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Helal CJ, Arnold EP, Boyden TL, Chang C, Chappie TA, Fennell KF, Forman MD, Hajos M, Harms JF, Hoffman WE, Humphrey JM, Kang Z, Kleiman RJ, Kormos BL, Lee CW, Lu J, Maklad N, McDowell L, Mente S, O’Connor RE, Pandit J, Piotrowski M, Schmidt AW, Schmidt CJ, Ueno H, Verhoest PR, Yang EX. Application of Structure-Based Design and Parallel Chemistry to Identify a Potent, Selective, and Brain Penetrant Phosphodiesterase 2A Inhibitor. J Med Chem 2017; 60:5673-5698. [DOI: 10.1021/acs.jmedchem.7b00397] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Christopher J. Helal
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Eric P. Arnold
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Tracey L. Boyden
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Cheng Chang
- Pfizer Worldwide Research and Development, 610 Main Street, Cambridge, Massachusetts 02139, United States
| | - Thomas A. Chappie
- Pfizer Worldwide Research and Development, 610 Main Street, Cambridge, Massachusetts 02139, United States
| | - Kimberly F. Fennell
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Michael D. Forman
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Mihaly Hajos
- Pfizer Worldwide Research and Development, 610 Main Street, Cambridge, Massachusetts 02139, United States
| | - John F. Harms
- Pfizer Worldwide Research and Development, 610 Main Street, Cambridge, Massachusetts 02139, United States
| | - William E. Hoffman
- Pfizer Worldwide Research and Development, 610 Main Street, Cambridge, Massachusetts 02139, United States
| | - John M. Humphrey
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Zhijun Kang
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Robin J. Kleiman
- Pfizer Worldwide Research and Development, 610 Main Street, Cambridge, Massachusetts 02139, United States
| | - Bethany L. Kormos
- Pfizer Worldwide Research and Development, 610 Main Street, Cambridge, Massachusetts 02139, United States
| | - Che-Wah Lee
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Jiemin Lu
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Noha Maklad
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Laura McDowell
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Scot Mente
- Pfizer Worldwide Research and Development, 610 Main Street, Cambridge, Massachusetts 02139, United States
| | - Rebecca E. O’Connor
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Jayvardhan Pandit
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Mary Piotrowski
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Anne W. Schmidt
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Christopher J. Schmidt
- Pfizer Worldwide Research and Development, 610 Main Street, Cambridge, Massachusetts 02139, United States
| | - Hirokazu Ueno
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Patrick R. Verhoest
- Pfizer Worldwide Research and Development, 610 Main Street, Cambridge, Massachusetts 02139, United States
| | - Edward X. Yang
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
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Abstract
In the current issue of ACS Chemical Neuroscience, Kim et al. report on the early characterization of 4-(3-[18F] fluorophenethoxy)pyrimidine (18F-FPP) as a new positron emission tomography radiotracer for imaging brain 5-HT2C receptors ( Kim, J., et al. ( 2017 ) A potential PET radiotracer for the 5-HT2c receptor: Synthesis and in vivo evaluation of 4-(3-[18F]Fluorophenethoxy)pyrimidine. ACS Chem. Neurosci. , DOI 10.1021/acschemneuro.6b00445 ). At the present time, the tracer properties of 18F-FPP have only been reported in rats. If 18F-FPP is indeed shown to be suitable as a 5-HT2C receptor PET tracer in humans, it will very likely have an important impact both in the development of any new chemical entities (NCEs) targeted to 5-HT2C receptors, as well as a tool to advance understanding of 5-HT2C receptor function both in normal and abnormal brain states.
