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Beheshti M, Vali R, Zarehparvar Moghadam S, Amini H, Hakiminejad M, Divband G. Complete Resolution of Locally Advanced Prostate Cancer After Molecular Endoradiotherapy With 177 Lu-PSMA. Clin Nucl Med 2024; 49:e276-e277. [PMID: 38537212 DOI: 10.1097/rlu.0000000000005163] [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: 05/06/2024]
Abstract
ABSTRACT A 76-year-old man with castration-resistant prostate cancer underwent 68 Ga-prostate-specific membrane antigen (PSMA) PET/CT for restaging. A large PSMA-avid tumor with invasion to adjacent organs was noted causing gross hematuria and symptomatic anemia. Two cycles of 177 Lu-PSMA were administered, and the patient showed significant reduction of hematuria as well as declining in PSA levels. 177 Lu-PSMA therapy can be a good treatment option in patients with locally invasive tumors.
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Affiliation(s)
- Mohsen Beheshti
- From the Division of Molecular Imaging and Theranostics, Department of Nuclear Medicine, University Hospital Salzburg, Paracelsus Medical University, Salzburg, Austria
| | - Reza Vali
- Division of Nuclear Medicine, Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto, Ontario, Canada
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Machulkin AE, Petrov SA, Bodenko V, Larkina MS, Plotnikov E, Yuldasheva F, Tretyakova M, Bezverkhniaia E, Zyk NY, Stasyuk E, Zelchan R, Majouga AG, Tolmachev V, Orlova A, Beloglazkina EK, Yusubov MS. Synthesis and Preclinical Evaluation of Urea-Based Prostate-Specific Membrane Antigen-Targeted Conjugates Labeled with 177Lu. ACS Pharmacol Transl Sci 2024; 7:1457-1473. [PMID: 38751647 PMCID: PMC11092120 DOI: 10.1021/acsptsci.4c00070] [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: 02/07/2024] [Revised: 04/19/2024] [Accepted: 04/24/2024] [Indexed: 05/18/2024]
Abstract
177Lu-labeled small-molecule prostate-specific membrane antigen (PSMA) targeted tracers are therapeutic agents for metastatic castration-resistant prostate cancer. Optimizing molecular design holds the potential to further enhance the pharmacokinetic properties of PSMA-targeted agents while preserving their potent therapeutic effects. In this study, six novel N-[N-[(S)-1,3-dicarboxypropyl]carbamoyl]-(S)-l-lysine (DCL) urea-based PSMA ligand 2,2',2″,2‴-(1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrayl)tetraacetic acid conjugates were synthesized. These conjugates feature polypeptide linkers containing the Phe-Phe peptide sequence and an aromatic fragment at the ε-NH-Lys group of the DCL fragment. The synthesis yielded products with satisfactory yields ranging from 60% to 72%, paving the way for their preclinical evaluation. The labeling of the new variants of urea-based PSMA inhibitors provided a radiochemical yield of over 95%. The 177Lu-labeled conjugates demonstrated specific and moderate affinity binding to PSMA-expressing human cancer cells PC3-pip in vitro and specific accumulation in PSMA-expressing xenografts in vivo. Based on the results, both the lipophilicity and the type of substituent in the linker significantly influence the binding properties of the PSMA inhibitor and its biodistribution profile. Specifically, the studied variants containing a bromine substituent or a hydroxyl group introduced into the aromatic fragment of the phenylalanyl residue in DCL exhibit higher affinities to PSMA compared to variants with only a chlorine-substituted aromatic fragment or variants without any substituents. The [177Lu]Lu-13C with the bromine substituent was characterized by the highest activity accumulation in blood, salivary glands, muscle, bone, and gastrointestinal tract and had inasmuch as an unfavorable pharmacokinetic profile. The negative charge of the carboxyl group in the phenyl moiety of the [177Lu]Lu-13A variant has demonstrated a positive effect on reducing the retention of activity in the liver and the kidneys (the ratio of tumor to kidneys was 1.3-fold). Low accumulation in normal tissues in vivo indicates that this novel PSMA-targeting inhibitor is a promising radioligand.
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Affiliation(s)
- Aleksei E. Machulkin
- Department
of Chemistry, M.V. Lomonosov Moscow State
University, Leninskie
Gory 1-3, Moscow 119991, Russian Federation
- Department
for Biochemistry, People’s Friendship
University of Russia Named after Patrice Lumumba (RUDN University), Moscow 117198, Russia
| | - Stanislav A. Petrov
- Department
of Chemistry, M.V. Lomonosov Moscow State
University, Leninskie
Gory 1-3, Moscow 119991, Russian Federation
| | - Vitalina Bodenko
- Research
Centrum for Oncotheranostics, Research School of Chemistry and Applied
Biomedical Sciences, Tomsk Polytechnic University, Tomsk 634050, Russia
- Scientific
and Educational Laboratory of Chemical and Pharmaceutical Research, Siberian State Medical University, Tomsk 634050, Russia
| | - Mariia S. Larkina
- Research
Centrum for Oncotheranostics, Research School of Chemistry and Applied
Biomedical Sciences, Tomsk Polytechnic University, Tomsk 634050, Russia
- Department
of Pharmaceutical Analysis, Siberian State
Medical University, Tomsk 634050, Russia
| | - Evgenii Plotnikov
- Research
Centrum for Oncotheranostics, Research School of Chemistry and Applied
Biomedical Sciences, Tomsk Polytechnic University, Tomsk 634050, Russia
- Mental
Health Research Institute, Tomsk National Research Medical Center, Russian Academy of Sciences, Tomsk 634014, Russia
| | - Feruza Yuldasheva
- Research
Centrum for Oncotheranostics, Research School of Chemistry and Applied
Biomedical Sciences, Tomsk Polytechnic University, Tomsk 634050, Russia
| | - Maria Tretyakova
- Research
Centrum for Oncotheranostics, Research School of Chemistry and Applied
Biomedical Sciences, Tomsk Polytechnic University, Tomsk 634050, Russia
| | - Ekaterina Bezverkhniaia
- Research
Centrum for Oncotheranostics, Research School of Chemistry and Applied
Biomedical Sciences, Tomsk Polytechnic University, Tomsk 634050, Russia
- Department
of Medicinal Chemistry, Uppsala University, Uppsala 75183, Sweden
| | - Nikolay Yu. Zyk
- Department
of Chemistry, M.V. Lomonosov Moscow State
University, Leninskie
Gory 1-3, Moscow 119991, Russian Federation
| | - Elena Stasyuk
- School of
Nuclear Science and Engineering, Tomsk Polytechnic
University, Tomsk 634050, Russia
| | - Roman Zelchan
- Research
Centrum for Oncotheranostics, Research School of Chemistry and Applied
Biomedical Sciences, Tomsk Polytechnic University, Tomsk 634050, Russia
| | - Alexander G. Majouga
- Dmitry
Mendeleev University of Chemical Technology of Russia, Miusskaya sq. 9, Moscow 125047, Russian Federation
| | - Vladimir Tolmachev
- Department
of Immunology, Genetics and Pathology, Uppsala
University, Uppsala 75185, Sweden
| | - Anna Orlova
- Department
of Medicinal Chemistry, Uppsala University, Uppsala 75183, Sweden
| | - Elena K. Beloglazkina
- Department
