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Deiser S, Fenzl S, König V, Drexler M, Smith LM, George ME, Beck R, Witney TH, Inoue S, Casini A. (SiFA)SeFe: A Hydrophilic Silicon-Based Fluoride Acceptor Enabling Versatile Peptidic Radiohybrid Tracers. J Med Chem 2024; 67:14077-14094. [PMID: 39115131 PMCID: PMC11345769 DOI: 10.1021/acs.jmedchem.4c00924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Revised: 07/24/2024] [Accepted: 07/26/2024] [Indexed: 08/23/2024]
Abstract
The radiohybrid (rh) concept to design targeted (and chemically identical) radiotracers for imaging or radionuclide therapy of tumors has gained momentum. For this strategy, a new bifunctional Silicon-based Fluoride Acceptor (SiFA) moiety (SiFA)SeFe was synthesized, endowed with improved hydrophilicity and high versatility of integration into rh-compounds. Preliminary radiolabeling and stability studies under different conditions were conducted using model bioconjugate peptides. Further, three somatostatin receptor 2 (sstR2)-targeted rh-compounds ((SiFA)SeFe-rhTATE1-3, TATE = (Tyr3)-octreotate) were developed. Compound (SiFA)SeFe-rhTATE3, enables labeling with 18F for PET imaging or chelation of 177Lu for therapy. The rh-compounds possess comparable receptor binding affinity and in vitro performance as good as the clinically proven gold standards. SstR2-specificity was further shown for (SiFA)SeFe-rhTATE2 using the chicken chorioallantoic membrane (CAM) model. The biodistribution of two compounds in mice showed high accumulation in tumors and excretion via the kidneys, demonstrating the clinical applicability of the (SiFA)SeFe moiety.
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Affiliation(s)
- Sandra Deiser
- Chair
of Medicinal and Bioinorganic Chemistry, Department of Chemistry,
School of Natural Sciences, Technical University
of Munich, Lichtenbergstr. 4, 85748 Garching b. München, Germany
- Chair
of Pharmaceutical Radiochemistry, Department of Chemistry, School
of Natural Sciences, Technical University
of Munich, Walther-Meißner-Str.
3, 85748 Garching
b. München, Germany
| | - Sebastian Fenzl
- Chair
of Pharmaceutical Radiochemistry, Department of Chemistry, School
of Natural Sciences, Technical University
of Munich, Walther-Meißner-Str.
3, 85748 Garching
b. München, Germany
- Institute
of Silicon Chemistry, Department of Chemistry, School of Natural Sciences, Technical University of Munich, Lichtenbergstr. 4, 85748 Garching b. München, Germany
| | - Victor König
- Chair
of Pharmaceutical Radiochemistry, Department of Chemistry, School
of Natural Sciences, Technical University
of Munich, Walther-Meißner-Str.
3, 85748 Garching
b. München, Germany
| | - Marike Drexler
- Chair
of Medicinal and Bioinorganic Chemistry, Department of Chemistry,
School of Natural Sciences, Technical University
of Munich, Lichtenbergstr. 4, 85748 Garching b. München, Germany
- Chair
of Pharmaceutical Radiochemistry, Department of Chemistry, School
of Natural Sciences, Technical University
of Munich, Walther-Meißner-Str.
3, 85748 Garching
b. München, Germany
| | - Lydia M. Smith
- School
of Biomedical Engineering and Imaging Sciences King’s College London St Thomas’ Hospital, London SE1 7EH, U.K.
| | - Madeleine E. George
- School
of Biomedical Engineering and Imaging Sciences King’s College London St Thomas’ Hospital, London SE1 7EH, U.K.
| | - Roswitha Beck
- Chair
of Pharmaceutical Radiochemistry, Department of Chemistry, School
of Natural Sciences, Technical University
of Munich, Walther-Meißner-Str.
3, 85748 Garching
b. München, Germany
| | - Timothy H. Witney
- School
of Biomedical Engineering and Imaging Sciences King’s College London St Thomas’ Hospital, London SE1 7EH, U.K.
| | - Shigeyoshi Inoue
- Institute
of Silicon Chemistry, Department of Chemistry, School of Natural Sciences, Technical University of Munich, Lichtenbergstr. 4, 85748 Garching b. München, Germany
| | - Angela Casini
- Chair
of Medicinal and Bioinorganic Chemistry, Department of Chemistry,
School of Natural Sciences, Technical University
of Munich, Lichtenbergstr. 4, 85748 Garching b. München, Germany
- Chair
of Pharmaceutical Radiochemistry, Department of Chemistry, School
of Natural Sciences, Technical University
of Munich, Walther-Meißner-Str.
3, 85748 Garching
b. München, Germany
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Ebrahimi F, Zargari NR, Akhlaghi M, Asghari SM, Abdi K, Balalaie S, Asadi M, Beiki D. Synthesis, Radiolabeling, and Biodistribution Study of a Novel DOTA-Peptide for Targeting Vascular Endothelial Growth Factor Receptors in the Molecular Imaging of Breast Cancer. Pharmaceutics 2024; 16:899. [PMID: 39065596 PMCID: PMC11279866 DOI: 10.3390/pharmaceutics16070899] [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: 11/22/2023] [Revised: 12/09/2023] [Accepted: 12/22/2023] [Indexed: 07/28/2024] Open
Abstract
As angiogenesis plays a pivotal role in tumor progression and metastasis, leading to more cancer-related deaths, the angiogenic process can be considered as a target for diagnostic and therapeutic applications. The vascular endothelial growth factor receptor-1 (VEGR-1) and VEGFR-2 have high expression on breast cancer cells and contribute to angiogenesis and tumor development. Thus, early diagnosis through VEGFR-1/2 detection is an excellent strategy that can significantly increase a patient's chance of survival. In this study, the VEGFR1/2-targeting peptide VGB3 was conjugated with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA), using 6-aminohexanoic acid (Ahx) as a spacer to prevent steric hindrance in binding. DOTA-Ahx-VGB3 was radiolabeled with Gallium-68 (68Ga) efficiently. An in vitro cell binding assay was assessed in the 4T1 cell line. The tumor-targeting potential of [68Ga]Ga-DOTA-Ahx-VGB3 was conducted for 4T1 tumor-bearing mice. Consequently, high radiochemical purity [68Ga]Ga-DOTA-Ahx-VGB3 (RCP = 98%) was prepared and stabilized in different buffer systems. Approximately 17% of the radiopeptide was internalized after 2 h incubation and receptor binding as characterized by the IC50 value being about 867 nM. The biodistribution and PET/CT studies revealed that [68Ga]Ga-DOTA-Ahx-VGB3 reached the tumor site and was excreted rapidly by the renal system. These features convey [68Ga]Ga-DOTA-Ahx-VGB3 as a suitable agent for the noninvasive visualization of VEGFR-1/2 expression.
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Affiliation(s)
- Fatemeh Ebrahimi
- Department of Nuclear Pharmacy, School of Pharmacy, Tehran University of Medical Sciences, Tehran 1417614411, Iran
| | | | - Mehdi Akhlaghi
- Research Center for Nuclear Medicine, Shariati Hospital, Tehran University of Medical Sciences, Tehran 1411713135, Iran;
| | - S. Mohsen Asghari
- Institute of Biochemistry and Biophysics (IBB), University of Tehran, Tehran 1417614335, Iran;
| | - Khosrou Abdi
- Department of Nuclear Pharmacy, School of Pharmacy, Tehran University of Medical Sciences, Tehran 1417614411, Iran
| | - Saeed Balalaie
- Peptide Chemistry Research Institute, K. N. Toosi University of Technology, Tehran 158754416, Iran
| | - Mahboobeh Asadi
- Research Center for Nuclear Medicine, Shariati Hospital, Tehran University of Medical Sciences, Tehran 1411713135, Iran;
| | - Davood Beiki
- Department of Nuclear Pharmacy, School of Pharmacy, Tehran University of Medical Sciences, Tehran 1417614411, Iran
- Research Center for Nuclear Medicine, Shariati Hospital, Tehran University of Medical Sciences, Tehran 1411713135, Iran;
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3
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Chapeau D, Beekman S, Handula M, Murce E, de Ridder C, Stuurman D, Seimbille Y. eTFC-01: a dual-labeled chelate-bridged tracer for SSTR2-positive tumors. EJNMMI Radiopharm Chem 2024; 9:44. [PMID: 38775990 PMCID: PMC11111636 DOI: 10.1186/s41181-024-00272-0] [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: 04/08/2024] [Accepted: 05/15/2024] [Indexed: 05/25/2024] Open
Abstract
BACKGROUND Integrating radioactive and optical imaging techniques can facilitate the prognosis and surgical guidance for cancer patients. Using a single dual-labeled tracer ensures consistency in both imaging modalities. However, developing such molecule is challenging due to the need to preserve the biochemical properties of the tracer while introducing bulky labeling moieties. In our study, we designed a trifunctional chelate that facilitates the coupling of the targeting vector and fluorescent dye at opposite sites to avoid undesired steric hindrance effects. The synthesis of the trifunctional chelate N3-Py-DOTAGA-(tBu)3 (7) involved a five-step synthetic route, followed by conjugation to the linear peptidyl-resin 8 through solid-phase synthesis. After deprotection and cyclization, the near-infrared fluorescent dye sulfo-Cy.5 was introduced using copper free click chemistry, resulting in eTFC-01. Subsequently, eTFC-01 was labeled with [111In]InCl3. In vitro assessments of eTFC-01 binding, uptake, and internalization were conducted in SSTR2-transfected U2OS cells. Ex-vivo biodistribution and fluorescence imaging were performed in H69-tumor bearing mice. RESULTS eTFC-01 demonstrated a two-fold higher IC50 value for SSTR2 compared to the gold standard DOTA-TATE. Labeling of eTFC-01 with [111In]InCl3 gave a high radiochemical yield and purity. The uptake of [111In]In-eTFC-01 in U2OS.SSTR2 cells was two-fold lower than the uptake of [111In]In-DOTA-TATE, consistent with the binding affinity. Tumor uptake in H69-xenografted mice was lower for [111In]In-eTFC-01 at all-time points compared to [111In]In-DOTA-TATE. Prolonged blood circulation led to increased accumulation of [111In]In-eTFC-01 in highly vascularized tissues, such as lungs, skin, and heart. Fluorescence measurements in different organs correlated with the radioactive signal distribution. CONCLUSION The successful synthesis and coupling of the trifunctional chelate to the peptide and fluorescent dye support the potential of this synthetic approach to generate dual labeled tracers. While promising in vitro, the in vivo results obtained with [111In]In-eTFC-01 suggest the need for adjustments to enhance tracer distribution.
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Affiliation(s)
- Dylan Chapeau
- Erasmus MC, Department of Radiology and Nuclear Medicine, University Medical Center Rotterdam, Rotterdam, The Netherlands
- Erasmus MC Cancer Institute, Rotterdam, The Netherlands
| | - Savanne Beekman
- Erasmus MC, Department of Radiology and Nuclear Medicine, University Medical Center Rotterdam, Rotterdam, The Netherlands
- Erasmus MC Cancer Institute, Rotterdam, The Netherlands
| | - Maryana Handula
- Erasmus MC, Department of Radiology and Nuclear Medicine, University Medical Center Rotterdam, Rotterdam, The Netherlands
- Erasmus MC Cancer Institute, Rotterdam, The Netherlands
| | - Erika Murce
- Erasmus MC, Department of Radiology and Nuclear Medicine, University Medical Center Rotterdam, Rotterdam, The Netherlands
- Erasmus MC Cancer Institute, Rotterdam, The Netherlands
| | - Corrina de Ridder
- Erasmus MC, Department of Radiology and Nuclear Medicine, University Medical Center Rotterdam, Rotterdam, The Netherlands
- Erasmus MC Cancer Institute, Rotterdam, The Netherlands
| | - Debra Stuurman
- Erasmus MC, Department of Radiology and Nuclear Medicine, University Medical Center Rotterdam, Rotterdam, The Netherlands
- Erasmus MC Cancer Institute, Rotterdam, The Netherlands
| | - Yann Seimbille
- Erasmus MC, Department of Radiology and Nuclear Medicine, University Medical Center Rotterdam, Rotterdam, The Netherlands.
- Erasmus MC Cancer Institute, Rotterdam, The Netherlands.
- TRIUMF, Life Sciences Division, Vancouver, Canada.
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Woods JJ, Cosby AG, Wacker JN, Aguirre Quintana LM, Peterson A, Minasian SG, Abergel RJ. Macrocyclic 1,2-Hydroxypyridinone-Based Chelators as Potential Ligands for Thorium-227 and Zirconium-89 Radiopharmaceuticals. Inorg Chem 2023; 62:20721-20732. [PMID: 37590371 DOI: 10.1021/acs.inorgchem.3c02164] [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: 08/19/2023]
Abstract
Thorium-227 (227Th) is an α-emitting radionuclide that has shown preclinical and clinical promise for use in targeted α-therapy (TAT), a type of molecular radiopharmaceutical treatment that harnesses high energy α particles to eradicate cancerous lesions. Despite these initial successes, there still exists a need for bifunctional chelators that can stably bind thorium in vivo. Toward this goal, we have prepared two macrocyclic chelators bearing 1,2-hydroxypyridinone groups. Both chelators can be synthesized in less than six steps from readily available starting materials, which is an advantage over currently available platforms. The complex formation constants (log βmlh) of these ligands with Zr4+ and Th4+, measured by spectrophotometric titrations, are greater than 34 for both chelators, indicating the formation of exceedingly stable complexes. Radiolabeling studies were performed to show that these ligands can bind [227Th]Th4+ at concentrations as low as 10-6 M, and serum stability experiments demonstrate the high kinetic stability of the formed complexes under biological conditions. Identical experiments with zirconium-89 (89Zr), a positron-emitting radioisotope used for positron emission tomography (PET) imaging, demonstrate that these chelators can also effectively bind Zr4+ with high thermodynamic and kinetic stability. Collectively, the data reported herein highlight the suitability of these ligands for use in 89Zr/227Th paired radioimmunotheranostics.
