1.3 ng/ml; p = 0.393). The 2‑year bRFS was significantly higher in the SLNRT vs. the SLND cohort (92% vs. 30%; p = 0.001) with lower rates of distant metastases (21% vs. 52%; p = 0.002) and secondary treatments (5% vs. 39%; p = 0.011) irrespective of ongoing androgen deprivation therapy at last contact. In multivariable analysis, SLNRT was significantly associated with prolonged bRFS (regression coefficient 1.436, hazard ratio 4.204, 95% CI 1.789-9.878; p = 0.001). CONCLUSION Based on this retrospective study SLNRT might be the preferred treatment option for patients with nodal recurrence after previous RPE.
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