of Chemistry, M.V. Lomonosov Moscow State
University, Leninskie
Gory 1-3, Moscow 119991, Russian Federation
| | - Mekhman S. Yusubov
- Research
Centrum for Oncotheranostics, Research School of Chemistry and Applied
Biomedical Sciences, Tomsk Polytechnic University, Tomsk 634050, Russia
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Wurzer A, De Rose F, Fischer S, Schwaiger M, Weber W, Nekolla S, Wester HJ, Eiber M, D'Alessandria C. Preclinical comparison of [ 177Lu]Lu-rhPSMA-10.1 and [ 177Lu]Lu-rhPSMA-10.2 for endoradiotherapy of prostate cancer: biodistribution and dosimetry studies. EJNMMI Radiopharm Chem 2024; 9:18. [PMID: 38407630 PMCID: PMC10897098 DOI: 10.1186/s41181-024-00246-2] [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: 01/18/2024] [Accepted: 02/20/2024] [Indexed: 02/27/2024] Open
Abstract
BACKGROUND Radiohybrid PSMA-targeted ligands (rhPSMA) have been introduced as a novel platform for theranostic applications. Among a variety of rhPSMA-ligands developed for radioligand therapy, two stereoisomers [177Lu]Lu-rhPSMA-10.1 and -10.2 have been synthesized and initially characterized in preclinical experiments with the aim to provide an optimized binding profile to human serum albumin, a reduction of charge, and thus accelerated kidney excretion, and unaffected or even improved tumor uptake. As both isomers showed similar in vitro characteristics and tumor uptake at 24 h post injection in tumor bearing mice and in order to identify the isomer with the most favorable pharmacokinetics for radioligand therapy, we carried out in-depth biodistribution and dosimetry studies in tumor-bearing and healthy mice. RESULTS rhPSMA-10.1 and -10.2 were radiolabeled with lutetium-177 according to the established procedures of other DOTA-based PSMA ligands and displayed a high and comparable stability in all buffers and human serum (> 97%, 24 h). Biodistribution studies revealed fast clearance from the blood pool (0.3-0.6%ID/g at 1 h) and other background tissues within 48 h. Distinctive differences were found in the kidneys, where [177Lu]Lu-rhPSMA-10.1 displayed lower initial uptake and faster excretion kinetics compared to [177Lu]Lu-rhPSMA-10.2 expressed by a 1.5-fold and ninefold lower uptake value at 1 h and 24 h in healthy animals, respectively. Tumor uptake was comparable and in the range of 8.6-11.6%ID/g for both isomers over 24 h and was maintained up to 168 h at a level of 2.2 ± 0.8 and 4.1 ± 1.4%ID/g for [177Lu]Lu-rhPSMA-10.1 and [177Lu]Lu-rhPSMA-10.2, respectively. CONCLUSION Our preclinical data on biodistribution and dosimetry indicate a more favorable profile of [177Lu]Lu-rhPSMA-10.1 compared to [177Lu]Lu-rhPSMA-10.2 for PSMA-targeted radioligand therapy. [177Lu]Lu-rhPSMA-10.1 shows fast kidney clearance kinetics resulting in excellent tumor-to-organ ratios over a therapy relevant time course. Meanwhile, [177Lu]Lu-rhPSMA-10.1 is currently being investigated in clinical phase I/II studies in patients with mCRPC (NCT05413850), in patients with high-risk localized PC (NCT06066437, Nautilus Trial) and after external beam radiotherapy (NCT06105918).
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Affiliation(s)
- Alexander Wurzer
- Department of Nuclear Medicine, University Hospital rechts der Isar, Technical University of Munich, Ismaninger Straße 22, 81675, Munich, Germany.
| | - Francesco De Rose
- Department of Nuclear Medicine, University Hospital rechts der Isar, Technical University of Munich, Ismaninger Straße 22, 81675, Munich, Germany
| | - Sebastian Fischer
- Chair of Pharmaceutical Radiochemistry, Technical University of Munich, Garching, Germany
| | - Markus Schwaiger
- Department of Nuclear Medicine, University Hospital rechts der Isar, Technical University of Munich, Ismaninger Straße 22, 81675, Munich, Germany
| | - Wolfgang Weber
- Department of Nuclear Medicine, University Hospital rechts der Isar, Technical University of Munich, Ismaninger Straße 22, 81675, Munich, Germany
| | - Stephan Nekolla
- Department of Nuclear Medicine, University Hospital rechts der Isar, Technical University of Munich, Ismaninger Straße 22, 81675, Munich, Germany
| | - Hans-Jürgen Wester
- Chair of Pharmaceutical Radiochemistry, Technical University of Munich, Garching, Germany
| | - Matthias Eiber
- Department of Nuclear Medicine, University Hospital rechts der Isar, Technical University of Munich, Ismaninger Straße 22, 81675, Munich, Germany
| | - Calogero D'Alessandria
- Department of Nuclear Medicine, University Hospital rechts der Isar, Technical University of Munich, Ismaninger Straße 22, 81675, Munich, Germany
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Li D, Ding L, Chen Y, Wang Z, Zeng Z, Ma X, Huang H, Li H, Qian X, Yang Z, Zhu H. Exploration of radionuclide labeling of a novel scFv-Fc fusion protein targeting CLDN18.2 for tumor diagnosis and treatment. Eur J Med Chem 2024; 266:116134. [PMID: 38266552 DOI: 10.1016/j.ejmech.2024.116134] [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: 12/01/2023] [Revised: 01/04/2024] [Accepted: 01/07/2024] [Indexed: 01/26/2024]
Abstract
PURPOSE Claudin 18.2 (CLDN18.2), due to its highly selective expression in tumor cells, has made breakthrough progress in clinical research and is expected to be integrated into routine tumor diagnosis and treatment. METHODS In this research, we obtained an scFv-Fc fusion protein (SF106) targeting CLDN18.2 through hybridoma technology. The scFv-Fc fusion protein was labeled with radioactive isotopes (124I and 177Lu) to generate the radio-probes. The targeting and specificity of the radio-probes were tested in cellular models, and its diagnostic and therapeutic potential was further evaluated in tumor-bearing models. RESULTS The molecular probes [124I]I-SF106 and [177Lu]Lu-DOTA-SF106 possess high radiochemical purity (RCP, 98.18 ± 0.93 % and 97.05 ± 1.1 %) and exhibit good stability in phosphate buffer saline and 5 % human serum albumin (92.44 ± 4.68 % and 91.03 ± 2.42 % at 120 h). [124I]I-SF106 uptake in cells expressing CLDN18.2 was well targeted and specific, and the dissociation constant was 17.74 nM [124I]I-SF106 micro-PET imaging showed that the maximum standardized uptake value (SUVmax) was significantly higher than CLDN18.2-negative tumors (1.83 ± 0.02 vs. 1.23 ± 0.04, p < 0.001). The maximum uptake was attained in tumors expressing CLDN18.2 at 48 h after injection. [124I]I-SF106 and [177Lu]Lu-DOTA-SF106 dosimetric study showed that the effective dose in humans complies with the medical safety standards required for their clinical application. The results of treatment experiments showed that 3 MBq of [177Lu]Lu-DOTA-SF106 in CLDN18.2-expressing tumor-bearing mice could significantly inhibit tumor growth. CONCLUSION These results indicate that radionuclide-labeled scFv-Fc molecular probes ([124I]I-SF106 and [177Lu]Lu-DOTA-SF106) provide a new possibility for the diagnosis and treatment of CLDN18.2-positive cancer patients in clinical practice.