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Affiliation(s)
- Joshua J Woods
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Alexia G Cosby
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Jennifer N Wacker
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Luis M Aguirre Quintana
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Appie Peterson
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Stefan G Minasian
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Rebecca J Abergel
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Nuclear Engineering, University of California Berkeley, Berkeley, California 94720, United States
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5
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Han G, Hwang E, Lin F, Clift R, Kim D, Guest M, Bischoff E, Moran S, Li G. RYZ101 (Ac-225 DOTATATE) Opportunity beyond Gastroenteropancreatic Neuroendocrine Tumors: Preclinical Efficacy in Small-Cell Lung Cancer. Mol Cancer Ther 2023; 22:1434-1443. [PMID: 37616528 DOI: 10.1158/1535-7163.mct-23-0029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 04/28/2023] [Accepted: 08/21/2023] [Indexed: 08/26/2023]
Abstract
Overexpression of somatostatin receptors (SSTR), particularly SSTR2, is found in gastroenteropancreatic neuroendocrine tumors (GEP-NET), and subsets of other solid tumors such as small-cell lung cancer (SCLC). SCLC accounts for approximately 13% to 15% of lung cancer and lacks effective therapeutic options. IHC analysis indicates that up to 50% of SCLC tumors are SSTR2-positive, with a substantial subset showing high and homogenous expression. Peptide receptor radionuclide therapy with radiolabeled somatostatin analogue, Lu-177 DOTATATE, has been approved for GEP-NETs. Different strategies aimed at improving outcomes, such as the use of alpha-emitting radioisotopes, are currently being investigated. RYZ101 (Ac-225 DOTATATE) is comprised of the alpha-emitting radioisotope actinium-225, chemical chelator DOTA, and octreotate (TATE), a somatostatin analogue. In the cell-based competitive radioligand binding assay, RAYZ-10001-La (lanthanum surrogate for RYZ101) showed high binding affinity (Ki = 0.057 nmol/L) to human SSTR2 and >600-fold selectivity against other SSTR subtypes. RAYZ-10001-La exhibited efficient internalization to SSTR2-positive cells. In multiple SSTR2-expressing SCLC xenograft models, single-dose intravenous RYZ101 3 μCi (0.111 MBq) or 4 μCi (0.148 MBq) significantly inhibited tumor growth, with deeper responses, including sustained regression, observed in the models with higher SSTR2 levels. The antitumor effect was further enhanced when RYZ101 was combined with carboplatin and etoposide at clinically relevant doses. In summary, RYZ101 is a highly potent, alpha-emitting radiopharmaceutical agent, and preclinical data demonstrate the potential of RYZ101 for the treatment of patients with SSTR-positive cancers.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Gary Li
- RayzeBio, Inc., San Diego, California
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6
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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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7
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Chapeau D, Koustoulidou S, Handula M, Beekman S, de Ridder C, Stuurman D, de Blois E, Buchatskaya Y, van der Schilden K, de Jong M, Konijnenberg MW, Seimbille Y. [ 212Pb]Pb-eSOMA-01: A Promising Radioligand for Targeted Alpha Therapy of Neuroendocrine Tumors. Pharmaceuticals (Basel) 2023; 16:985. [PMID: 37513897 PMCID: PMC10384862 DOI: 10.3390/ph16070985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 07/03/2023] [Accepted: 07/06/2023] [Indexed: 07/30/2023] Open
Abstract
Peptide receptor radionuclide therapy (PRRT) has been applied to the treatment of neuroendocrine tumors (NETs) for over two decades. However, improvement is still needed, and targeted alpha therapy (TAT) with alpha emitters such as lead-212 (212Pb) represents a promising avenue. A series of ligands based on octreotate was developed. Lead-203 was used as an imaging surrogate for the selection of the best candidate for the studies with lead-212. 203/212Pb radiolabeling and in vitro assays were carried out, followed by SPECT/CT imaging and ex vivo biodistribution in NCI-H69 tumor-bearing mice. High radiochemical yields (≥99%) and purity (≥96%) were obtained for all ligands. [203Pb]Pb-eSOMA-01 and [203Pb]Pb-eSOMA-02 showed high stability in PBS and mouse serum up to 24 h, whereas [203Pb]Pb-eSOMA-03 was unstable in those conditions. All compounds exhibited a nanomolar affinity (2.5-3.1 nM) for SSTR2. SPECT/CT images revealed high tumor uptake at 1, 4, and 24 h post-injection of [203Pb]Pb-eSOMA-01/02. Ex vivo biodistribution studies confirmed that the highest uptake in tumors was observed with [212Pb]Pb-eSOMA-01. [212Pb]Pb-eESOMA-01 displayed the highest absorbed dose in the tumor (35.49 Gy/MBq) and the lowest absorbed dose in the kidneys (121.73 Gy/MBq) among the three tested radioligands. [212Pb]Pb-eSOMA-01 is a promising candidate for targeted alpha therapy of NETs. Further investigations are required to confirm its potential.
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Affiliation(s)
- Dylan Chapeau
- Erasmus MC, Department of Radiology and Nuclear Medicine, University Medical Center Rotterdam, 3015 GD Rotterdam, The Netherlands
- Erasmus MC Cancer Institute, 3015 GD Rotterdam, The Netherlands
| | - Sofia Koustoulidou
- Erasmus MC, Department of Radiology and Nuclear Medicine, University Medical Center Rotterdam, 3015 GD Rotterdam, The Netherlands
- Erasmus MC Cancer Institute, 3015 GD Rotterdam, The Netherlands
| | - Maryana Handula
- Erasmus MC, Department of Radiology and Nuclear Medicine, University Medical Center Rotterdam, 3015 GD Rotterdam, The Netherlands
- Erasmus MC Cancer Institute, 3015 GD Rotterdam, The Netherlands
| | - Savanne Beekman
- Erasmus MC, Department of Radiology and Nuclear Medicine, University Medical Center Rotterdam, 3015 GD Rotterdam, The Netherlands
- Erasmus MC Cancer Institute, 3015 GD Rotterdam, The Netherlands
| | - Corrina de Ridder
- Erasmus MC, Department of Radiology and Nuclear Medicine, University Medical Center Rotterdam, 3015 GD Rotterdam, The Netherlands
- Erasmus MC Cancer Institute, 3015 GD Rotterdam, The Netherlands
| | - Debra Stuurman
- Erasmus MC, Department of Radiology and Nuclear Medicine, University Medical Center Rotterdam, 3015 GD Rotterdam, The Netherlands
- Erasmus MC Cancer Institute, 3015 GD Rotterdam, The Netherlands
| | - Erik de Blois
- Erasmus MC, Department of Radiology and Nuclear Medicine, University Medical Center Rotterdam, 3015 GD Rotterdam, The Netherlands
- Erasmus MC Cancer Institute, 3015 GD Rotterdam, The Netherlands
| | - Yulia Buchatskaya
- Nuclear Research & Consultancy Group, 1755 LE Petten, The Netherlands
| | | | - Marion de Jong
- Erasmus MC, Department of Radiology and Nuclear Medicine, University Medical Center Rotterdam, 3015 GD Rotterdam, The Netherlands
- Erasmus MC Cancer Institute, 3015 GD Rotterdam, The Netherlands
| | - Mark W Konijnenberg
- Erasmus MC, Department of Radiology and Nuclear Medicine, University Medical Center Rotterdam, 3015 GD Rotterdam, The Netherlands
- Erasmus MC Cancer Institute, 3015 GD Rotterdam, The Netherlands
| | - Yann Seimbille
- Erasmus MC, Department of Radiology and Nuclear Medicine, University Medical Center Rotterdam, 3015 GD Rotterdam, The Netherlands
- Erasmus MC Cancer Institute, 3015 GD Rotterdam, The Netherlands
- TRIUMF, Life Sciences Division, Vancouver, BC V6T 2A3, Canada
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8
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Schollhammer R, Quintyn Ranty ML, de Clermont Gallerande H, Cavelier F, Valverde IE, Vimont D, Hindié E, Morgat C. Theranostics of Primary Prostate Cancer: Beyond PSMA and GRP-R. Cancers (Basel) 2023; 15:cancers15082345. [PMID: 37190273 DOI: 10.3390/cancers15082345] [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: 02/17/2023] [Revised: 04/07/2023] [Accepted: 04/13/2023] [Indexed: 05/17/2023] Open
Abstract
The imaging of Prostate-Specific Membrane Antigen (PSMA) is now widely used at the initial staging of prostate cancers in patients with a high metastatic risk. However, its ability to detect low-grade tumor lesions is not optimal. METHODS First, we prospectively performed neurotensin receptor-1 (NTS1) IHC in a series of patients receiving both [68Ga]Ga-PSMA-617 and [68Ga]Ga-RM2 before prostatectomy. In this series, PSMA and GRP-R IHC were also available (n = 16). Next, we aimed at confirming the PSMA/GRP-R/NTS1 expression profile by retrospective autoradiography (n = 46) using a specific radiopharmaceuticals study and also aimed to decipher the expression of less-investigated targets such as NTS2, SST2 and CXCR4. RESULTS In the IHC study, all samples with negative PSMA staining (two patients with ISUP 2 and one with ISUP 3) were strongly positive for NTS1 staining. No samples were negative for all three stains-for PSMA, GRP-R or NTS1. In the autoradiography study, binding of [111In]In-PSMA-617 was high in all ISUP groups. However, some samples did not bind or bound weakly to [111In]In-PSMA-617 (9%). In these cases, binding of [111n]In-JMV 6659 and [111In]In-JMV 7488 towards NTS1 and NTS2 was high. CONCLUSIONS Targeting PSMA and NTS1/NTS2 could allow for the detection of all intraprostatic lesions.
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Affiliation(s)
- Romain Schollhammer
- Nuclear Medicine Department, Bordeaux University Hospital, 33000 Bordeaux, France
- INCIA, University of Bordeaux, CNRS, EPHE, UMR 5287, 33000 Bordeaux, France
| | | | - Henri de Clermont Gallerande
- Nuclear Medicine Department, Bordeaux University Hospital, 33000 Bordeaux, France
- INCIA, University of Bordeaux, CNRS, EPHE, UMR 5287, 33000 Bordeaux, France
| | - Florine Cavelier
- Institut des Biomolécules Max Mousseron IBMM, UMR 5247, CNRS, Université Montpellier, ENSCM, Pôle Chimie Balard, 1919 Route de Mende, Cedex 5, 34293 Montpellier, France
| | - Ibai E Valverde
- Institut de Chimie Moléculaire de l'Université de Bourgogne, UMR 6302, CNRS, Université Bourgogne Franche-Comté, 9 Avenue Alain Savary, 21000 Dijon, France
| | - Delphine Vimont
- INCIA, University of Bordeaux, CNRS, EPHE, UMR 5287, 33000 Bordeaux, France
| | - Elif Hindié
- Nuclear Medicine Department, Bordeaux University Hospital, 33000 Bordeaux, France
- INCIA, University of Bordeaux, CNRS, EPHE, UMR 5287, 33000 Bordeaux, France
- Institut Universitaire de France (IUF), 75231 Paris, France
| | - Clément Morgat
- Nuclear Medicine Department, Bordeaux University Hospital, 33000 Bordeaux, France
- INCIA, University of Bordeaux, CNRS, EPHE, UMR 5287, 33000 Bordeaux, France
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9
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Siebinga H, de Wit-van der Veen BJ, Beijnen JH, Dorlo TPC, Huitema ADR, Hendrikx JJMA. A physiologically based pharmacokinetic model for [ 68Ga]Ga-(HA-)DOTATATE to predict whole-body distribution and tumor sink effects in GEP-NET patients. EJNMMI Res 2023; 13:8. [PMID: 36735114 PMCID: PMC9898489 DOI: 10.1186/s13550-023-00958-7] [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: 03/25/2022] [Accepted: 01/26/2023] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Little is known about parameters that have a relevant impact on (dis)similarities in biodistribution between various 68Ga-labeled somatostatin analogues. Additionally, the effect of tumor burden on organ uptake remains unclear. Therefore, the aim of this study was to describe and compare organ and tumor distribution of [68Ga]Ga-DOTATATE and [68Ga]Ga-HA-DOTATATE using a physiologically based pharmacokinetic (PBPK) model and to identify factors that might cause biodistribution and tumor uptake differences between both peptides. In addition, the effect of tumor burden on peptide biodistribution in gastroenteropancreatic (GEP) neuroendocrine tumor (NET) patients was assessed. METHODS A PBPK model was developed for [68Ga]Ga-(HA-)DOTATATE in GEP-NET patients. Three tumor compartments were added, representing primary tumor, liver metastases and other metastases. Furthermore, reactions describing receptor binding, internalization and recycling, renal clearance and intracellular degradation were added to the model. Scan data from GEP-NET patients were used for evaluation of model predictions. Simulations with increasing tumor volumes were performed to assess the tumor sink effect. RESULTS Data of 39 and 59 patients receiving [68Ga]Ga-DOTATATE and [68Ga]Ga-HA-DOTATATE, respectively, were included. Evaluations showed that the model adequately described image-based patient data and that different receptor affinities caused organ uptake dissimilarities between both peptides. Sensitivity analysis indicated that tumor blood flow and blood volume impacted tumor distribution most. Tumor sink predictions showed a decrease in spleen uptake with increasing tumor volume, which seemed clinically relevant for patients with total tumor volumes higher than ~ 550 mL. CONCLUSION The developed PBPK model adequately predicted tumor and organ uptake for this GEP-NET population. Relevant organ uptake differences between [68Ga]Ga-DOTATATE and [68Ga]Ga-HA-DOTATATE were caused by different affinity profiles, while tumor uptake was mainly affected by tumor blood flow and blood volume. Furthermore, tumor sink predictions showed that for the majority of patients a tumor sink effect is not expected to be clinically relevant.