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Affiliation(s)
- Guy A. Higgins
- InterVivo Solutions Inc., 120 Carlton Street, Toronto, ON M5A
4K2, Canada
- Department of Pharmacology & Toxicology, University of Toronto, 1 King’s College Circle, Toronto, ON M5S 1A8, Canada
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104
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Approaches for the discovery of novel positron emission tomography radiotracers for brain imaging. Clin Transl Imaging 2017. [DOI: 10.1007/s40336-017-0221-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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105
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Target Engagement Measures in Preclinical Drug Discovery: Theory, Methods, and Case Studies. TRANSLATING MOLECULES INTO MEDICINES 2017. [DOI: 10.1007/978-3-319-50042-3_3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Abstract
The discovery and development of central nervous system (CNS) drugs is an extremely challenging process requiring large resources, timelines, and associated costs. The high risk of failure leads to high levels of risk. Over the past couple of decades PET imaging has become a central component of the CNS drug-development process, enabling decision-making in phase I studies, where early discharge of risk provides increased confidence to progress a candidate to more costly later phase testing at the right dose level or alternatively to kill a compound through failure to meet key criteria. The so called "3 pillars" of drug survival, namely; tissue exposure, target engagement, and pharmacologic activity, are particularly well suited for evaluation by PET imaging. This review introduces the process of CNS drug development before considering how PET imaging of the "3 pillars" has advanced to provide valuable tools for decision-making on the critical path of CNS drug development. Finally, we review the advances in PET science of biomarker development and analysis that enable sophisticated drug-development studies in man.
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Affiliation(s)
- Roger N Gunn
- Imanova Ltd, London, United Kingdom; Division of Brain Sciences, Imperial College London, London, United Kingdom; Department of Engineering Science, Institute of Biomedical Engineering, University of Oxford, Oxford, United Kingdom.
| | - Eugenii A Rabiner
- Imanova Ltd, London, United Kingdom; Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King's College London, London, United Kingdom
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107
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Zhang L, Villalobos A. Strategies to facilitate the discovery of novel CNS PET ligands. EJNMMI Radiopharm Chem 2016; 1:13. [PMID: 29564389 PMCID: PMC5843814 DOI: 10.1186/s41181-016-0016-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 08/17/2016] [Indexed: 01/08/2023] Open
Abstract
Positron Emission Tomography (PET), as a non-invasive translatable imaging technology, can be incorporated into various stages of the CNS drug discovery process to provide valuable information for key preclinical and clinical decision-making. Novel CNS PET ligand discovery efforts in the industry setting, however, are facing unique challenges associated with lead design and prioritization, and budget constraints. In this review, three strategies aiming toward improving the central nervous system (CNS) PET ligand discovery process are described: first, early determination of receptor density (Bmax) and bio-distribution to inform PET viability and resource allocation; second, rational design and design prioritization guided by CNS PET design parameters; finally, a cost-effective in vivo specific binding assessment using a liquid chromatography-mass spectrometry (LC-MS/MS) “cold tracer” method. Implementation of these strategies allowed a more focused and rational CNS PET ligand discovery effort to identify high quality PET ligands for neuroimaging.