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Affiliation(s)
- Dapeng Li
- Medical College, Guizhou University, Guiyang, 550025, Guizhou, China; Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), NMPA Key Laboratory for Research and Evaluation of Radiopharmaceuticals (National Medical Products Administration), Department of Nuclear Medicine, Peking University Cancer Hospital & Institute, Beijing, 100142, China
| | - Lei Ding
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Anesthesiology, Peking University Cancer Hospital & Institute, Beijing, 100142, China
| | - Yan Chen
- Medical College, Guizhou University, Guiyang, 550025, Guizhou, China; Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), NMPA Key Laboratory for Research and Evaluation of Radiopharmaceuticals (National Medical Products Administration), Department of Nuclear Medicine, Peking University Cancer Hospital & Institute, Beijing, 100142, China
| | - Zilei Wang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), NMPA Key Laboratory for Research and Evaluation of Radiopharmaceuticals (National Medical Products Administration), Department of Nuclear Medicine, Peking University Cancer Hospital & Institute, Beijing, 100142, China; Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Southwest Medical University, Luzhou, 646000, China
| | - Ziqing Zeng
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), NMPA Key Laboratory for Research and Evaluation of Radiopharmaceuticals (National Medical Products Administration), Department of Nuclear Medicine, Peking University Cancer Hospital & Institute, Beijing, 100142, China
| | - Xiaopan Ma
- Medical College, Guizhou University, Guiyang, 550025, Guizhou, China; Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), NMPA Key Laboratory for Research and Evaluation of Radiopharmaceuticals (National Medical Products Administration), Department of Nuclear Medicine, Peking University Cancer Hospital & Institute, Beijing, 100142, China
| | - Haifeng Huang
- Department of Orthopedics, Guizhou Provincial People's Hospital, Guiyang, 550025, Guizhou, China
| | - Hongjun Li
- Suzhou Transcenta Therapeutics Co., Ltd, Suzhou, 215000, China
| | - Xueming Qian
- Suzhou Transcenta Therapeutics Co., Ltd, Suzhou, 215000, China.
| | - Zhi Yang
- Medical College, Guizhou University, Guiyang, 550025, Guizhou, China; Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), NMPA Key Laboratory for Research and Evaluation of Radiopharmaceuticals (National Medical Products Administration), Department of Nuclear Medicine, Peking University Cancer Hospital & Institute, Beijing, 100142, China.
| | - Hua Zhu
- Medical College, Guizhou University, Guiyang, 550025, Guizhou, China; Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), NMPA Key Laboratory for Research and Evaluation of Radiopharmaceuticals (National Medical Products Administration), Department of Nuclear Medicine, Peking University Cancer Hospital & Institute, Beijing, 100142, China.
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5
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Rinscheid A, Gäble A, Wienand G, Pfob C, Dierks A, Kircher M, Trepel M, Weckermann D, Lapa C, Bundschuh RA. An Intrapatient Dosimetry Comparison of 177Lu-rhPSMA-10.1 and 177Lu-PSMA-I&T in Patients with Metastatic Castration-Resistant Prostate Cancer. J Nucl Med 2023; 64:1918-1924. [PMID: 37770108 DOI: 10.2967/jnumed.123.265970] [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: 05/02/2023] [Revised: 09/07/2023] [Indexed: 10/03/2023] Open
Abstract
As the use of radioligand therapy moves earlier in the prostate cancer timeline, minimizing the absorbed dose to normal organs while maintaining high tumor radiation doses becomes more clinically important because of the longer life expectancy of patients. We performed an intrapatient comparison of pretherapeutic dosimetry with the novel radiohybrid prostate-specific membrane antigen-targeting radiopharmaceutical 177Lu-rhPSMA-10.1, along with 177Lu-PSMA-I&T, in patients with metastatic castration-resistant prostate cancer. Methods: Four consecutive patients with advanced histologically proven metastatic castration-resistant prostate cancer who were scheduled for radioligand therapy were evaluated. Before undergoing therapy, each patient received 1.06 ± 0.05 GBq of 177Lu-rhPSMA-10.1 and 1.09 ± 0.02 GBq of 177Lu-PSMA-I&T at least 7 d apart. For dosimetric assessment, whole-body planar scintigraphy was performed after 5 min, 4 h, 1 d, 2 d, and 7 d. In addition, SPECT/CT images were acquired over the thorax and the abdomen, 4 h, 1 d, 2 d, and 7 d after injection. Dosimetry of the whole body and salivary glands was based on the evaluation of the counts in whole-body planar imaging. Dosimetry of the kidneys, liver, spleen, bone marrow, and tumor lesions (≤4 per patient) was based on the activity in volumes drawn on SPECT/CT images. Doses were calculated using OLINDA/EXM version 1.0. The therapeutic index (TI), or ratio between mean dose of the metastases and mean dose of the kidneys, was calculated for each patient. Results: We found the dose to the kidneys to be higher with 177Lu-rhPSMA-10.1 than with 177Lu-PSMA-I&T (0.68 ± 0.30 vs. 0.46 ± 0.10 mGy/MBq); however, 177Lu-rhPSMA-10.1 delivered an average of a 3.3 times (range, 1.2-8.3 times) higher absorbed radiation dose to individual tumor lesions. Consequently, intraindividual comparison revealed a 1.1-3.1 times higher TI for 177Lu-rhPSMA-10.1 than for 177Lu-PSMA-I&T in all evaluated patients. The effective whole-body dose was 0.038 ± 0.008 mSv/MBq for 177Lu-rhPSMA-10.1 and 0.022 ± 0.005 mSv/MBq for 177Lu-PSMA-I&T. Conclusion: Using 177Lu-rhPSMA-10.1 can significantly increase the tumor-absorbed dose and improve the TI compared with 177Lu-PSMA-I&T. An improved TI gives the flexibility to maximize tumor-absorbed doses up to a predefined renal dose limit or, in earlier disease, to reduce the radiation exposure to the kidney while still achieving an effective tumor dose. The function of at-risk organs such as the kidneys is being assessed in a prospective clinical trial.