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Affiliation(s)
- Hinke Siebinga
- grid.430814.a0000 0001 0674 1393Department of Pharmacy and Pharmacology, The Netherlands Cancer Institute, Amsterdam, The Netherlands ,grid.430814.a0000 0001 0674 1393Department of Nuclear Medicine, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Berlinda J. de Wit-van der Veen
- grid.430814.a0000 0001 0674 1393Department of Nuclear Medicine, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Jos H. Beijnen
- grid.430814.a0000 0001 0674 1393Department of Pharmacy and Pharmacology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Thomas P. C. Dorlo
- grid.430814.a0000 0001 0674 1393Department of Pharmacy and Pharmacology, The Netherlands Cancer Institute, Amsterdam, The Netherlands ,grid.8993.b0000 0004 1936 9457Department of Pharmacy, Uppsala University, Uppsala, Sweden
| | - Alwin D. R. Huitema
- grid.430814.a0000 0001 0674 1393Department of Pharmacy and Pharmacology, The Netherlands Cancer Institute, Amsterdam, The Netherlands ,grid.5477.10000000120346234Department of Clinical Pharmacy, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands ,grid.487647.eDepartment of Pharmacology, Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands
| | - Jeroen J. M. A. Hendrikx
- grid.430814.a0000 0001 0674 1393Department of Pharmacy and Pharmacology, The Netherlands Cancer Institute, Amsterdam, The Netherlands ,grid.430814.a0000 0001 0674 1393Department of Nuclear Medicine, The Netherlands Cancer Institute, Amsterdam, The Netherlands
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10
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Müller D, Herrmann H, Schultz MK, Solbach C, Ettrich T, Prasad V. 203 Pb-VMT-α-NET Scintigraphy of a Patient With Neuroendocrine Tumor. Clin Nucl Med 2023; 48:54-55. [PMID: 36257061 PMCID: PMC9762701 DOI: 10.1097/rlu.0000000000004464] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 09/15/2022] [Indexed: 11/26/2022]
Abstract
ABSTRACT In an end-stage midgut neuroendocrine tumor patient with carcinoid heart disease, right ventricular dysfunction, mildly reduced renal function, and refractory to 6 cycles of 177 Lu-HA-DOTATATE therapy, planar, and 22 hours SPECT/CT images were acquired after injection of 224 MBq of 203 Pb-VMT-α-NET to assess the feasibility of performing 212 Pb-VMT-α-NET therapy. A comparison of the 1.5 and 22 hours SPECT/CT images with 68 Ga-HA-DOTATATE PET/CT showed high uptake of 203 Pb-VMT-α-NET in liver metastases matching with the results of the PET/CT investigation.
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Affiliation(s)
- Dirk Müller
- From the Department of Nuclear Medicine, University of Ulm, Ulm, Germany
| | - Hendrik Herrmann
- From the Department of Nuclear Medicine, University of Ulm, Ulm, Germany
| | | | - Christoph Solbach
- From the Department of Nuclear Medicine, University of Ulm, Ulm, Germany
| | - Thomas Ettrich
- Clinic of Internal Medicine, University of Ulm, Ulm, Germany
| | - Vikas Prasad
- From the Department of Nuclear Medicine, University of Ulm, Ulm, Germany
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11
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Evaluation of the Efficacy of a Combined Treatment Using the mTOR-Inhibitor Everolimus and [177Lu]Lu-DOTA-TATE in Nude CD1 Mice with SSTR-Expressing Pancreatic AR42J Xenograft Tumors. Biomedicines 2022; 10:biomedicines10123102. [PMID: 36551858 PMCID: PMC9775670 DOI: 10.3390/biomedicines10123102] [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: 11/13/2022] [Accepted: 11/29/2022] [Indexed: 12/03/2022] Open
Abstract
Therapy options for advanced pancreatic neuroendocrine tumors (pNETs) include the mTOR inhibitor everolimus and peptide receptor radionuclide therapy (PRRT) with [177Lu]Lu-DOTA-TATE, however further optimization in the therapeutic landscape is required as response rates are still low. In this study, we investigated the synergistic and potentially enhanced efficacy of a combined treatment with everolimus and [177Lu]Lu-DOTA-TATE in a mouse model. Baseline [68Ga]Ga-DOTA-TATE PET scans were obtained five days after athymic CD1 mice were inoculated with AR42J tumor cells, before separating the animals into four groups. Group 1 received a placebo, group 2 everolimus, group 3 a placebo and PRRT, and group 4 everolimus and PRRT. The treatment response was monitored by manually measuring the tumor volumes (manual tumor volume, MTV) and conducting sequential [68Ga]Ga-DOTA-TATE PET scans at one, two, and four weeks after treatment induction. The biological tumor volume (BTV) was derived from PET scans using threshold-based volume of interest (VOI) measurements. Tracer uptake was measured semi-quantitatively as a tumor to background ratio (TBR). Mice were euthanized due to excessive tumor growth according to the ethics protocol; blood samples were drawn for the preparation of full blood counts and kidneys were obtained for histological analysis. For the histological assessment, a standardized score (renal damage score, RDS) was used. Full blood counts showed significantly increased numbers of neutrophils and lymphocytes in the groups receiving PRRT. All other parameters did not differ relevantly. In the histological analysis, groups receiving PRRT had a significantly higher RDS, whereas everolimus only tended to cause an increase in the RDS. Mice in groups 1 and 2 had to be euthanized due to excessive tumor growth two weeks after the start of the therapy, whereas follow-up in groups 3 and 4 comprised four weeks. PRRT significantly inhibited tumor growth; the administration of everolimus did not induce an additional effect. A good correlation existed between MTV and BTV. PRRT significantly reduced the TBR. [68Ga]Ga-DOTA-TATE PET is suitable for monitoring tumor growth in the applied model. The high efficacy of [177Lu]Lu-DOTA-TATE is not enhanced by the combination with everolimus.
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12
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Fani M, Mansi R, Nicolas GP, Wild D. Radiolabeled Somatostatin Analogs-A Continuously Evolving Class of Radiopharmaceuticals. Cancers (Basel) 2022; 14:cancers14051172. [PMID: 35267479 PMCID: PMC8909681 DOI: 10.3390/cancers14051172] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 02/21/2022] [Accepted: 02/22/2022] [Indexed: 11/16/2022] Open
Abstract
Somatostatin receptors (SSTs) are recognized as favorable molecular targets in neuroendocrine tumors (NETs) and neuroendocrine neoplasms (NENs), with subtype 2 (SST2) being the predominantly and most frequently expressed. PET/CT imaging with 68Ga-labeled SST agonists, e.g., 68Ga-DOTA-TOC (SomaKit TOC®) or 68Ga-DOTA-TATE (NETSPOT®), plays an important role in staging and restaging these tumors and can identify patients who qualify and would potentially benefit from peptide receptor radionuclide therapy (PRRT) with the therapeutic counterparts 177Lu-DOTA-TOC or 177Lu-DOTA-TATE (Lutathera®). This is an important feature of SST targeting, as it allows a personalized treatment approach (theranostic approach). Today, new developments hold promise for enhancing diagnostic accuracy and therapeutic efficacy. Among them, the use of SST2 antagonists, such as JR11 and LM3, has shown certain advantages in improving image sensitivity and tumor radiation dose, and there is evidence that they may find application in other oncological indications beyond NETs and NENs. In addition, PRRT performed with more cytotoxic α-emitters, such as 225Ac, or β- and Auger electrons, such as 161Tb, presents higher efficacy. It remains to be seen if any of these new developments will overpower the established radiolabeled SST analogs and PRRT with β--emitters.
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Affiliation(s)
- Melpomeni Fani
- Division of Radiopharmaceutical Chemistry, University Hospital Basel, 4031 Basel, Switzerland;
- Correspondence:
| | - Rosalba Mansi
- Division of Radiopharmaceutical Chemistry, University Hospital Basel, 4031 Basel, Switzerland;
| | - Guillaume P. Nicolas
- Division of Nuclear Medicine, University Hospital Basel, 4031 Basel, Switzerland; (G.P.N.); (D.W.)
- ENETS Center of Excellence for Neuroendocrine and Endocrine Tumors, University Hospital Basel, 4031 Basel, Switzerland
| | - Damian Wild
- Division of Nuclear Medicine, University Hospital Basel, 4031 Basel, Switzerland; (G.P.N.); (D.W.)
- ENETS Center of Excellence for Neuroendocrine and Endocrine Tumors, University Hospital Basel, 4031 Basel, Switzerland
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13
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Peptide Receptor Radionuclide Therapy Targeting the Somatostatin Receptor: Basic Principles, Clinical Applications and Optimization Strategies. Cancers (Basel) 2021; 14:cancers14010129. [PMID: 35008293 PMCID: PMC8749814 DOI: 10.3390/cancers14010129] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 12/13/2021] [Accepted: 12/22/2021] [Indexed: 12/12/2022] Open
Abstract
Simple Summary Peptide receptor radionuclide therapy (PRRT) is a systemic treatment consisting of the administration of a tumor-targeting radiopharmaceutical into the circulation of a patient. The radiopharmaceutical will bind to a specific peptide receptor leading to tumor-specific binding and retention. This will subsequently cause lethal DNA damage to the tumor cell. The only target that is currently used in widespread clinical practice is the somatostatin receptor, which is overexpressed on a range of tumor cells, including neuroendocrine tumors and neural-crest derived tumors. Academia played an important role in the development of PRRT, which has led to heterogeneous literature over the last two decades, as no standard radiopharmaceutical or regimen has been available for a long time. This review focuses on the basic principles and clinical applications of PRRT, and discusses several PRRT-optimization strategies. Abstract Peptide receptor radionuclide therapy (PRRT) consists of the administration of a tumor-targeting radiopharmaceutical into the circulation of a patient. The radiopharmaceutical will bind to a specific peptide receptor leading to tumor-specific binding and retention. The only target that is currently used in clinical practice is the somatostatin receptor (SSTR), which is overexpressed on a range of tumor cells, including neuroendocrine tumors and neural-crest derived tumors. Academia played an important role in the development of PRRT, which has led to heterogeneous literature over the last two decades, as no standard radiopharmaceutical or regimen has been available for a long time. This review provides a summary of the treatment efficacy (e.g., response rates and symptom-relief), impact on patient outcome and toxicity profile of PRRT performed with different generations of SSTR-targeting radiopharmaceuticals, including the landmark randomized-controlled trial NETTER-1. In addition, multiple optimization strategies for PRRT are discussed, i.e., the dose–effect concept, dosimetry, combination therapies (i.e., tandem/duo PRRT, chemoPRRT, targeted molecular therapy, somatostatin analogues and radiosensitizers), new radiopharmaceuticals (i.e., SSTR-antagonists, Evans-blue containing vector molecules and alpha-emitters), administration route (intra-arterial versus intravenous) and response prediction via molecular testing or imaging. The evolution and continuous refinement of PRRT resulted in many lessons for the future development of radionuclide therapy aimed at other targets and tumor types.
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14
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Brandt F, Ullrich M, Laube M, Kopka K, Bachmann M, Löser R, Pietzsch J, Pietzsch HJ, van den Hoff J, Wodtke R. "Clickable" Albumin Binders for Modulating the Tumor Uptake of Targeted Radiopharmaceuticals. J Med Chem 2021; 65:710-733. [PMID: 34939412 DOI: 10.1021/acs.jmedchem.1c01791] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The intentional binding of radioligands to albumin gains increasing attention in the context of radiopharmaceutical cancer therapy as it can lead to an enhanced radioactivity uptake into the tumor lesions and, thus, to a potentially improved therapeutic outcome. However, the influence of the radioligand's albumin-binding affinity on the time profile of tumor uptake has been only partly addressed so far. Based on the previously identified Nε-4-(4-iodophenyl)butanoyl-lysine scaffold, we designed "clickable" lysine-derived albumin binders (cLABs) and determined their dissociation constants toward albumin by novel assay methods. Structure-activity relationships were derived, and selected cLABs were applied for the modification of the somatostatin receptor subtype 2 ligand (Tyr3)octreotate. These novel conjugates were radiolabeled with copper-64 and subjected to a detailed in vitro and in vivo radiopharmacological characterization. Overall, the results of this study provide an incentive for further investigations of albumin binders for applications in endoradionuclide therapies.
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Affiliation(s)
- Florian Brandt
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany.,Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, Mommsenstraße 4, 01069 Dresden, Germany
| | - Martin Ullrich
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - Markus Laube
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - Klaus Kopka
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany.,Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, Mommsenstraße 4, 01069 Dresden, Germany
| | - Michael Bachmann
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany.,National Center for Tumor Diseases (NCT) Dresden, University Hospital Carl Gustav Carus, Fetscherstraße 74, 01307 Dresden, Germany
| | - Reik Löser
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany.,Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, Mommsenstraße 4, 01069 Dresden, Germany
| | - Jens Pietzsch
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany.,Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, Mommsenstraße 4, 01069 Dresden, Germany
| | - Hans-Jürgen Pietzsch
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany.,Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, Mommsenstraße 4, 01069 Dresden, Germany
| | - Jörg van den Hoff
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany.,Technische Universität Dresden, Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Fetscherstraße 74, 01307 Dresden, Germany
| | - Robert Wodtke
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany
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15
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Rizzo A, Annunziata S, Salvatori M. Side effects of theragnostic agents currently employed in clinical practice. 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... 2021; 65:315-326. [PMID: 34881848 DOI: 10.23736/s1824-4785.21.03411-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Nuclear medicine plays an increasingly important role in several neoplasms management through a theragnostic approach by which targeted molecular imaging and radiotherapy are obtained with the use of radionuclide pairs with similar characteristics. In some cases, nuclear theragnostic use a pair of agents with identical chemical and biological characteristics while in others are employed theragnostic molecules which are not chemically or biologically identical but show similar biodistribution (so-called "twins in spirit" radiopharmaceuticals). This strategy was developed for the first time over 75 years ago, when iodine-131 was used for diagnostic imaging, confirmation of target expression and radionuclide therapy of thyroid cancer. Other theragnostic approaches were subsequently introduced with significant clinical results and some of them are currently considered standard treatment for different cancers. However, as any other therapy, also nuclear theragnostic treatment carries the potential risk of early deterministic and late stochastic off-target adverse effects, generally minimal and easily managed. This article reviews the reported side effects and risks of the main radiopharmaceuticals used for nuclear theragnostic in oncology for the treatment of thyroid cancer, neuroendocrine neoplasms, adrenergic tumors, metastatic prostate cancer, and liver tumors. Selecting appropriate patients using a multidisciplinary approach, meticulous pretreatment planning and knowledge of methods permit to decrease the incidence of these potential side effects.