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Affiliation(s)
- Lei Zhang
- Neuroscience and Pain Medicinal Chemistry, Pfizer Worldwide Research and Development, 610 Main Street, Cambridge, MA 02139 USA
| | - Anabella Villalobos
- Neuroscience and Pain Medicinal Chemistry, Pfizer Worldwide Research and Development, 610 Main Street, Cambridge, MA 02139 USA
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108
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Smith DL, Davoren JE, Edgerton JR, Lazzaro JT, Lee CW, Neal S, Zhang L, Grimwood S. Characterization of a Novel M1 Muscarinic Acetylcholine Receptor Positive Allosteric Modulator Radioligand, [3H]PT-1284. Mol Pharmacol 2016; 90:177-87. [DOI: 10.1124/mol.116.104737] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 06/30/2016] [Indexed: 12/18/2022] Open
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109
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Trabanco AA, Buijnsters P, Rombouts FJR. Towards selective phosphodiesterase 2A (PDE2A) inhibitors: a patent review (2010 - present). Expert Opin Ther Pat 2016; 26:933-46. [PMID: 27321640 DOI: 10.1080/13543776.2016.1203902] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
INTRODUCTION The cyclic nucleotides cAMP and cGMP are ubiquitous intracellular second messengers regulating a large variety of biological processes. The intracellular concentration of these biologically relevant molecules is modulated by the activity of phosphodiesterases (PDEs), a class of enzymes that is grouped in 11 families. The expression of PDEs is tissue- and cell-specific allowing spatiotemporal integration of multiple signaling cascades. PDE2A is a dual substrate enzyme and is expressed in both the periphery and in the central nervous system, however its expression is highest in the brain, where it is mainly localized in the cortex, hippocampus, and striatum. This suggests that this enzyme may regulate intraneuronal cGMP and cAMP levels in brain areas involved in emotion, perception, concentration, learning and memory. AREAS COVERED This review covers the patent applications published between January 2010 and February 2016 on phosphodiesterase 2A inhibitors. EXPERT OPINION Recent publications in the literature and in filed patent applications demonstrate the interest of pharmaceutical companies for PDE2A. This has increased the insights of its possible therapeutic role but the few clinical trials were terminated. Based on the ongoing interest in the field it is likely that new clinical trials can be expected and will unravel the therapeutic potential of PDE2A inhibition.
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Affiliation(s)
- Andrés A Trabanco
- a A Division of Janssen-Cilag S.A., Neuroscience Medicinal Chemistry Department , Janssen Research and Development , Toledo , Spain
| | - Peter Buijnsters
- b A Division of Janssen Pharmaceutica N.V., Neuroscience Medicinal Chemistry Department , Janssen Research and Development , Beerse , Belgium
| | - Frederik J R Rombouts
- b A Division of Janssen Pharmaceutica N.V., Neuroscience Medicinal Chemistry Department , Janssen Research and Development , Beerse , Belgium
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Wang L, Mori W, Cheng R, Yui J, Hatori A, Ma L, Zhang Y, Rotstein BH, Fujinaga M, Shimoda Y, Yamasaki T, Xie L, Nagai Y, Minamimoto T, Higuchi M, Vasdev N, Zhang MR, Liang SH. Synthesis and Preclinical Evaluation of Sulfonamido-based [(11)C-Carbonyl]-Carbamates and Ureas for Imaging Monoacylglycerol Lipase. Am J Cancer Res 2016; 6:1145-59. [PMID: 27279908 PMCID: PMC4893642 DOI: 10.7150/thno.15257] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 03/18/2016] [Indexed: 12/22/2022] Open
Abstract
Monoacylglycerol lipase (MAGL) is a 33 kDa member of the serine hydrolase superfamily that preferentially degrades 2-arachidonoylglycerol (2-AG) to arachidonic acid in the endocannabinoid system. Inhibition of MAGL is not only of interest for probing the cannabinoid pathway but also as a therapeutic and diagnostic target for neuroinflammation. Limited attempts have been made to image MAGL in vivo and a suitable PET ligand for this target has yet to be identified and is urgently sought to guide small molecule drug development in this pathway. Herein we synthesized and evaluated the physiochemical properties of an array of eleven sulfonamido-based carbamates and ureas with a series of terminal aryl moieties, linkers and leaving groups. The most potent compounds were a novel MAGL inhibitor, N-((1-(1H-1,2,4-triazole-1-carbonyl)piperidin-4-yl) methyl)-4-chlorobenzenesulfonamide (TZPU; IC50 = 35.9 nM), and the known inhibitor 1,1,1,3,3,3-hexafluoropropan-2-yl 4-(((4-chlorophenyl)sulfonamido) methyl)piperidine-1-carboxylate (SAR127303; IC50 = 39.3 nM), which were also shown to be selective for MAGL over fatty acid amide hydrolase (FAAH), and cannabinoid receptors (CB1 & CB2). Both of these compounds were radiolabeled with carbon-11 via [11C]COCl2, followed by comprehensive ex vivo biodistribution and in vivo PET imaging studies in normal rats to determine their brain permeability, specificity, clearance and metabolism. Whereas TZPU did not show adequate specificity to warrant further evaluation, [11C]SAR127303 was advanced for preliminary PET neuroimaging studies in nonhuman primate. The tracer showed good brain permeability (ca. 1 SUV) and heterogeneous regional brain distribution which is consistent with the distribution of MAGL.