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Affiliation(s)
- Andreas Rinscheid
- Department of Medical Physics and Radiation Protection, University Hospital Augsburg, Augsburg, Germany
| | - Alexander Gäble
- Department of Nuclear Medicine, Faculty of Medicine, University of Augsburg, Augsburg, Germany
| | - Georgine Wienand
- Department of Nuclear Medicine, Faculty of Medicine, University of Augsburg, Augsburg, Germany
| | - Christian Pfob
- Department of Nuclear Medicine, Faculty of Medicine, University of Augsburg, Augsburg, Germany
| | - Alexander Dierks
- Department of Nuclear Medicine, Faculty of Medicine, University of Augsburg, Augsburg, Germany
| | - Malte Kircher
- Department of Nuclear Medicine, Faculty of Medicine, University of Augsburg, Augsburg, Germany
| | - Martin Trepel
- Division of Oncology, Department of Internal Medicine, Faculty of Medicine, University of Augsburg, Augsburg, Germany; and
| | - Dorothea Weckermann
- Department of Urology, Faculty of Medicine, University of Augsburg, Augsburg, Germany
| | - Constantin Lapa
- Department of Nuclear Medicine, Faculty of Medicine, University of Augsburg, Augsburg, Germany;
| | - Ralph A Bundschuh
- Department of Nuclear Medicine, Faculty of Medicine, University of Augsburg, Augsburg, Germany
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Alati S, Singh R, Pomper MG, Rowe SP, Banerjee SR. Preclinical Development in Radiopharmaceutical Therapy for Prostate Cancer. Semin Nucl Med 2023; 53:663-686. [PMID: 37468417 DOI: 10.1053/j.semnuclmed.2023.06.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 06/19/2023] [Accepted: 06/21/2023] [Indexed: 07/21/2023]
Abstract
Prostate cancer is a leading cause of cancer death in men worldwide. Among the various treatment options, radiopharmaceutical therapy has shown notable success in metastatic, castration-resistant disease. Radiopharmaceutical therapy is a systemic approach that delivers cytotoxic radiation doses precisely to the malignant tumors and/or tumor microenvironment. Therapeutic radiopharmaceuticals are composed of a therapeutic radionuclide and a high-affinity, tumor-targeting carrier molecule. Therapeutic radionuclides used in preclinical prostate cancer studies are primarily α-, β--, or Auger-electron-emitting radiometals or radiohalogens. Monoclonal antibodies, antibody-derived fragments, peptides, and small molecules are frequently used as tumor-targeting molecules. Over the years, several important membrane-associated proteases and receptors have been identified, validated, and subsequently used for preclinical radiotherapeutic development for prostate cancer. Prostate-specific membrane antigen (PSMA) is the most well-studied prostate cancer-associated protease in preclinical literature. PSMA-targeting radiotherapeutic agents are being investigated using high-affinity antibody- and small-molecule-based agents for safety and efficacy. Early generations of such agents were developed simply by replacing radionuclides of the imaging agents with therapeutic ones. Later, extensive structure-activity relationship studies were conducted to address the safety and efficacy issues obtained from initial patient data. Recent regulatory approval of the 177Lu-labeled low-molecular-weight agent, 177Lu-PSMA-617, is a significant accomplishment. Current preclinical experiments are focused on the structural modification of 177Lu-PSMA-617 and relevant investigational agents to increase tumor targeting and reduce off-target binding and toxicity in healthy organs. While lutetium-177 (177Lu) remains the most widely used radionuclide, radiolabeled analogs with iodine-131 (128I), yttrium-90 (89Y), copper-67 (67Cu), and terbium-161 (161Tb) have been evaluated as potential alternatives in recent years. In addition, agents carrying the α-particle-emitting radiohalogen, astatine-211 (211At), or radiometals, actinium-225 (225Ac), lead-212 (212Pb), radium-223 (223Ra), and thorium-227 (227Th), have been increasingly investigated in preclinical research. Besides PSMA-based radiotherapeutics, other prominent prostate cancer-related proteases, for example, human kallikrein peptidases (HK2 and HK3), have been explored using monoclonal-antibody-(mAb)-based targeting platforms. Several promising mAbs targeting receptors overexpressed on the different stages of prostate cancer have also been developed for radiopharmaceutical therapy, for example, Delta-like ligand 3 (DLL-3), CD46, and CUB domain-containing protein 1 (CDCP1). Progress is also being made using peptide-based targeting platforms for the gastrin-releasing peptide receptor (GRPR), a well-established membrane-associated receptor expressed in localized and metastatic prostate cancers. Furthermore, mechanism-driven combination therapies appear to be a burgeoning area in the context of preclinical prostate cancer radiotherapeutics. Here, we review the current developments related to the preclinical radiopharmaceutical therapy of prostate cancer. These are summarized in two major topics: (1) therapeutic radionuclides and (2) tumor-targeting approaches using monoclonal antibodies, small molecules, and peptides.
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Affiliation(s)
- Suresh Alati
- Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD; Sidney Kimmel Comprehensive Cancer Center, Baltimore, MD
| | - Rajan Singh
- Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD; Sidney Kimmel Comprehensive Cancer Center, Baltimore, MD
| | - Martin G Pomper
- Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD; Sidney Kimmel Comprehensive Cancer Center, Baltimore, MD
| | - Steven P Rowe
- Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD; Sidney Kimmel Comprehensive Cancer Center, Baltimore, MD
| | - Sangeeta Ray Banerjee
- Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD; Sidney Kimmel Comprehensive Cancer Center, Baltimore, MD.