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Affiliation(s)
- Alessio Rizzo
- Candiolo Cancer Institute - FPO-IRCCS, Candiolo, Turin, Italy -
| | - Salvatore Annunziata
- Unit of Nuclear Medicine, TracerGLab, Department of Diagnostic Imaging, Oncological Radiotherapy and Hematology, IRCCS A. Gemelli University Polyclinic Foundation, Rome, Italy
| | - Massimo Salvatori
- Institute of Nuclear Medicine, Sacred Heart Catholic University, Rome, Italy
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16
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Siebinga H, de Wit-van der Veen BJ, Beijnen JH, Stokkel MPM, Dorlo TPC, Huitema ADR, Hendrikx JJMA. A physiologically based pharmacokinetic (PBPK) model to describe organ distribution of 68Ga-DOTATATE in patients without neuroendocrine tumors. EJNMMI Res 2021; 11:73. [PMID: 34398356 PMCID: PMC8368277 DOI: 10.1186/s13550-021-00821-7] [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: 07/01/2021] [Accepted: 08/07/2021] [Indexed: 11/10/2022] Open
Abstract
Background Physiologically based pharmacokinetic (PBPK) models combine drug-specific information with prior knowledge on the physiology and biology at the organism level. Whole-body PBPK models contain an explicit representation of the organs and tissue and are a tool to predict pharmacokinetic behavior of drugs. The aim of this study was to develop a PBPK model to describe organ distribution of 68Ga-DOTATATE in a population of patients without detectable neuroendocrine tumors (NETs). Methods Clinical 68Ga-DOTATATE PET/CT data from 41 patients without any detectable somatostatin receptor (SSTR) overexpressing tumors were included. Scans were performed at 45 min (range 30–60 min) after intravenous bolus injection of 68Ga-DOTATATE. Organ (spleen, liver, thyroid) and blood activity levels were derived from PET scans, and corresponding DOTATATE concentrations were calculated. A whole-body PBPK model was developed, including an internalization reaction, receptor recycling, enzymatic reaction for intracellular degradation and renal clearance. SSTR2 expression was added for several organs. Input parameters were fixed or estimated using a built-in Monte Carlo algorithm for parameter identification. Results 68Ga-DOTATATE was administered with a median peptide amount of 12.3 µg (range 8.05–16.9 µg) labeled with 92.7 MBq (range 43.4–129.9 MBq). SSTR2 amounts for spleen, liver and thyroid were estimated at 4.40, 7.80 and 0.0108 nmol, respectively. Variability in observed organ concentrations was best described by variability in SSTR2 expression and differences in administered peptide amounts. Conclusions To conclude, biodistribution of 68Ga-DOTATATE was described with a whole-body PBPK model, where tissue distribution was mainly determined by variability in SSTR2 organ expression and differences in administered peptide amounts.
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Affiliation(s)
- H Siebinga
- Department of Pharmacy and Pharmacology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.,Department of Nuclear Medicine, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - B J de Wit-van der Veen
- Department of Nuclear Medicine, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - J H Beijnen
- Department of Pharmacy and Pharmacology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - M P M Stokkel
- Department of Nuclear Medicine, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - T P C Dorlo
- Department of Pharmacy and Pharmacology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - A D R Huitema
- Department of Pharmacy and Pharmacology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.,Department of Clinical Pharmacy, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands.,Department of Pharmacology, Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands
| | - J J M A Hendrikx
- Department of Pharmacy and Pharmacology, The Netherlands Cancer Institute, Amsterdam, The Netherlands. .,Department of Nuclear Medicine, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
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17
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Naskar N, Lahiri S. Theranostic Terbium Radioisotopes: Challenges in Production for Clinical Application. Front Med (Lausanne) 2021; 8:675014. [PMID: 34136508 PMCID: PMC8200528 DOI: 10.3389/fmed.2021.675014] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 04/06/2021] [Indexed: 12/19/2022] Open
Abstract
Currently, research on terbium has gained a momentum owing to its four short-lived radioisotopes, 149Tb, 152Tb, 155Tb, and 161Tb, all of which can be considered in one or another field of nuclear medicine. The members of this emerging quadruplet family have appealing nuclear characteristics and have the potential to do justice to the proposed theory of theranostics nuclear medicine, which amalgamates therapeutic and diagnostic radioisotopes together. The main challenge for in vivo use of these radioisotopes is to produce them in sufficient quantity. This review discusses that, at present, neither light charged particle nor the heavy ion (HI) activation are suitable for large-scale production of neutron deficient terbium nuclides. Three technological factors like (i) enrichment of stable isotopes to a considerable level, (ii) non-availability of higher energies in commercial cyclotrons, and (iii) non-availability of the isotope separation technique coupled with commercial accelerators limit the large scale production of terbium radionuclides by light charged particle activation. If in future, the technology can overcome these hurdles, then the light charged particle activation of enriched targets would produce a high amount of useful terbium radionuclides. On the other hand, to date, the spallation reaction coupled with an online isotope separator has been found suitable for such a requirement, which has been adopted by the CERN MEDICIS programme. The therapeutic 161Tb radionuclide can be produced in a reactor by neutron bombardment on enriched 160Gd target to produce 161Gd which subsequently decays to 161Tb. The radiochemical separation is mandatory even if the ISOL technique is used to obtain high radioisotopic purity of the desired radioisotope.
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Affiliation(s)
- Nabanita Naskar
- Chemical Sciences Duvision, Saha Institute of Nuclear Physics, Kolkata, India
| | - Susanta Lahiri
- Chemical Sciences Duvision, Saha Institute of Nuclear Physics, Kolkata, India
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18
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Heing‐Becker I, Grötzinger C, Beindorff N, Prasad S, Erdmann S, Exner S, Haag R, Licha K. A Cyanine-Bridged Somatostatin Hybrid Probe for Multimodal SSTR2 Imaging in Vitro and in Vivo: Synthesis and Evaluation. Chembiochem 2021; 22:1307-1315. [PMID: 33238069 PMCID: PMC8048842 DOI: 10.1002/cbic.202000791] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Indexed: 12/20/2022]
Abstract
Multimodal imaging probes have attracted the interest of ongoing research, for example, for the surgical removal of tumors. Modular synthesis approaches allow the construction of hybrid probes consisting of a radiotracer, a fluorophore and a targeting unit. We present the synthesis of a new asymmetric bifunctional cyanine dye that can be used as a structural and functional linker for the construction of such hybrid probes. 68 Ga-DOTATATE, a well-characterized radiopeptide targeting the overexpressed somatostatin receptor subtype 2 (SSTR2) in neuroendocrine tumors, was labeled with our cyanine dye, thus providing additional information along with the data obtained from the radiotracer. We tested the SSTR2-targeting and imaging properties of the resulting probe 68 Ga-DOTA-ICC-TATE in vitro and in a tumor xenograft mouse model. Despite the close proximity between dye and pharmacophore, we observed a high binding affinity towards SSTR2 as well as elevated uptake in SSTR2-overexpressing tumors in the positron emission tomography (PET) scan and histological examination.
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Affiliation(s)
- Isabelle Heing‐Becker
- Institut für Chemie und BiochemieFreie Universität BerlinTakustr. 314195BerlinGermany
| | - Carsten Grötzinger
- Department of Hepatology and GastroenterologyCharité – Universitätsmedizin BerlinAugustenburger Platz 113353BerlinGermany
| | - Nicola Beindorff
- BERIC – Berlin Experimental Radionuclide Imaging CenterCharité – Universitätsmedizin BerlinAugustenburger Platz 113353BerlinGermany
| | - Sonal Prasad
- BERIC – Berlin Experimental Radionuclide Imaging CenterCharité – Universitätsmedizin BerlinAugustenburger Platz 113353BerlinGermany
- Department of Nuclear MedicineCharité – Universitätsmedizin BerlinAugustenburger Platz 113353BerlinGermany
| | - Sarah Erdmann
- Department of Hepatology and GastroenterologyCharité – Universitätsmedizin BerlinAugustenburger Platz 113353BerlinGermany
| | - Samantha Exner
- Department of Hepatology and GastroenterologyCharité – Universitätsmedizin BerlinAugustenburger Platz 113353BerlinGermany
| | - Rainer Haag
- Institut für Chemie und BiochemieFreie Universität BerlinTakustr. 314195BerlinGermany
| | - Kai Licha
- Institut für Chemie und BiochemieFreie Universität BerlinTakustr. 314195BerlinGermany
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Noor A, Van Zuylekom JK, Rudd SE, Roselt PD, Haskali MB, Yan E, Wheatcroft M, Hicks RJ, Cullinane C, Donnelly PS. Imaging Somatostatin Positive Tumors with Tyr 3-Octreotate/Octreotide Conjugated to Desferrioxamine B Squaramide Radiolabeled with either Zirconium-89 or Gallium-68. Bioconjug Chem 2021; 32:1192-1203. [PMID: 33788556 DOI: 10.1021/acs.bioconjchem.1c00109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Radiolabeled derivatives of Tyr3-octreotide and Tyr3-octreotate, synthetic analogues of the peptide hormone somatostatin, can be used for positron emission tomography (PET) imaging of somatostatin receptor expression in neuroendocrine tumors. In this work, a squaramide ester derivative of desferrioxamine B (H3DFOSq) was used attach either Tyr3-octreotide or Tyr3-octreotate to the metal binding ligand to give H3DFOSq-TIDE and H3DFOSq-TATE. These new peptide-H3DFOSq conjugates form stable complexes with either of the positron-emitting radionuclides gallium-68 (t1/2 = 68 min) or zirconium-89 (t1/2 = 3.3 days). The new complexes were evaluated in an AR42J xenograft model that has endogenous expression of SSTR2. All four agents displayed good tumor uptake and produced high-quality PET images. For both radionuclides, the complexes formed with H3DFOSq-TATE performed better, with higher tumor uptake and retention than the complexes formed with H3DFOSq-TIDE. The versatile ligands presented here can be radiolabeled with either gallium-68 or zirconium-89 at room temperature. The long radioactive half-life of zirconium-89 makes distribution of pre-synthesized tracers produced to certified standards feasible and could increase the number of clinical centers that can perform diagnostic PET imaging of neuroendocrine tumors.
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Affiliation(s)
- Asif Noor
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria 3010, Australia
| | | | - Stacey E Rudd
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Peter D Roselt
- Centre for Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne, Victoria 3000, Australia
| | - Mohammad B Haskali
- Centre for Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne, Victoria 3000, Australia
| | - Eddie Yan
- Telix Pharmaceuticals Limited, Suite 401, 55 Flemington Road, North Melbourne, Victoria 3051, Australia
| | - Michael Wheatcroft
- Telix Pharmaceuticals Limited, Suite 401, 55 Flemington Road, North Melbourne, Victoria 3051, Australia
| | - Rodney J Hicks
- Research Division, Peter MacCallum Cancer Centre, Melbourne, Victoria 3000, Australia.,Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Carleen Cullinane
- Research Division, Peter MacCallum Cancer Centre, Melbourne, Victoria 3000, Australia.,Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Paul S Donnelly
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria 3010, Australia
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Synthesis, preclinical evaluation, and a pilot clinical imaging study of [ 18F]AlF-NOTA-JR11 for neuroendocrine neoplasms compared with [ 68Ga]Ga-DOTA-TATE. Eur J Nucl Med Mol Imaging 2021; 48:3129-3140. [PMID: 33630145 DOI: 10.1007/s00259-021-05249-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 02/07/2021] [Indexed: 12/16/2022]
Abstract
PURPOSE A [18F]AlF-labeled somatostatin receptor (SSTR) antagonist was developed for imaging of neuroendocrine neoplasms (NENs), evaluated and compared with [68Ga]Ga-DOTA-TATE. METHOD [18F]AlF-NOTA-JR11 was synthesized manually and qualified with high-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS). The cellular uptake, internalization, and saturation binding were performed with HEK293-SSTR2 cells. Biodistribution and micro-PET imaging were carried out with HEK293-SSTR2 tumor-bearing mice. [18F]AlF-NOTA-JR11 PET/MR imaging and [68Ga]Ga-DOTA-TATE PET/CT were performed with ten patients of NEN at 50~60 min post-injection (p.i.). Normal organ biodistribution and tumor detectability were evaluated. RESULT [18F]AlF-NOTA-JR11(24~36 GBq/μmol) was prepared within 30 min and 51.35 ± 3.30% (n > 10)of radiochemical yield. The radiochemical purity was 98.74 ± 1.24% (n > 10). Two stereoisomers were found and confirmed by LC-MS. The cellular uptake of [18F]AlF-NOTA-JR11 and [68Ga]Ga-DOTA-TATE were 4.50 ± 0.31 and 4.50 ± 0.13 %AD/105 cells at 30 min, and the internalization at 37 °C of [18F]AlF-NOTA-JR11 (5.47 ± 0.32% at 60 min) was significantly lower than [68Ga]Ga-DOTA-TATE (66.89 ± 1.62% at 60 min). The affinity of [18F]AlF-NOTA-JR11 (Kd = 11.59 ± 1.31 nM) was slightly lower than [68Ga]Ga-DOTA-TATE (Kd = 7.36 ± 1.02 nM); [18F]AlF-NOTA-JR11 showed high uptake in tumor (9.02 ± 0.92 %ID/g at 60 min p.i.) which can be blocked by 50 μg of NOTA-JR11 (3.40 ± 1.64 %ID/g at 60 min p.i.); the result was coincident with micro-PET imaging. Imaging study of NEN patients showed that more lesions were found only by [18F]AlF-NOTA-JR11 (n = 67 vs. 1 only by [68Ga]Ga-DOTA-TATE), and the uptakes of [18F]AlF-NOTA-JR11 in majority normal organs were significantly lower than [68Ga]Ga-DOTA-TATE. The target to nontarget of maximum of standard uptake value (SUVmax) of [18F]AlF-NOTA-JR11 in liver lesions were significantly higher than those of [68Ga]Ga-DOTA-TATE. CONCLUSION Qualitied [18F]AlF-NOTA-JR11 is prepared conveniently with reasonable yield, and it can bind SSTR2 specifically with high affinity. Excellent imaging capability of [18F]AlF-NOTA-JR11 for NENs is superior to [68Ga]Ga-DOTA-TATE, especially in digestive system. It has a great potential for imaging of NENs.