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7
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Delker A, Schleske M, Liubchenko G, Berg I, Zacherl MJ, Brendel M, Gildehaus FJ, Rumiantcev M, Resch S, Hürkamp K, Wenter V, Unterrainer LM, Bartenstein P, Ziegler SI, Beyer L, Böning G. Biodistribution and dosimetry for combined [ 177Lu]Lu-PSMA-I&T/[ 225Ac]Ac-PSMA-I&T therapy using multi-isotope quantitative SPECT imaging. Eur J Nucl Med Mol Imaging 2023; 50:1280-1290. [PMID: 36629878 PMCID: PMC10027798 DOI: 10.1007/s00259-022-06092-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 12/22/2022] [Indexed: 01/12/2023]
Abstract
PURPOSE Quantitative SPECT for patient-specific dosimetry is a valuable tool in the scope of radionuclide therapy, although its clinical application for 225Ac-based treatments may be limited due to low therapeutic activities. Therefore, the aim of this study was to demonstrate the feasibility of clinical quantitative low-count SPECT imaging during [177Lu]Lu-PSMA-I&T/[225Ac]Ac-PSMA-I&T treatment. METHODS Eight prostate cancer patients (1000 MBq/8 MBq [177Lu]Lu-PSMA-I&T/[225Ac]Ac-PSMA-I&T) received a single-bed quantitative 177Lu/225Ac SPECT/CT acquisition (1 h) at 24 h post treatment (high-energy collimator, 16 projections p. head à 3.5 min, 128 × 128 pixel). The gamma peak at 440 keV (width: 10%) of the progeny 213Bi was imaged along with the peak at 208 keV (width: 15%) of 177Lu. Quantification included CT-based attenuation and window-based scatter correction plus resolution modelling. Gaussian post-filtering with a full-width-half-maximum of 30 mm and 40-45 mm was employed to match the signal-to-noise ratio of 225Ac and 177Lu, respectively. RESULTS Kidney (r = 0.96, p < 0.01) and lesion (r = 0.94, p < 0.01) SUV for [177Lu]Lu-PSMA-I&T and [225Ac]Ac-PSMA-I&T showed a strong and significant correlation. Kidney SUV were significantly higher (p < 0.01) for [225Ac]Ac-PSMA-I&T (2.5 ± 0.8 vs. 2.1 ± 0.9), while for [177Lu]Lu-PSMA-I&T lesion SUV were significantly higher (p = 0.03; 1.8 ± 1.1 vs. 2.1 ± 1.5). For absorbed dose estimates, significant differences regarding the kidneys remained, while no significant differences for lesion dosimetry were found. CONCLUSION Quantitative low-count SPECT imaging of the peak at 440 keV during [225Ac]Ac-PSMA-I&T therapy is feasible. Multi-isotope imaging for [177Lu]Lu-PSMA-I&T/[225Ac]Ac-PSMA-I&T therapy indicates accumulation of free 213Bi in the kidneys.
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Affiliation(s)
- Astrid Delker
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany.
| | - Mirjam Schleske
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Grigory Liubchenko
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Isabella Berg
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | | | - Matthias Brendel
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
- SyNergy, University of Munich, Munich, Germany
- DZNE - German Center for Neurodegenerative Diseases, Munich, Germany
| | | | - Mikhail Rumiantcev
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Sandra Resch
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Kerstin Hürkamp
- Institute of Radiation Medicine, Helmholtz Zentrum München, German Research Center for Environmental Health GmbH, 85764, Neuherberg, Germany
| | - Vera Wenter
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Lena M Unterrainer
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Peter Bartenstein
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Sibylle I Ziegler
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Leonie Beyer
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Guido Böning
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
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8
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Holzleitner N, Günther T, Beck R, Lapa C, Wester HJ. Introduction of a SiFA Moiety into the D-Glutamate Chain of DOTA-PP-F11N Results in Radiohybrid-Based CCK-2R-Targeted Compounds with Improved Pharmacokinetics In Vivo. Pharmaceuticals (Basel) 2022; 15:ph15121467. [PMID: 36558917 PMCID: PMC9783573 DOI: 10.3390/ph15121467] [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: 11/07/2022] [Revised: 11/23/2022] [Accepted: 11/24/2022] [Indexed: 11/29/2022] Open
Abstract
In order to enable 18F- and 177Lu-labelling within the same molecule, we introduced a silicon-based fluoride acceptor (SiFA) into the hexa-D-glutamate chain of DOTA-PP-F11N. In addition, minigastrin analogues with a prolonged as well as γ-linked D-glutamate chain were synthesised and evaluated. CCK-2R affinity (IC50, AR42J cells) and lipophilicity (logD7.4) were determined. Biodistribution studies at 24 h post-injection (p.i.) and µSPECT/CT imaging at 1, 4 and 24 h p.i. were carried out in AR42J tumour-bearing CB17-SCID mice. CCK-2R affinity of (R)-DOTAGA-rhCCK-1 to 18 was enhanced with increasing distance between the SiFA building block and the binding motif. Lipophilicity of [177Lu]Lu-(R)-DOTAGA-rhCCK-1 to 18 was higher compared to that of [177Lu]Lu-DOTA-PP-F11N and [177Lu]Lu-CP04. The respective α- and γ-linked rhCCK derivatives revealing the highest CCK-2R affinity were further evaluated in vivo. In comparison with [177Lu]Lu-DOTA-PP-F11N, [177Lu-]Lu-(R)-DOTAGA-rhCCK-9 and -16 exhibited three- to eight-fold increased activity levels in the tumour at 24 h p.i. However, activity levels in the kidneys were elevated as well. We could show that the introduction of a lipophilic SiFA moiety into the hydrophilic backbone of [177Lu]Lu-DOTA-PP-F11N led to a decelerated blood clearance and thus improved tumour retention. However, elevated kidney retention has to be addressed in future studies.