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21
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Hall AJ, Haskali MB. Radiolabelled Peptides: Optimal Candidates for Theranostic Application in Oncology. Aust J Chem 2021. [DOI: 10.1071/ch21118] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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22
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Abstract
Over the past decade, theranostic imaging has emerged as a powerful clinical tool in oncology for identifying patients likely to respond to targeted therapies and for monitoring the response of patients to treatment. Herein, we report a theranostic approach to pretargeted radioimmunotherapy (PRIT) based on a pair of radioisotopes of copper: positron-emitting copper-64 (64Cu, t 1/2 = 12.7 h) and beta particle-emitting copper-67 (67Cu, t 1/2 = 61.8 h). This strategy is predicated on the in vivo ligation between a trans-cyclooctene (TCO)-bearing antibody and a tetrazine (Tz)-based radioligand via the rapid and bioorthogonal inverse electron-demand Diels-Alder reaction. Longitudinal therapy studies were conducted in a murine model of human colorectal carcinoma using an immunoconjugate of the huA33 antibody modified with TCO (huA33-TCO) and a 67Cu-labeled Tz radioligand ([67Cu]Cu-MeCOSar-Tz). The injection of huA33-TCO followed 72 h later by the administration of 18.5, 37.0, or 55.5 MBq of [67Cu]Cu-MeCOSar-Tz produced a dose-dependent therapeutic response, with the median survival time increasing from 68 d for the lowest dose to >200 d for the highest. Furthermore, we observed that mice that received the highest dose of [67Cu]Cu-MeCOSar-Tz in a fractionated manner exhibited improved hematological values without sacrificing therapeutic efficacy. Dual radionuclide experiments in which a single administration of huA33-TCO was followed by separate injections of [64Cu]Cu-MeCOSar-Tz and [67Cu]Cu-MeCOSar-Tz revealed that the positron emission tomography images produced by the former accurately predicted the efficacy of the latter. In these experiments, a correlation was observed between the tumoral uptake of [64Cu]Cu-MeCOSar-Tz and the subsequent therapeutic response to [67Cu]Cu-MeCOSar-Tz.
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A new 68Ga-labeled somatostatin analog containing two iodo-amino acids for dual somatostatin receptor subtype 2 and 5 targeting. EJNMMI Res 2020; 10:90. [PMID: 32757150 PMCID: PMC7406630 DOI: 10.1186/s13550-020-00677-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 07/22/2020] [Indexed: 01/02/2023] Open
Abstract
Background Somatostatin receptor (SST) targeting, specifically of the subtype 2 (SST2), with radiolabeled somatostatin analogs, is established for imaging and treatment of neuroendocrine tumors. Owing to the concomitant and heterogeneous expression of several subtypes on the same tumor, analogs targeting more subtypes than SST2 potentially target a broader spectrum of tumors and/or increase the uptake of a given tumor. The analog ST8950 ((4-amino-3-iodo)-d-Phe-c[Cys-(3-iodo)-Tyr-d-Trp-Lys-Val-Cys]-Thr-NH2), bearing 2 iodo-amino acids, exhibits sub-nanomolar affinity to SST2 and SST5. We report herein the development and preclinical evaluation of DOTA-ST8950 labeled with 68Ga, for imaging SST2- and SST5-expressing tumors. Comparative in vitro and in vivo studies were performed with the de-iodinated DOTA-ST8951 ((4-amino)-d-Phe-c[Cys-Tyr-d-Trp-Lys-Val-Cys]-Thr-NH2) and with the reference compounds DOTA-TATE (SST2 selective) and DOTA-NOC (for SST2 and SST5). Results Compared with natGa-DOTA-NOC, natGa-DOTA-ST8950 exhibited higher affinity to SST2 and SST5 (IC50 (95%CI), nM = 0.32 (0.20–0.50) and 1.9 (1.1–3.1) vs 0.70 (0.50-0.96) and 3.4 (1.8-6.2), respectively), while natGa-DOTA-ST8951 lost affinity for both subtypes. natGa-DOTA-ST8950 had the same potency for inducing SST2-mediated cAMP accumulation as natGa-DOTA-TATE and slightly better than natGa-DOTA-NOC (EC50, nM = 0.46 (0.23–0.92) vs 0.47 (0.15–1.5) vs 0.59 (0.18–1.9), respectively). [67Ga]Ga-DOTA-ST8950 had a similar internalization rate as [67Ga]Ga-DOTA-NOC in SST2-expressing cells (12.4 ± 1.6% vs 16.6 ± 2.2%, at 4 h, p = 0.0586). In vivo, [68Ga]Ga-DOTA-ST8950 showed high and specific accumulation in SST2- and SST5-expressing tumors, comparable with [68Ga]Ga-DOTA-NOC (26 ± 8 vs 30 ± 8 %IA/g, p = 0.4630 for SST2 and 15 ± 6 vs 12 ± 5 %IA/g, p = 0.3282, for SST5, 1 h p.i.) and accumulation in the SST-positive tissues, the kidneys and the liver. PET/CT images of [68Ga]Ga-DOTA-ST8950, performed in a dual HEK-SST2 and HEK-SST5 tumor xenografted model, clearly visualized both tumors and illustrated high tumor-to-background contrast. Conclusions [68Ga]Ga-DOTA-ST8950 reveals its potential for PET imaging SST2- and SST5-expressing tumors. It compares favorably with the clinically used [68Ga]Ga-DOTA-NOC in terms of tumor uptake; however, its uptake in the liver remains a challenge for clinical translation. In addition, this study reveals the essential role of the iodo-substitutions in positions 1 and 3 of [68Ga]Ga-DOTA-ST8950 for maintaining affinity to SST2 and SST5, as the de-iodinated [68Ga]Ga-DOTA-ST8951 lost affinity for both receptor subtypes.
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Osl T, Schmidt A, Schwaiger M, Schottelius M, Wester HJ. A new class of PentixaFor- and PentixaTher-based theranostic agents with enhanced CXCR4-targeting efficiency. Am J Cancer Res 2020; 10:8264-8280. [PMID: 32724470 PMCID: PMC7381729 DOI: 10.7150/thno.45537] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 06/05/2020] [Indexed: 02/07/2023] Open
Abstract
Non-invasive PET imaging of CXCR4 expression in cancer and inflammation as well as CXCR4-targeted radioligand therapy (RLT) have recently found their way into clinical research by the development of the theranostic agents [68Ga]PentixaFor (cyclo(D-Tyr1-D-[NMe]Orn2(AMBS-[68Ga]DOTA)-Arg3-Nal4-Gly5) = [68Ga]DOTA-AMBS-CPCR4) and [177Lu/90Y]PentixaTher (cyclo(D-3-iodo-Tyr1-D-[NMe]Orn2(AMBS-[177Lu/90Y]DOTA)-Arg3-Nal4-Gly5) = [177Lu/90Y]DOTA-AMBS-iodoCPCR4). Although convincing clinical results have already been obtained with both agents, this study was designed to further investigate the required structural elements for improved ligand-receptor interaction for both peptide cores (CPCR4 and iodoCPCR4). To this aim, a series of DOTA-conjugated CPCR4- and iodoCPCR4-based ligands with new linker structures, replacing the AMBA-linker in PentixaFor and PentixaTher, were synthesized and evaluated. Methods: The in vitro investigation of the novel compounds alongside with the reference peptides PentixaFor and PentixaTher encompassed the determination of hCXCR4 and mCXCR4 affinity (IC50) of the respective natGa-, natLu-, natY- and natBi-complexes in Jurkat and Eμ-myc 1080 cells using [125I]FC-131 and [125I]CPCR4.3 as radioligands, respectively, as well as the evaluation of the internalization and externalization kinetics of selected 68Ga- and 177Lu-labeled compounds in hCXCR4-transfected Chem-1 cells. Comparative small animal PET imaging studies (1h p.i.) as well as in vivo biodistribution studies (1, 6 and 48h p.i.) were performed in Daudi (human B cell lymphoma) xenograft bearing CB17 SCID mice. Results: Based on the affinity data and cellular uptake studies, [68Ga/177Lu]DOTA-r-a-ABA-CPCR4 and [68Ga/177Lu]DOTA-r-a-ABA-iodoCPCR4 (with r-a-ABA = D-Arg-D-Ala-4-aminobenzoyl-) were selected for further evaluation. Both analogs show app. 10-fold enhanced hCXCR4 affinity compared to the respective references [68Ga]PentixaFor and [177Lu]PentixaTher, four times higher cellular uptake in hCXCR4 expressing cells and improved cellular retention. Unfortunately, the improved in vitro binding and uptake characteristics of [68Ga]DOTA-r-a-ABA-CPCR4 and -iodoCPCR4 could not be recapitulated in initial PET imaging studies; both compounds showed similar uptake in the Daudi xenografts as [68Ga]PentixaFor, alongside with higher background accumulation, especially in the kidneys. However, the subsequent biodistribution studies performed for the corresponding 177Lu-labeled analogs revealed a clear superiority of [177Lu]DOTA-r-a-ABA-CPCR4 and [177Lu]DOTA-r-a-ABA-iodoCPCR4 over [177Lu]PentixaTher with respect to tumor uptake (18.3±3.7 and 17.2±2.0 %iD/g, respectively, at 1h p.i. vs 12.4±3.7%iD/g for [177Lu]PentixaTher) as well as activity retention in tumor up to 48h. Especially for [177Lu]DOTA-r-a-ABA-CPCR4 with its low background accumulation, tumor/organ ratios at 48h were 2- to 4-fold higher than those obtained for [177Lu]PentixaTher (except for kidney). Conclusions: The in-depth evaluation of a series of novel CPCR4- and iodoCPCR4 analogs with modified linker structure has yielded reliable structure-activity relationships. It was generally observed that a) AMBA-by-ABA-substitution leads to enhanced ligand internalization, b) the extension of the ABA-linker by two additional amino acids (DOTA-Xaa2-Xaa1-ABA-) provides sufficient linker length to minimize the interaction of the [M3+]DOTA-chelate with the receptor, and that c) introduction of a cationic side chain (Xaa2) greatly enhances receptor affinity of the constructs, obliterating the necessity for Tyr1-iodination of the pentapeptide core to maintain high receptor affinity (such as in [177Lu]PentixaTher). As a result, [177Lu]DOTA-r-a-ABA-CPCR4 has emerged from this study as a powerful second-generation therapeutic CXCR4 ligand with greatly improved targeting efficiency and tumor retention and will be further evaluated in preclinical and clinical CXCR4-targeted dosimetry and RLT studies.
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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: 74] [Impact Index Per Article: 18.5] [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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Keinänen O, Brennan JM, Membreno R, Fung K, Gangangari K, Dayts EJ, Williams CJ, Zeglis BM. Dual Radionuclide Theranostic Pretargeting. Mol Pharm 2019; 16:4416-4421. [PMID: 31483993 DOI: 10.1021/acs.molpharmaceut.9b00746] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Recent years have played witness to the advent of nuclear theranostics: the synergistic use of "matched pair" radiopharmaceuticals for diagnostic imaging and targeted radiotherapy. In this investigation, we report the extension of this concept to in vivo pretargeting based on the rapid and bioorthogonal inverse electron demand Diels-Alder reaction between tetrazine (Tz) and trans-cyclooctene (TCO). We demonstrate that a single injection of a TCO-modified immunoconjugate can be used as a platform for pretargeted PET imaging and radiotherapy via the sequential administration of a pair of Tz-bearing radioligands labeled with the positron-emitting radiometal copper-64 (t1/2 ≈ 12.7 h) and the beta-emitting radiometal lutetium-177 (t1/2 ≈ 6.7 days). More specifically, a mouse model of human colorectal carcinoma received a dose of the A33 antigen-targeting immunoconjugate huA33-TCO, followed 24 and 48 h later by injections of [64Cu]Cu-SarAr-Tz and [177Lu]Lu-DOTA-PEG7-Tz, respectively. This approach produces high activity concentrations of both radioligands in tumor tissue (16.4 ± 2.7 %ID/g for [64Cu]Cu-SarAr-Tz at 48 h post-injection and 18.1 ± 2.1 %ID/g for [177Lu]Lu-DOTA-PEG7-Tz at 120 h post-injection) as well as promising tumor-to-healthy organ activity concentration ratios. Ultimately, we believe that this work could not only have important implications in nuclear theranostics-most excitingly with isotopologue-based radioligand pairs such as [64Cu]Cu-SarAr-Tz and [67Cu]Cu-SarAr-Tz-but also in the delivery of fractionated doses during pretargeted radioimmunotherapy.
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Affiliation(s)
- Outi Keinänen
- Department of Chemistry , Hunter College, City University of New York , New York , New York 10021 , United States
| | - James M Brennan
- Department of Chemistry , Hunter College, City University of New York , New York , New York 10021 , United States
| | - Rosemery Membreno
- Department of Chemistry , Hunter College, City University of New York , New York , New York 10021 , United States.,Ph.D. Program in Chemistry , The Graduate Center of the City University of New York , New York , New York 10016 , United States
| | - Kimberly Fung
- Department of Chemistry , Hunter College, City University of New York , New York , New York 10021 , United States.,Ph.D. Program in Chemistry , The Graduate Center of the City University of New York , New York , New York 10016 , United States
| | - Kishore Gangangari
- Department of Chemistry , Hunter College, City University of New York , New York , New York 10021 , United States.,Ph.D. Program in Chemistry , The Graduate Center of the City University of New York , New York , New York 10016 , United States
| | - Eric J Dayts
- Department of Chemistry , Hunter College, City University of New York , New York , New York 10021 , United States
| | - Carter J Williams
- Department of Chemistry , Hunter College, City University of New York , New York , New York 10021 , United States
| | - Brian M Zeglis
- Department of Chemistry , Hunter College, City University of New York , New York , New York 10021 , United States.,Ph.D. Program in Chemistry , The Graduate Center of the City University of New York , New York , New York 10016 , United States.,Department of Radiology , Memorial Sloan Kettering Cancer Center , New York , New York 10065 , United States.,Department of Radiology , Weill Cornell Medical College , New York , New York 10065 , United States
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Leisser A, Lukic K, Nejabat M, Wadsak W, Mitterhauser M, Mayerhöfer M, Karnaikas G, Raderer M, Hacker M, Haug A. Sex-differences in [68Ga]Ga-DOTANOC biodistribution. Nucl Med Biol 2019; 76-77:15-20. [DOI: 10.1016/j.nucmedbio.2019.08.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Revised: 08/21/2019] [Accepted: 08/22/2019] [Indexed: 12/22/2022]
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28
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Schottelius M, Ludescher M, Richter F, Kapp TG, Kessler H, Wester HJ. Validation of [ 125I]CPCR4.3 as an investigative tool for the sensitive and specific detection of hCXCR4 and mCXCR4 expression in vitro and in vivo. EJNMMI Res 2019; 9:75. [PMID: 31410585 PMCID: PMC6692420 DOI: 10.1186/s13550-019-0545-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Accepted: 07/24/2019] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND The development and clinical translation of [68Ga] Pentixafor has substantially promoted the relevance of non-invasive PET imaging of CXCR4 expression in a broad spectrum of diseases, including cancer and inflammation. Its pronounced selectivity for the human receptor (hCXCR4), however, precludes the use of [68Ga] Pentixafor for imaging receptor expression and dynamics in CXCR4-related diseases in endogenous mouse models. To overcome this restriction, [125I]CPCR4.3, a structurally related pentapeptide ligand, has been evaluated as a preclinical tool for efficient in vitro and in vivo targeting of hCXCR4 and mCXCR4. RESULTS Compared to the reference [68Ga] Pentixafor, [125I]CPCR4.3 showed 2.4- to 11-fold increased specific binding to human cancer cell lines with different hCXCR4 expression levels (Jurkat, Daudi, HT-29, SH-5YSY, MCF-7, LNCaP) as well as strong and highly specific binding to mCXCR4 expressing cells (mCXCR4-transfected CHO cells, Eμ-myc 1080, 4 T1), which was not detectable for [68Ga]Pentixafor. This is the consequence of the equally high affinity of iodo-CPCR4 to hCXCR4 and mCXCR4 (IC50 = 5.4 ± 1.5 and 4.9 ± 1.7 nM, respectively) as opposed to [natGa] Pentixafor (hCXCR4: 42.4 ± 11.6 nM, mCXCR4: > 1000 nM). Additionally, [125I]CPCR4.3 showed enhanced tracer internalization (factor of 1.5-2 compared to the reference). In vivo biodistribution studies in immunocompetent Black Six and immunocompromised CD-1 nude mice showed predominant hepatobiliary excretion of [125I]CPCR4.3 (logP = 0.51), leading to high activity levels in liver and intestines. However, [125I]CPCR4.3 also showed high and specific accumulation in organs with endogenous mCXCR4 expression (spleen, lung, adrenals), even at low receptor expression levels. CONCLUSIONS Due to its excellent hCXCR4 and mCXCR4 targeting efficiency, both in vitro and in vivo, [125I]CPCR4.3 represents a sensitive and reliable tool for the species-independent quantification of CXCR4 expression. Its suboptimal clearance properties will certainly restrict its use for in vivo imaging applications using 123I (for SPECT) or 124I (for PET), but due to its high and specific accumulation in mCXCR4 expressing tissues, [125I]CPCR4.3 holds promise as a powerful preclinical tool for the investigation and quantification of CXCR4 involvement and kinetics in various murine disease models via, e.g., biodistribution and autoradiography studies.
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Affiliation(s)
- Margret Schottelius
- Chair for Pharmaceutical Radiochemistry, Technische Universität München, Walther-Meissner-Strasse 3, 85748 Garching, Germany
| | - Marina Ludescher
- Chair for Pharmaceutical Radiochemistry, Technische Universität München, Walther-Meissner-Strasse 3, 85748 Garching, Germany
| | - Frauke Richter
- Chair for Pharmaceutical Radiochemistry, Technische Universität München, Walther-Meissner-Strasse 3, 85748 Garching, Germany
| | - Tobias G. Kapp
- Chemistry Department, Institute for Advanced Study, Technische Universität München, Lichtenbergstr. 4, 85747 Garching, Germany
| | - Horst Kessler
- Chemistry Department, Institute for Advanced Study, Technische Universität München, Lichtenbergstr. 4, 85747 Garching, Germany
| | - Hans-Jürgen Wester
- Chair for Pharmaceutical Radiochemistry, Technische Universität München, Walther-Meissner-Strasse 3, 85748 Garching, Germany
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Roxin Á, Zhang C, Huh S, Lepage M, Zhang Z, Lin KS, Bénard F, Perrin DM. A Metal-Free DOTA-Conjugated 18F-Labeled Radiotracer: [18F]DOTA-AMBF3-LLP2A for Imaging VLA-4 Over-Expression in Murine Melanoma with Improved Tumor Uptake and Greatly Enhanced Renal Clearance. Bioconjug Chem 2019; 30:1210-1219. [DOI: 10.1021/acs.bioconjchem.9b00146] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Áron Roxin
- Chemistry Department, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Chengcheng Zhang
- Molecular Oncology, British Columbia Cancer Agency Research Centre, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada
| | - Sungjoon Huh
- Chemistry Department, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Mathieu Lepage
- Chemistry Department, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Zhengxing Zhang
- Molecular Oncology, British Columbia Cancer Agency Research Centre, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada
| | - Kuo-Shyan Lin
- Molecular Oncology, British Columbia Cancer Agency Research Centre, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada
| | - François Bénard
- Molecular Oncology, British Columbia Cancer Agency Research Centre, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada
| | - David M. Perrin
- Chemistry Department, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
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30
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Waldmann CM, Stuparu AD, van Dam RM, Slavik R. The Search for an Alternative to [ 68Ga]Ga-DOTA-TATE in Neuroendocrine Tumor Theranostics: Current State of 18F-labeled Somatostatin Analog Development. Theranostics 2019; 9:1336-1347. [PMID: 30867834 PMCID: PMC6401503 DOI: 10.7150/thno.31806] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 01/14/2019] [Indexed: 02/06/2023] Open
Abstract
The trend to inform personalized molecular radiotherapy with molecular imaging diagnostics, a concept referred to as theranostics, has transformed the field of nuclear medicine in recent years. The development of theranostic pairs comprising somatostatin receptor (SSTR)-targeting nuclear imaging probes and therapeutic agents for the treatment of patients with neuroendocrine tumors (NETs) has been a driving force behind this development. With the Neuroendocrine Tumor Therapy (NETTER-1) phase 3 trial reporting encouraging results in the treatment of well-differentiated, metastatic midgut NETs, peptide radioligand therapy (RLT) with the 177Lu-labeled somatostatin analog (SSA) [177Lu]Lu-DOTA-TATE is now anticipated to become the standard of care. On the diagnostics side, the field is currently dominated by 68Ga-labeled SSAs for the molecular imaging of NETs with positron emission tomography-computed tomography (PET/CT). PET/CT imaging with SSAs such as [68Ga]Ga-DOTA-TATE, [68Ga]Ga-DOTA-TOC, and [68Ga]Ga-DOTA-NOC allows for NET staging with high accuracy and is used to qualify patients for RLT. Driven by the demand for PET/CT imaging of NETs, a commercial kit for the production of [68Ga]Ga-DOTA-TATE (NETSPOT) was approved by the U.S. Food and Drug Administration (FDA). The synthesis of 68Ga-labeled SSAs from a 68Ge/68Ga-generator is straightforward and allows for a decentralized production, but there are economic and logistic difficulties associated with these approaches that warrant the search for a viable, generator-independent alternative. The clinical introduction of an 18F-labeled SSTR-imaging probe can help mitigate the shortcomings of the generator-based synthesis approach, but despite extensive research efforts, none of the proposed 18F-labeled SSAs has been translated past prospective first-in-humans studies so far. Here, we review the current state of probe-development from a translational viewpoint and make a case for a clinically viable, 18F-labeled alternative to the current standard [68Ga]Ga-DOTA-TATE.
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Affiliation(s)
- Christopher M. Waldmann
- Ahmanson Translational Imaging Division, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
- Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Andreea D. Stuparu
- Ahmanson Translational Imaging Division, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
- Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - R. Michael van Dam
- Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
- Crump Institute for Molecular Imaging, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Roger Slavik
- Ahmanson Translational Imaging Division, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
- Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
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31
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Deyev S, Vorobyeva A, Schulga A, Proshkina G, Güler R, Löfblom J, Mitran B, Garousi J, Altai M, Buijs J, Chernov V, Orlova A, Tolmachev V. Comparative Evaluation of Two DARPin Variants: Effect of Affinity, Size, and Label on Tumor Targeting Properties. Mol Pharm 2019; 16:995-1008. [PMID: 30608701 DOI: 10.1021/acs.molpharmaceut.8b00922] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Designed ankyrin repeat proteins (DARPins) are small engineered scaffold proteins that can be selected for binding to desirable molecular targets. High affinity and small size of DARPins render them promising probes for radionuclide molecular imaging. However, detailed knowledge on many factors influencing their imaging properties is still lacking. We have evaluated two human epidermal growth factor 2 (HER2)-specific DARPins with different size and binding properties. DARPins 9_29-H6 and G3-H6 were radiolabeled with iodine-125 and tricarbonyl technetium-99m and evaluated in vitro. A side-by-side comparison of biodistribution and tumor targeting was performed. HER2-specific tumor accumulation of G3-H6 was demonstrated. A combination of smaller size and higher affinity resulted in a higher tumor uptake of G3-H6 in comparison to 9_29-H6. Technetium-99m labeled G3-H6 demonstrated a better biodistribution profile than 9_29-H6, with several-fold lower uptake in liver. Radioiodinated G3-H6 showed the best tumor-to-organ ratios. The combined effect of affinity, molecular weight, scaffold composition, and nonresidualizing properties of iodine label provided radioiodinated G3-H6 with high clinical potential for imaging of HER2.
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Affiliation(s)
- Sergey Deyev
- Molecular Immunology Laboratory , Shemyakin & Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences , Moscow , Russia.,National Research Tomsk Polytechnic University, Tomsk , Russia.,Bio-Nanophotonic Lab., Institute of Engineering Physics for Biomedicine (PhysBio) , National Research Nuclear University "MEPhI" , Moscow , Russia
| | | | - Alexey Schulga
- Molecular Immunology Laboratory , Shemyakin & Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences , Moscow , Russia
| | - Galina Proshkina
- Molecular Immunology Laboratory , Shemyakin & Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences , Moscow , Russia
| | - Rezan Güler
- Department of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology and Health , KTH Royal Institute of Technology , Stockholm , Sweden
| | - John Löfblom
- Department of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology and Health , KTH Royal Institute of Technology , Stockholm , Sweden
| | | | | | | | | | - Vladimir Chernov
- Nuclear Medicine Department, Cancer Research Institute , Tomsk National Research Medical Center Russian Academy of Sciences , Tomsk , Russia
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32
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Günther T, Tulipano G, Dournaud P, Bousquet C, Csaba Z, Kreienkamp HJ, Lupp A, Korbonits M, Castaño JP, Wester HJ, Culler M, Melmed S, Schulz S. International Union of Basic and Clinical Pharmacology. CV. Somatostatin Receptors: Structure, Function, Ligands, and New Nomenclature. Pharmacol Rev 2019; 70:763-835. [PMID: 30232095 PMCID: PMC6148080 DOI: 10.1124/pr.117.015388] [Citation(s) in RCA: 147] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Somatostatin, also known as somatotropin-release inhibitory factor, is a cyclopeptide that exerts potent inhibitory actions on hormone secretion and neuronal excitability. Its physiologic functions are mediated by five G protein-coupled receptors (GPCRs) called somatostatin receptor (SST)1-5. These five receptors share common structural features and signaling mechanisms but differ in their cellular and subcellular localization and mode of regulation. SST2 and SST5 receptors have evolved as primary targets for pharmacological treatment of pituitary adenomas and neuroendocrine tumors. In addition, SST2 is a prototypical GPCR for the development of peptide-based radiopharmaceuticals for diagnostic and therapeutic interventions. This review article summarizes findings published in the last 25 years on the physiology, pharmacology, and clinical applications related to SSTs. We also discuss potential future developments and propose a new nomenclature.