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Affiliation(s)
- Nadine Holzleitner
- Pharmaceutical Radiochemistry, Technical University of Munich, 85748 Garching, Germany
- Correspondence: (N.H.); (T.G.)
| | - Thomas Günther
- Pharmaceutical Radiochemistry, Technical University of Munich, 85748 Garching, Germany
- Correspondence: (N.H.); (T.G.)
| | - Roswitha Beck
- Pharmaceutical Radiochemistry, Technical University of Munich, 85748 Garching, Germany
| | - Constantin Lapa
- Nuclear Medicine, Faculty of Medicine, University of Augsburg, 86156 Augsburg, Germany
| | - Hans-Jürgen Wester
- Pharmaceutical Radiochemistry, Technical University of Munich, 85748 Garching, Germany
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9
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Albumin-Mediated Size Exclusion Chromatography: The Apparent Molecular Weight of PSMA Radioligands as Novel Parameter to Estimate Their Blood Clearance Kinetics. Pharmaceuticals (Basel) 2022; 15:ph15091161. [PMID: 36145382 PMCID: PMC9500755 DOI: 10.3390/ph15091161] [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: 08/11/2022] [Revised: 09/13/2022] [Accepted: 09/14/2022] [Indexed: 11/17/2022] Open
Abstract
A meticulously adjusted pharmacokinetic profile and especially fine-tuned blood clearance kinetics are key characteristics of therapeutic radiopharmaceuticals. We, therefore, aimed to develop a method that allowed the estimation of blood clearance kinetics in vitro. For this purpose, 177Lu-labeled PSMA radioligands were subjected to a SEC column with human serum albumin (HSA) dissolved in a mobile phase. The HSA-mediated retention time of each PSMA ligand generated by this novel 'albumin-mediated size exclusion chromatography' (AMSEC) was converted to a ligand-specific apparent molecular weight (MWapp), and a normalization accounting for unspecific interactions between individual radioligands and the SEC column matrix was applied. The resulting normalized MWapp,norm. could serve to estimate the blood clearance of renally excreted radioligands by means of their influence on the highly size-selective process of glomerular filtration (GF). Based on the correlation between MW and the glomerular sieving coefficients (GSCs) of a set of plasma proteins, GSCcalc values were calculated to assess the relative differences in the expected GF/blood clearance kinetics in vivo and to select lead candidates among the evaluated radioligands. Significant differences in the MWapp,norm. and GSCcalc values, even for stereoisomers, were found, indicating that AMSEC might be a valuable and high-resolution tool for the preclinical selection of therapeutic lead compounds for clinical translation.
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10
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dos Santos JC, Schäfer M, Bauder-Wüst U, Beijer B, Eder M, Leotta K, Kleist C, Meyer JP, Dilling TR, Lewis JS, Kratochwil C, Kopka K, Haberkorn U, Mier W. Refined Chelator Spacer Moieties Ameliorate the Pharmacokinetics of PSMA-617. Front Chem 2022; 10:898692. [PMID: 36017165 PMCID: PMC9396645 DOI: 10.3389/fchem.2022.898692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 06/15/2022] [Indexed: 11/13/2022] Open
Abstract
Prostate-specific membrane antigen (PSMA) binding tracers are promising agents for the targeting of prostate tumors. To further optimize the clinically established radiopharmaceutical PSMA-617, novel PSMA ligands for prostate cancer endoradiotherapy were developed. A series of PSMA binding tracers that comprise a benzyl group at the chelator moiety were obtained by solid-phase synthesis. The compounds were labeled with 68Ga or 177Lu. Competitive cell-binding assays and internalization assays were performed using the cell line C4-2, a subline of the PSMA positive cell line LNCaP (human lymph node carcinoma of the prostate). Positron emission tomography (PET) imaging and biodistribution studies were conducted in a C4-2 tumor bearing BALB/c nu/nu mouse model. All 68Ga-labeled ligands were stable in human serum over 2 h; 177Lu-CA030 was stable over 72 h. The PSMA ligands revealed inhibition potencies [Ki] (equilibrium inhibition constants) between 4.8 and 33.8 nM. The percentage of internalization of the injected activity/106 cells of 68Ga-CA028, 68Ga-CA029, and 68Ga-CA030 was 41.2 ± 2.7, 44.3 ± 3.9, and 53.8 ± 5.4, respectively; for the comparator 68Ga-PSMA-617, 15.5 ± 3.1 was determined. Small animal PET imaging of the compounds showed a high tumor-to-background contrast. Organ distribution studies revealed high specific uptake in the tumor, that is, approximately 34.4 ± 9.8% of injected dose per gram (%ID/g) at 1 h post injection for 68Ga-CA028. At 1 h p.i., 68Ga-CA028 and 68Ga-CA030 demonstrated lower kidney uptake than 68Ga-PSMA-617, but at later time points, kidney time–activity curves converge. In line with the preclinical data, first diagnostic PET imaging using 68Ga-CA028 and 68Ga-CA030 revealed high-contrast detection of bone and lymph node lesions in patients with metastatic prostate cancer. The novel PSMA ligands, in particular CA028 and CA030, are promising agents for targeting PSMA-positive tumor lesions as shown in the preclinical evaluation and in a first patient, respectively. Thus, clinical translation of 68Ga-CA028 and 68Ga/177Lu-CA030 for diagnostics and endoradiotherapy of prostate cancer in larger cohorts of patients is warranted.
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Affiliation(s)
| | - Martin Schäfer
- Research Group Molecular Biology of Systemic Radiotherapy, German Cancer Research Center, Heidelberg, Germany
| | - Ulrike Bauder-Wüst
- Research Group Molecular Biology of Systemic Radiotherapy, German Cancer Research Center, Heidelberg, Germany
| | - Barbro Beijer
- Department of Nuclear Medicine, Heidelberg University Hospital, Heidelberg, Germany
| | - Matthias Eder
- Department of Nuclear Medicine, Division of Radiopharmaceutical Development, University Medical Center, University of Freiburg, Freiburg, Germany
- German Cancer Consortium, Partner Site Freiburg, University Medical Center, Freiburg, Germany and German Cancer Research Center, Heidelberg, Germany
| | - Karin Leotta
- Clinical Cooperation Unit Nuclear Medicine, German Cancer Research Center, Heidelberg, Germany
| | - Christian Kleist
- Department of Nuclear Medicine, Heidelberg University Hospital, Heidelberg, Germany
| | - Jan-Philip Meyer
- Department of Radiology and the Program in Pharmacology, Memorial Sloan Kettering Cancer Center, New York, NY, United States
| | - Thomas R. Dilling
- Department of Radiology and the Program in Pharmacology, Memorial Sloan Kettering Cancer Center, New York, NY, United States
| | - Jason S. Lewis
- Department of Radiology and the Program in Pharmacology, Memorial Sloan Kettering Cancer Center, New York, NY, United States
| | - Clemens Kratochwil
- Department of Nuclear Medicine, Heidelberg University Hospital, Heidelberg, Germany
| | - Klaus Kopka
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
| | - Uwe Haberkorn
- Department of Nuclear Medicine, Heidelberg University Hospital, Heidelberg, Germany
- Clinical Cooperation Unit Nuclear Medicine, German Cancer Research Center, Heidelberg, Germany
| | - Walter Mier
- Department of Nuclear Medicine, Heidelberg University Hospital, Heidelberg, Germany
- *Correspondence: Walter Mier,
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11
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Feuerecker B, Chantadisai M, Allmann A, Tauber R, Allmann J, Steinhelfer L, Rauscher I, Wurzer A, Wester HJ, Weber WA, d'Alessandria C, Eiber M. Pretherapeutic Comparative Dosimetry of 177Lu-rhPSMA-7.3 and 177Lu-PSMA I&T in Patients with Metastatic Castration-Resistant Prostate Cancer. J Nucl Med 2022; 63:833-839. [PMID: 34531260 PMCID: PMC9157737 DOI: 10.2967/jnumed.121.262671] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 08/26/2021] [Indexed: 11/16/2022] Open
Abstract
Radiohybrid prostate-specific membrane antigen (rhPSMA) ligands allow for labeling with 18F and radiometals for endoradiotherapy. rhPSMA-7.3 has been designated as a lead compound with promising preclinical data for 177Lu-rhPSMA-7.3, which has shown higher tumor uptake than 177Lu-PSMA I&T. In this retrospective analysis, we compared pretherapeutic clinical dosimetry data of both PSMA ligands. Methods: Six patients with metastatic castration-resistant prostate cancer underwent both 177Lu-rhPSMA-7.3 and 177Lu-PSMA I&T pretherapeutic dosimetry. Whole-body scintigraphy was performed at 1 h, 4 h, 24 h, 48 h, and 7 d after injection. Regions of interest covering the whole body, organs, bone marrow, and tumor lesions were drawn for each patient. Absorbed doses for individual patients and pretherapeutic applications were calculated using OLINDA/EXM. To facilitate the comparison of both ligands, we introduced the therapeutic index (TI), defined as the ratio of mean pretherapeutic doses to tumor lesions over relevant organs at risk. Results: Mean whole-body pretherapeutic effective doses for 177Lu-rhPSMA-7.3 and 177Lu-PSMA I&T were 0.12 ± 0.07 and 0.05 ± 0.03 Sv/GBq, respectively. Mean absorbed organ doses for 177Lu-rhPSMA-7.3 and 177Lu-PSMA I&T were, for example, 1.65 ± 0.28 and 0.73 ± 0.18 Gy/GBq for the kidneys, 0.19 ± 0.09 and 0.07 ± 0.03 Gy/GBq for the liver, 2.35 ± 0.78 and 0.80 ± 0.41 Gy/GBq for the parotid gland, and 0.67 ± 0.62 and 0.30 ± 0.27 Gy/GBq for the bone marrow, respectively. Tumor lesions received mean absorbed doses of 177Lu-rhPSMA-7.3 and 177Lu-PSMA I&T of 6.44 ± 6.44 and 2.64 ± 2.24 Gy/GBq, respectively. The mean TIs for the kidneys were 3.7 ± 2.2 and 3.6 ± 2.2 for 177Lu-rhPSMA-7.3 and 177Lu-PSMA I&T, respectively, and those for the bone marrow were 15.2 ± 10.2 and 15.1 ± 10.2 for 177Lu-rhPSMA-7.3 and 177Lu-PSMA I&T, respectively. Conclusion: Pretherapeutic clinical dosimetry confirmed preclinical results of mean absorbed doses for tumors that were 2-3 times higher for 177Lu-rhPSMA-7.3 than for 177Lu-PSMA I&T. Absorbed doses to normal organs also tended to be higher for 177Lu-rhPSMA-7.3, resulting overall in similar average TIs for both radiopharmaceuticals with considerable interpatient variability. 177Lu-rhPSMA-7.3 has promise for a therapeutic efficacy similar to that of 177Lu-PSMA I&T at smaller amounts of injected activity, simplifying radiation safety measurements (especially for large patient numbers or dose escalation regimens).
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Affiliation(s)
- Benedikt Feuerecker
- Department of Nuclear Medicine, School of Medicine, Technical University of Munich, München, Germany;
- Partnersite München, German Cancer Consortium (DKTK), Heidelberg, Germany
- Department of Radiology, School of Medicine, Technical University of Munich, München, Germany
| | - Maythinee Chantadisai
- Department of Nuclear Medicine, School of Medicine, Technical University of Munich, München, Germany
| | - Anne Allmann
- Department of Nuclear Medicine, School of Medicine, Technical University of Munich, München, Germany
| | - Robert Tauber
- Department of Urology, School of Medicine, Technical University of Munich, München, Germany; and
| | - Jakob Allmann
- Department of Nuclear Medicine, School of Medicine, Technical University of Munich, München, Germany
| | - Lisa Steinhelfer
- Department of Nuclear Medicine, School of Medicine, Technical University of Munich, München, Germany
| | - Isabel Rauscher
- Department of Nuclear Medicine, School of Medicine, Technical University of Munich, München, Germany
| | - Alexander Wurzer
- Department of Pharmaceutical Radiochemistry, Technical University of Munich, Garching, Germany
| | - Hans-Jürgen Wester
- Department of Pharmaceutical Radiochemistry, Technical University of Munich, Garching, Germany
| | - Wolfgang A Weber
- Department of Nuclear Medicine, School of Medicine, Technical University of Munich, München, Germany
- Partnersite München, German Cancer Consortium (DKTK), Heidelberg, Germany
| | - Calogero d'Alessandria
- Department of Nuclear Medicine, School of Medicine, Technical University of Munich, München, Germany
| | - Matthias Eiber
- Department of Nuclear Medicine, School of Medicine, Technical University of Munich, München, Germany
- Partnersite München, German Cancer Consortium (DKTK), Heidelberg, Germany
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12
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Gafita A, Marcus C, Kostos L, Schuster DM, Calais J, Hofman MS. Predictors and Real-World Use of Prostate-Specific Radioligand Therapy: PSMA and Beyond. Am Soc Clin Oncol Educ Book 2022; 42:1-17. [PMID: 35609224 DOI: 10.1200/edbk_350946] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
PSMA is a transmembrane protein that is markedly overexpressed in prostate cancer, making it an excellent target for imaging and treating patients with prostate cancer. Several small molecule inhibitors and antibodies of PSMA have been radiolabeled for use as therapeutic agents and are currently under clinical investigation. PSMA-based radionuclide therapy is a promising therapeutic option for men with metastatic prostate cancer. The phase II TheraP study demonstrated superior efficacy, lower side effects, and improved patient-reported outcomes compared with cabazitaxel. The phase III VISION study demonstrated that radionuclide therapy with β-emitter 177Lu-PSMA-617 can prolong survival and improve quality of life when offered in addition to standard-of-care therapy in men with PSMA-positive metastatic castration-resistant prostate cancer whose disease had progressed with conventional treatments. Nevertheless, up to 30% of patients have inherent resistance to PSMA-based radionuclide therapy, and acquired resistance is inevitable. Hence, strategies to increase the efficacy of PSMA-based radionuclide therapy have been under clinical investigation. These include better patient selection; increased radiation damage delivery via dosimetry-based administered dose or use of α-emitters instead of β-emitters; or using combinatorial approaches to overcome radioresistance mechanisms (innate or acquired), such as with novel hormonal agents, PARP inhibitors, or immunotherapy.