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Affiliation(s)
- Thomas Günther
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Giovanni Tulipano
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Pascal Dournaud
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Corinne Bousquet
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Zsolt Csaba
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Hans-Jürgen Kreienkamp
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Amelie Lupp
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Márta Korbonits
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Justo P Castaño
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Hans-Jürgen Wester
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Michael Culler
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Shlomo Melmed
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Stefan Schulz
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
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Ishizaki A, Mishiro K, Shiba K, Hanaoka H, Kinuya S, Odani A, Ogawa K. Fundamental study of radiogallium-labeled aspartic acid peptides introducing octreotate derivatives. Ann Nucl Med 2019; 33:244-251. [PMID: 30604401 DOI: 10.1007/s12149-018-01326-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 12/20/2018] [Indexed: 01/10/2023]
Abstract
OBJECTIVE Somatostatin receptors are highly expressed in neuroendocrine tumors, and many radiolabeled somatostatin analogs for diagnosis and treatment have been developed. To simultaneously detect not only primary cancer but also bone metastases, this study aimed to develop a positron emission tomography probe using generator-produced nuclide Gallium-68 (T1/2 = 68 min), in which a carrier for primary cancer, a carrier for bone metastases lesions, and a stable gallium complex are introduced into the one molecule. Based on this strategy, the somatostatin receptor-targeted peptide, [Tyr3]-octreotate (TATE), aspartic acid peptide (Dn) with high binding affinity for hydroxyapatite, and Ga-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) as a stable gallium complex were selected. The novel complexes, Ga-DOTA-Dn-TATE (n = 0, 2, 5, 8, or 11), were designed, synthesized, and evaluated. The radiogallium complexes were prepared using the easy-to-handle radioisotope 67Ga due to relatively long half-life. METHODS The radiogallium complex precursor DOTA-Dn-TATE was synthesized by the Fmoc-based solid-phase method and by the air oxidation method to form the disulfide bond. [67Ga]Ga-DOTA-Dn-TATE was synthesized by reacting DOTA-Dn-TATE and 67Ga. Hydroxyapatite binding assays, in vitro cellular uptake experiments in AR42J tumor cells, in biodistribution experiments in AR42J tumor-bearing mice, were performed using [67Ga]Ga-DOTA-Dn-TATE. RESULTS The radiochemical purities of [67Ga]Ga-DOTA-Dn-TATE were > 96.0%. In in vitro and in vivo experiments, [67Ga]Ga-DOTA-D11-TATE had a high affinity for hydroxyapatite and highly accumulated in bone. However, the uptake of [67Ga]Ga-DOTA-D11-TATE into somatostatin receptor-positive AR42J cells was lower than that of [67Ga]Ga-DOTA-TATE, and the accumulation of [67Ga]Ga-DOTA-D11-TATE in tumor was significantly low. CONCLUSION Ga-DOTA-D11-TATE may not be recognized by somatostatin receptor by the introduction of D11, and the charge adjustment may be important for somatostatin receptor-positive cell uptake.
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Affiliation(s)
- Atsushi Ishizaki
- Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Kenji Mishiro
- Institute for Frontier Science Initiative, Kanazawa University, Kakuma-machi, Kanazawa, Japan
| | - Kazuhiro Shiba
- Advanced Science Research Center, Kanazawa University, Kanazawa, Japan
| | - Hirofumi Hanaoka
- Department of Bioimaging Information Analysis, Graduate School of Medicine, Gunma University, Maebashi, Japan
| | - Seigo Kinuya
- Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Akira Odani
- Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Kazuma Ogawa
- Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan. .,Institute for Frontier Science Initiative, Kanazawa University, Kakuma-machi, Kanazawa, Japan.
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Preliminary PET/CT Imaging with Somatostatin Analogs [ 68Ga]DOTAGA-TATE and [ 68Ga]DOTAGA-TOC. Mol Imaging Biol 2018; 19:878-884. [PMID: 28349291 DOI: 10.1007/s11307-017-1072-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
PURPOSE Somatostatin receptor positron emission tomography/X-ray computed tomography (SSTR-PET/CT) is a well-established technique for staging and detection of neuroendocrine tumors (NETs). Ga-68-labeled DOTA-conjugated octreotide analogs are the privileged radiotracers for diagnosis and therapeutic monitoring of NETs. Hence, we were interested in assessing the influence of promising, newer variant DOTAGA on the hydrophilicity, pharmacokinetics, and lesion pick-up of somatostatin analogs. Herein, the potential of ([68Ga]DOTAGA, Tyr3, Thr8) octreotide ([68Ga]DOTAGA-TATE) and ([68Ga]DOTAGA, Tyr3) octreotide ([68Ga]DOTAGA-TOC) as NET imaging agents has been investigated. PROCEDURES Amenability of [68Ga]DOTAGA-(TATE/TOC) to kit-type formulation has been demonstrated. Biodistribution studies were carried out in normal rats at 1 h post-injection (p.i.). [68Ga]DOTAGA-(TATE/TOC) PET/CT scans were carried out in patients (70-170 MBq, 1 h p.i.) with histologically confirmed well-differentiated NETs. RESULTS [68Ga]DOTAGA-TATE exhibited hydrophilicity similar to [68Ga]DOTA-TATE (log P = -3.51 vs -3.69) whereas [68Ga]DOTAGA-TOC was more hydrophilic than [68Ga]DOTA-TOC (log P = -3.27 vs -2.93). [68Ga]DOTAGA-TATE and [68Ga]DOTA-TATE showed almost identical blood and kidney uptake in normal rats whereas significantly fast clearance (p < 0.05) of [68Ga]DOTAGA-TATE was observed from other non-specific organs (liver, lungs, spleen, intestine). [68Ga]DOTAGA-TOC also demonstrated rapid clearance from blood and kidneys (p < 0.05) in comparison to [68Ga]DOTA-TOC. The metastatic lesions in NET patients were well identified by [68Ga]DOTAGA-TATE and [68Ga]DOTAGA-TOC. CONCLUSION The phenomenal analogy was observed between [68Ga]DOTAGA-TATE and [68Ga]DOTA-TATE as well as between [68Ga]DOTAGA-TOC and [68Ga]DOTA-TOC in biodistribution studies in rats. The good lesion detection ability of the two radiotracers indicates their potential as NET imaging radiotracers.
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Ballinger JR. Theranostic radiopharmaceuticals: established agents in current use. Br J Radiol 2018; 91:20170969. [PMID: 29474096 DOI: 10.1259/bjr.20170969] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Although use of the term "theranostic" is relatively recent, the concept goes back to the earliest days of nuclear medicine, with the use of radioiodine for diagnosis and therapy of benign and malignant thyroid disease being arguably the most successful molecular radiotherapy in history. A diagnostic scan with 123I-, 124I-, or a low activity of 131I-iodide is followed by therapy with high activity 131I-iodide. Similarly, adrenergic tumours such as phaeochromocytoma and neuroblastoma can be imaged with 123I-metaiodobenzylguanidine and treated with 131I-metaiodobenzylguanidine. Bone scintigraphy can be used to select patients with painful bone metastases from prostate cancer who may benefit from treatment with beta- or alpha-particle emitting bone seeking agents, the most recent and successful of which is 223Ra radium chloride. Anti-CD20 monoclonal antibodies can be used to image and treat non-Hodgkins lymphoma, though this has not been as commercially successful as initially predicted. More recently established theranostics include somatostatin receptor targeting peptides for diagnosis and treatment of neuroendocrine tumours with agents such as 68Ga-DOTATATE and 177Lu-DOTATATE, respectively. Finally, agents which target prostate-specific membrane antigen are becoming increasingly widely available, despite the current lack of a commercial product. With the recent licensing of the somatostatin peptides and the rapid adoption of 68Ga- and 177Lu-labelled prostate-specific membrane antigen targeting agents, we have built upon the experience of radioiodine and are already seeing a great expansion in the availability of widely accepted theranostic radiopharmaceuticals.
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Affiliation(s)
- James R Ballinger
- 1 Department of Imaging Chemistry and Biology, School of Biomedical Engineering and Imaging Sciences, King's College London , London , UK
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Fani M, Nicolas GP, Wild D. Somatostatin Receptor Antagonists for Imaging and Therapy. J Nucl Med 2017; 58:61S-66S. [PMID: 28864614 DOI: 10.2967/jnumed.116.186783] [Citation(s) in RCA: 160] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 04/26/2017] [Indexed: 02/07/2023] Open
Abstract
Somatostatin receptor (sstr) scintigraphy for imaging and sstr analogs for treatment have been used for more than 20 y. An important improvement in recent years was the introduction of peptide receptor radionuclide therapy with radiolabeled sstr agonists, such as [90Y-DOTA0,Tyr3]octreotide or [177Lu-DOTA0,Tyr3]octreotide (90Y- or 177Lu-DOTATOC, respectively) and [177Lu-DOTA0,Tyr3]octreotate (177Lu-DOTATATE). PET/CT with 68Ga-labeled sstr agonists, such as 68Ga-DOTATOC, 68Ga-DOTATATE, and [68Ga-DOTA,1-Nal3]octreotide (68Ga-DOTANOC), plays an important role in staging and restaging neuroendocrine tumors. Most importantly, sstr scintigraphy and sstr PET/CT can distinguish patients who will qualify for and benefit from peptide receptor radionuclide therapy. This characteristic of sstr targeting is important because it allows a personalized treatment approach (theranostic approach). Until recently, it was thought that internalization of the radiolabeled agonist was mandatory for sstr-mediated imaging and therapy. It was Ginj et al. who proposed in 2006 the paradigm shift that radiolabeled sstr antagonists may perform better than agonists despite the lack of internalization. Despite the rather limited number of head-to-head comparisons of sstr antagonists and agonists, the superiority of sstr antagonists was demonstrated in several cases. From a small library of sstr antagonists, the analog JR11 (Cpa-c[d-Cys-Aph(Hor)-d-Aph(Cbm)-Lys-Thr-Cys]-d-Tyr-NH2), an antagonist with selectivity for sstr subtype 2, showed the best overall characteristics for sstr subtype 2 targeting and was therefore selected for clinical translation. JR11 is under clinical development as a PET imaging agent when labeled with 68Ga (68Ga-NODAGA-JR11 or 68Ga-OPS202) and as a therapeutic agent when labeled with 177Lu (177Lu-DOTA-JR11 or 177Lu-OPS201). In this article, we discuss the development and current status of radiolabeled sstr antagonists. Evidence based on preclinical work, on quantitative in vivo autoradiography of human tumor slices, and on human data now supports a shift to sstr antagonists.
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Affiliation(s)
- Melpomeni Fani
- Division of Nuclear Medicine, University Hospital Basel, Basel, Switzerland.,Division of Radiopharmaceutical Chemistry, University Hospital Basel, Basel, Switzerland; and
| | - Guillaume P Nicolas
- Division of Nuclear Medicine, University Hospital Basel, Basel, Switzerland.,Center for Neuroendocrine and Endocrine Tumors, University Hospital Basel, Basel, Switzerland
| | - Damian Wild
- Division of Nuclear Medicine, University Hospital Basel, Basel, Switzerland .,Center for Neuroendocrine and Endocrine Tumors, University Hospital Basel, Basel, Switzerland
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Jackson IM, Scott PJ, Thompson S. Clinical Applications of Radiolabeled Peptides for PET. Semin Nucl Med 2017; 47:493-523. [DOI: 10.1053/j.semnuclmed.2017.05.007] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Brogsitter C, Hartmann H, Wunderlich G, Schottelius M, Wester HJ, Kotzerke J. Twins in spirit part IV - [ 177Lu] high affinity DOTATATE. A promising new tracer for peptide receptor radiotherapy? Nuklearmedizin 2017; 56:1-8. [PMID: 28138688 DOI: 10.3413/nukmed-0860-16-11] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Accepted: 01/26/2017] [Indexed: 01/10/2023]
Abstract
AIM Besides the use of somatostatin analogues, small molecules like sunitinib and everolimus as well as conventional chemotherapy, peptide receptor radiotherapy (PRRT) using radiolabelled somatostatin analogues has gained an important role in the treatment of inoperable, metastasized neuroendocrine tumours (NET). There are various radiotracers in use. Based on our experience with the PET tracer [68Ga]DOTA-3-iodo-Tyr3-octreotate ([68Ga]HA-DOTATATE), a DOTATATE derivative with an increased binding affinity to hsst5, the current retrospective analysis is exploring the therapeutic potential of [177Lu]HA-DOTATATE. METHODS Eighteen patients with metastatic NET (G1/G2) were treated using [177Lu]DOTATATE and/or [177Lu]HA-DOTATATE, and dosimetric results of both tracers were compared. RESULTS Using [177Lu]HA-DOTATATE, a mean tumour dose of 5.34 Gy/GBq (median 2.53 Gy/GBq; range 0.89-33.3 Gy/GBq) was achieved, while [177Lu]DOTATATE delivered a tumour dose of 5.53 Gy/GBq (median 2.70 Gy/GBq; range 0.44-15.3 Gy/GBq). Organ doses for [177Lu]HA-DOTATATE vs. [177Lu]DOTATATE were as follows: kidney 2.31 ± 0.85 vs. 2.03 ± 0.96 Gy/GBq, liver 1.06 ± 0.79 vs. 1.67 ± 1.73 Gy/GBq, spleen 3.89 ± 4.04 vs. 4.50 ± 3.69 Gy/GBq and whole body 0.16 ± 0.10 Gy/GBq vs. 0.15 ± 0.08 Gy/GBq. Tumour-to-kidney dose ratio was slightly higher for [177Lu]DOTATATE (2.4 ± 5.6) compared to [177Lu]HA-DOTATATE (1.5 ± 3.6). CONCLUSION Both tracers showed marked inter-patient variation in their dosimetry, and no significant differences in dosimetry of [177Lu]HA-DOTATATE and [177Lu]DOTATATE were observed when taking all patients into account. Thus, [177Lu]HA-DOTATATE appears viable for PRRT, although it was marginally inferior regarding kidney dose and tumour-to-kidney dose ratio compared to the established [177Lu]DOTATATE.