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Affiliation(s)
- Andrei Gafita
- Ahmanson Translational Imaging Division, Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA
| | - Charles Marcus
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA
| | - Louise Kostos
- Medical Oncology, Peter MacCallum Cancer Centre, Melbourne, Australia
| | - David M Schuster
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA
| | - Jeremie Calais
- Ahmanson Translational Imaging Division, Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA
| | - Michael S Hofman
- Molecular Imaging and Therapeutic Nuclear Medicine, Cancer Imaging; Prostate Cancer Theranostics and Imaging Centre of Excellence, Peter MacCallum Cancer Centre, Melbourne, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Australia
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13
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18F- or 177Lu-labeled bivalent ligand of fibroblast activation protein with high tumor uptake and retention. Eur J Nucl Med Mol Imaging 2022; 49:2705-2715. [PMID: 35290473 DOI: 10.1007/s00259-022-05757-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 03/03/2022] [Indexed: 11/04/2022]
Abstract
PURPOSE Fibroblast activation protein (FAP) has become a promising cancer-related target for diagnosis and therapy. The aim of this study was to develop a bivalent FAP ligand for both diagnostic PET imaging and endoradiotherapy. METHODS We synthesized a bivalent FAP ligand (ND-bisFAP) and labeled it with 18F or 177Lu. FAP-positive A549-FAP cells were used to study competitive binding to FAP, cellular internalization, and efflux properties in vitro. Micro-PET imaging with [18F]AlF-ND-bisFAPI was conducted in mice bearing A549-FAP or U87MG tumors. Biodistribution and therapeutic efficacy of [177Lu]Lu-ND-bisFAPI were conducted in mice bearing A549-FAP tumors. RESULTS The FAP binding affinity of ND-bisFAPI is 0.25 ± 0.05 nM, eightfold higher in potency than the monomeric DOTA-FAPI-04 (IC50 = 2.0 ± 0.18 nM). In A549-FAP cells, ND-bisFAPI showed specific uptake, a high internalized fraction, and slow cellular efflux. Compared to the monomeric [18F]AlF-FAPI-42, micro-PET imaging with [18F]AlF-ND-bisFAPI showed higher specific tumor uptake and retention for at least 6 h. Biodistribution studies showed that [177Lu]Lu-ND-bisFAPI had higher tumor uptake than [177Lu]Lu-FAPI-04 at the 24, 72, 120, and 168 h time points (all P < 0.01). [177Lu]Lu-ND-bisFAPI delivered fourfold higher radiation than [177Lu]Lu-FAPI-04 to A549-FAP tumors. For the endoradiotherapy study, 37 MBq of [177Lu]Lu-ND-bisFAPI significantly reduced tumor growth compared to the same dose of [177Lu]Lu-FAPI-04. Half of the dose of [177Lu]Lu-ND-bisFAPI (18.5 MBq) has comparable median survival as 37 MBq of [177Lu]Lu-FAPI-04 (37 vs 36 days). CONCLUSION The novel bivalent FAP ligand was developed as a theranostic radiopharmaceutical and showed promising properties including higher tumor uptake and retention compared to the established radioligands [18F]AlF-FAPI-42 and [177Lu]Lu-FAPI-04. Preliminary experiments with 18F- or 177Lu-labeled ND-bisFAPI showed promising imaging properties and favorable anti-tumor responses.
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14
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Neels OC, Kopka K, Liolios C, Afshar-Oromieh A. Radiolabeled PSMA Inhibitors. Cancers (Basel) 2021; 13:6255. [PMID: 34944875 PMCID: PMC8699044 DOI: 10.3390/cancers13246255] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 12/10/2021] [Accepted: 12/11/2021] [Indexed: 12/16/2022] Open
Abstract
PSMA has shown to be a promising target for diagnosis and therapy (theranostics) of prostate cancer. We have reviewed developments in the field of radio- and fluorescence-guided surgery and targeted photodynamic therapy as well as multitargeting PSMA inhibitors also addressing albumin, GRPr and integrin αvβ3. An overview of the regulatory status of PSMA-targeting radiopharmaceuticals in the USA and Europe is also provided. Technical and quality aspects of PSMA-targeting radiopharmaceuticals are described and new emerging radiolabeling strategies are discussed. Furthermore, insights are given into the production, application and potential of alternatives beyond the commonly used radionuclides for radiolabeling PSMA inhibitors. An additional refinement of radiopharmaceuticals is required in order to further improve dose-limiting factors, such as nephrotoxicity and salivary gland uptake during endoradiotherapy. The improvement of patient treatment achieved by the advantageous combination of radionuclide therapy with alternative therapies is also a special focus of this review.
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Affiliation(s)
- Oliver C. Neels
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Bautzner Landstrasse 400, 01328 Dresden, Germany;
| | - Klaus Kopka
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Bautzner Landstrasse 400, 01328 Dresden, Germany;
- Faculty of Chemistry and Food Chemistry, School of Science, Technical University Dresden, Mommsenstrasse 4, 01062 Dresden, Germany
| | - Christos Liolios
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, National & Kapodistrian University of Athens, Zografou, 15771 Athens, Greece;
- INRASTES, Radiochemistry Laboratory, NCSR “Demokritos”, Ag. Paraskevi Attikis, 15310 Athens, Greece
| | - Ali Afshar-Oromieh
- Department of Nuclear Medicine, Bern University Hospital (Inselspital), Freiburgstrasse 18, 3010 Bern, Switzerland;
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