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Affiliation(s)
- Claudia Brogsitter
- Claudia Brogsitter, Fetscherstr. 74, 01307 Dresden, Germany, Tel. +49-351-458 4160, Fax. +49-351-458 5347, E-Mail:
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Garousi J, Honarvar H, Andersson KG, Mitran B, Orlova A, Buijs J, Löfblom J, Frejd FY, Tolmachev V. Comparative Evaluation of Affibody Molecules for Radionuclide Imaging of in Vivo Expression of Carbonic Anhydrase IX. Mol Pharm 2016; 13:3676-3687. [PMID: 27529191 DOI: 10.1021/acs.molpharmaceut.6b00502] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Overexpression of the enzyme carbonic anhydrase IX (CAIX) is documented for chronically hypoxic malignant tumors as well as for normoxic renal cell carcinoma. Radionuclide molecular imaging of CAIX would be useful for detection of hypoxic areas in malignant tumors, for patients' stratification for CAIX-targeted therapies, and for discrimination of primary malignant and benign renal tumors. Earlier, we have reported feasibility of in vivo radionuclide based imaging of CAIX expressing tumors using Affibody molecules, small affinity proteins based on a nonimmunoglobulin scaffold. In this study, we compared imaging properties of several anti-CAIX Affibody molecules having identical scaffold parts and competing for the same epitope on CAIX, but having different binding paratopes. Four variants were labeled using residualizing 99mTc and nonresidualizing 125I labels. All radiolabeled variants demonstrated high-affinity detection of CAIX-expressing cell line SK-RC-52 in vitro and specific accumulation in SK-RC-52 xenografts in vivo. 125I-labeled conjugates demonstrated much lower radioactivity uptake in kidneys but higher radioactivity concentration in blood compared with 99mTc-labeled counterparts. Although all variants cleared rapidly from blood and nonspecific compartments, there was noticeable difference in their biodistribution. The best variant for imaging of expression of CAIX in disseminated cancer was 99mTc-(HE)3-ZCAIX:2 providing tumor uptake of 16.3 ± 0.9% ID/g and tumor-to-blood ratio of 44 ± 7 at 4 h after injection. For primary renal cell carcinoma, the most promising imaging candidate was 125I-ZCAIX:4 providing tumor-kidney ratio of 2.1 ± 0.5. In conclusion, several clones of scaffold proteins should be evaluated to select the best variant for development of an imaging probe with optimal sensitivity for the intended application.
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Affiliation(s)
- Javad Garousi
- Department of Immunology, Genetics and Pathology, Uppsala University , SE-75285 Uppsala, Sweden
| | - Hadis Honarvar
- Department of Immunology, Genetics and Pathology, Uppsala University , SE-75285 Uppsala, Sweden
| | - Ken G Andersson
- Division of Protein Technology, School of Biotechnology, KTH-Royal Institute of Technology , SE-106 91 Stockholm, Sweden
| | - Bogdan Mitran
- Division of Molecular Imaging, Department of Medicinal Chemistry, Uppsala University , SE-751 83 Uppsala, Sweden
| | - Anna Orlova
- Division of Molecular Imaging, Department of Medicinal Chemistry, Uppsala University , SE-751 83 Uppsala, Sweden
| | - Jos Buijs
- Department of Immunology, Genetics and Pathology, Uppsala University , SE-75285 Uppsala, Sweden.,Ridgeview Instruments AB , SE-74020 Vänge, Sweden
| | - John Löfblom
- Division of Protein Technology, School of Biotechnology, KTH-Royal Institute of Technology , SE-106 91 Stockholm, Sweden
| | - Fredrik Y Frejd
- Department of Immunology, Genetics and Pathology, Uppsala University , SE-75285 Uppsala, Sweden.,Affibody AB , SE-171 63 Stockholm, Sweden
| | - Vladimir Tolmachev
- Department of Immunology, Genetics and Pathology, Uppsala University , SE-75285 Uppsala, Sweden
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Charron CL, Farnsworth AL, Roselt PD, Hicks RJ, Hutton CA. Recent developments in radiolabelled peptides for PET imaging of cancer. Tetrahedron Lett 2016. [DOI: 10.1016/j.tetlet.2016.07.083] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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Ullrich M, Bergmann R, Peitzsch M, Zenker EF, Cartellieri M, Bachmann M, Ehrhart-Bornstein M, Block NL, Schally AV, Eisenhofer G, Bornstein SR, Pietzsch J, Ziegler CG. Multimodal Somatostatin Receptor Theranostics Using [(64)Cu]Cu-/[(177)Lu]Lu-DOTA-(Tyr(3))octreotate and AN-238 in a Mouse Pheochromocytoma Model. Theranostics 2016; 6:650-65. [PMID: 27022413 PMCID: PMC4805660 DOI: 10.7150/thno.14479] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 02/10/2016] [Indexed: 12/17/2022] Open
Abstract
Pheochromocytomas and extra-adrenal paragangliomas (PHEO/PGLs) are rare catecholamine-producing chromaffin cell tumors. For metastatic disease, no effective therapy is available. Overexpression of somatostatin type 2 receptors (SSTR2) in PHEO/PGLs promotes interest in applying therapies using somatostatin analogs linked to radionuclides and/or cytotoxic compounds, such as [177Lu]Lu-DOTA-(Tyr3)octreotate (DOTATATE) and AN-238. Systematic evaluation of such therapies for the treatment of PHEO/PGLs requires sophisticated animal models. In this study, the mouse pheochromocytoma (MPC)-mCherry allograft model showed high tumor densities of murine SSTR2 (mSSTR2) and high tumor uptake of [64Cu]Cu-DOTATATE. Using tumor sections, we assessed mSSTR2-specific binding of DOTATATE, AN-238, and somatostatin-14. Therapeutic studies showed substantial reduction of tumor growth and tumor-related renal monoamine excretion in tumor-bearing mice after treatment with [177Lu]Lu-DOTATATE compared to AN-238 and doxorubicin. Analyses did not show agonist-dependent receptor downregulation after single mSSTR2-targeting therapies. This study demonstrates that the MPC-mCherry model is a uniquely powerful tool for the preclinical evaluation of SSTR2-targeting theranostic applications in vivo. Our findings highlight the therapeutic potential of somatostatin analogs, especially of [177Lu]Lu-DOTATATE, for the treatment of metastatic PHEO/PGLs. Repeated treatment cycles, fractionated combinations of SSTR2-targeting radionuclide and cytotoxic therapies, and other adjuvant compounds addressing additional mechanisms may further enhance therapeutic outcome.
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Ma MT, Cullinane C, Waldeck K, Roselt P, Hicks RJ, Blower PJ. Rapid kit-based (68)Ga-labelling and PET imaging with THP-Tyr(3)-octreotate: a preliminary comparison with DOTA-Tyr(3)-octreotate. EJNMMI Res 2015; 5:52. [PMID: 26452495 PMCID: PMC4600075 DOI: 10.1186/s13550-015-0131-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 09/30/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Ge/(68)Ga generators provide an inexpensive source of a PET isotope to hospitals without cyclotron facilities. The development of new (68)Ga-based molecular imaging agents and subsequent clinical translation would be greatly facilitated by simplification of radiochemical syntheses. We report the properties of a tris(hydroxypyridinone) conjugate of the SSTR2-targeted peptide, Tyr(3)-octreotate (TATE), and compare the (68)Ga-labelling and biodistribution of [(68)Ga(THP-TATE)] with the clinical radiopharmaceutical [(68)Ga(DOTATATE)]. METHODS A tris(hydroxypyridinone) with a pendant isothiocyanate group was conjugated to the primary amine terminus of H2N-PEG2-Lys(iv-Dde)(5)-TATE, and the resulting conjugate was deprotected to provide THP-TATE. THP-TATE was radiolabelled with (68)Ga(3+) from a (68)Ge/(68)Ga generator. In vitro uptake was assessed in SSTR2-positive 427-7 cells and SSTR2-negative 427 (parental) cells. Biodistribution of [(68)Ga(THP-TATE)] was compared with that of [(68)Ga(DOTATATE)] in Balb/c nude mice bearing SSTR2-positive AR42J tumours. PET scans were obtained 1 h post-injection, after which animals were euthanised and tissues/organs harvested and counted. RESULTS [(68)Ga(THP-TATE)] was radiolabelled and formulated rapidly in <2 min, in ≥95 % radiochemical yield at pH 5-6.5 and specific activities of 60-80 MBq nmol(-1) at ambient temperature. [(68)Ga(THP-TATE)] was rapidly internalised into SSTR2-positive cells, but not SSTR2-negative cells, and receptor binding and internalisation were specific. Animals administered [(68)Ga(THP-TATE)] demonstrated comparable SSTR2-positive tumour activity (11.5 ± 0.6 %ID g(-1)) compared to animals administered [(68)Ga(DOTATATE)] (14.4 ± 0.8 %ID g(-1)). Co-administration of unconjugated Tyr(3)-octreotate effectively blocked tumour accumulation of [(68)Ga(THP-TATE)] (2.7 ± 0.6 %ID g(-1)). Blood clearance of [(68)Ga(THP-TATE)] was rapid and excretion was predominantly renal, although compared to [(68)Ga(DOTATATE)], [(68)Ga(THP-TATE)] exhibited comparatively longer kidney retention. CONCLUSIONS Radiochemical synthesis of [(68)Ga(THP-TATE)] is significantly faster, proceeds under milder conditions, and requires less manipulation than that of [(68)Ga(DOTATATE)]. A (68)Ga-labelled tris(hydroxypyridinone) conjugate of Tyr(3)-octreotate demonstrates specificity and targeting affinity for SSTR2 receptors, with comparable in vivo targeting affinity to the clinical PET tracer, [(68)Ga(DOTATATE)]. Thus, peptide conjugates based on tris(hydroxypyridinones) are conducive to translation to kit-based preparation of PET tracers, enabling the expansion and adoption of (68)Ga PET in hospitals and imaging centres without the need for costly automated synthesis modules.
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Affiliation(s)
- Michelle T Ma
- Division of Imaging Sciences and Biomedical Engineering, King's College London, 4th Floor Lambeth Wing, St Thomas' Hospital, London, SE1 7EH, UK.
| | - Carleen Cullinane
- Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, Victoria, Australia
| | - Kelly Waldeck
- Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
| | - Peter Roselt
- Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
| | - Rodney J Hicks
- Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, Victoria, Australia
| | - Philip J Blower
- Division of Imaging Sciences and Biomedical Engineering, King's College London, 4th Floor Lambeth Wing, St Thomas' Hospital, London, SE1 7EH, UK
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Sahlmann CO, Meller B, Bouter C, Ritter CO, Ströbel P, Lotz J, Trojan L, Meller J, Hijazi S. Biphasic ⁶⁸Ga-PSMA-HBED-CC-PET/CT in patients with recurrent and high-risk prostate carcinoma. Eur J Nucl Med Mol Imaging 2015; 43:898-905. [PMID: 26563122 DOI: 10.1007/s00259-015-3251-y] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 10/30/2015] [Indexed: 12/26/2022]
Abstract
PURPOSE Binding of (68)Ga-PSMA-HBED-CC ((68)Ga-PSMA) at prostate cancer (PC) cells increases over time. A biphasic protocol may help separating benign from tumor lesions. The aim of this study was the retrospective evaluation of a diagnostic incremental value of a dual-time point (biphasic) (68)Ga-PSMA-PET/CT in patients with prostate cancer. METHODS Retrospective analysis of 35 consecutive patients (49-78 years, median 71) with newly diagnosed PC (12/35) or recurrence of PC (23/35). PET/CT (Gemini TF16, Philips) was acquired 1 h and 3 h p. i. of 140-392 MBq (300 MBq median) (68)Ga-PSMA, followed by a diagnostic contrast CT. PET findings were correlated with histology or unequivocal CT findings. Semiquantitative PET data (SUVmax, SUV mean) were acquired and target-to-background-ratios (T/B-ratio) were calculated for benign and malign lesions for both time points. Size of lymph nodes (LN) on diagnostic CT was recorded. Statistical analysis was performed for assessment of significant changes of semiquantitative PET-parameters over time and for correlation of size and uptake of lymph nodes. RESULTS One hundred and four lesions were evaluated. Sixty lesions were referenced by histology or unequivocal CT findings, including eight (13.3 %) histopathologically benign lymph nodes, 12 (20 %) histopathologically lymph node metastases, 12 (20 %) primary tumors, three (5 %) local recurrences, and 25 (41.7 %) bone metastases. Forty-four lesions were axillary LN with normal CT-appearance. Benign lesions had significantly lower SUVmax and T/B-ratios compared with malignant findings. Malign lesions showed a significant increase of both parameters over time compared to benign findings. There was no correlation between LN size and SUVmax. The sensitivity, specificity, the positive predictive value and negative predictive value of PET/CT regarding pelvic LN was 94 %, 99 %, 89 %, and 99.5 %, respectively. CONCLUSIONS In contrast to benign tissues, the uptake of proven tumor lesions increases on (68)Ga-PSMA-PET/CT over time. A biphasic PET-study may lead to a better detection of tumor lesions in unequivocal findings.
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Affiliation(s)
- Carsten-Oliver Sahlmann
- Department of Nuclear Medicine, University Medical Center Goettingen, Robert-Koch-Str. 40, D-37075, Goettingen, Germany.
| | - Birgit Meller
- Department of Nuclear Medicine, University Medical Center Goettingen, Robert-Koch-Str. 40, D-37075, Goettingen, Germany
| | - Caroline Bouter
- Department of Nuclear Medicine, University Medical Center Goettingen, Robert-Koch-Str. 40, D-37075, Goettingen, Germany
| | - Christian Oliver Ritter
- Department of Diagnostic and Interventional Radiology, University Medical Center Goettingen, Goettingen, Germany
| | - Philipp Ströbel
- Department of Pathology, University Medical Center Goettingen, Goettingen, Germany
| | - Joachim Lotz
- Department of Diagnostic and Interventional Radiology, University Medical Center Goettingen, Goettingen, Germany
| | - Lutz Trojan
- Department of Urology, University Medical Center Goettingen, Goettingen, Germany
| | - Johannes Meller
- Department of Nuclear Medicine, University Medical Center Goettingen, Robert-Koch-Str. 40, D-37075, Goettingen, Germany
| | - Sameh Hijazi
- Department of Urology, University Medical Center Goettingen, Goettingen, Germany
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