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111
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Auberson YP, Briard E, Sykes D, Reilly J, Healy M. Ligand Specific Efficiency (LSE) Index for PET Tracer Optimization. ChemMedChem 2016; 11:1415-27. [DOI: 10.1002/cmdc.201600112] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 04/13/2016] [Indexed: 11/08/2022]
Affiliation(s)
- Yves P. Auberson
- Novartis Institutes for BioMedical Research; Klybeckstrasse 141 4057 Basel Switzerland
| | - Emmanuelle Briard
- Novartis Institutes for BioMedical Research; Klybeckstrasse 141 4057 Basel Switzerland
| | - David Sykes
- University of Nottingham; Cell Signalling Department; Nottingham NG7 2RD UK
| | - John Reilly
- Novartis Institutes for BioMedical Research; 250 Massachusetts Avenue Cambridge MA 02139 USA
| | - Mark Healy
- Novartis Institutes for BioMedical Research; 250 Massachusetts Avenue Cambridge MA 02139 USA
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112
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Novel Radioligands for Cyclic Nucleotide Phosphodiesterase Imaging with Positron Emission Tomography: An Update on Developments Since 2012. Molecules 2016; 21:molecules21050650. [PMID: 27213312 PMCID: PMC6273803 DOI: 10.3390/molecules21050650] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Revised: 05/09/2016] [Accepted: 05/10/2016] [Indexed: 12/19/2022] Open
Abstract
Cyclic nucleotide phosphodiesterases (PDEs) are a class of intracellular enzymes that inactivate the secondary messenger molecules, cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP). Thus, PDEs regulate the signaling cascades mediated by these cyclic nucleotides and affect fundamental intracellular processes. Pharmacological inhibition of PDE activity is a promising strategy for treatment of several diseases. However, the role of the different PDEs in related pathologies is not completely clarified yet. PDE-specific radioligands enable non-invasive visualization and quantification of these enzymes by positron emission tomography (PET) in vivo and provide an important translational tool for elucidation of the relationship between altered expression of PDEs and pathophysiological effects as well as (pre-)clinical evaluation of novel PDE inhibitors developed as therapeutics. Herein we present an overview of novel PDE radioligands for PET published since 2012.
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113
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Chen L, Nabulsi N, Naganawa M, Zasadny K, Skaddan MB, Zhang L, Najafzadeh S, Lin SF, Helal CJ, Boyden TL, Chang C, Ropchan J, Carson RE, Villalobos A, Huang Y. Preclinical Evaluation of 18F-PF-05270430, a Novel PET Radioligand for the Phosphodiesterase 2A Enzyme. J Nucl Med 2016; 57:1448-53. [PMID: 27199356 DOI: 10.2967/jnumed.115.171454] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 04/14/2016] [Indexed: 12/13/2022] Open
Abstract
UNLABELLED The enzyme phosphodiesterase 2A (PF-05270430) is a potential target for development of novel therapeutic agents for the treatment of cognitive impairments. The goal of the present study was to evaluate the PDE2A ligand (18)F-PF-05270430, 4-(3-fluoroazetidin-1-yl)-7-methyl-5-(1-methyl-5-(4-(trifluoromethyl)phenyl)-1H-pyrazol-4-yl)imidazo[1,5-f][1,2,4]triazine, in nonhuman primates. METHODS (18)F-PF-05270430 was radiolabeled by 2 methods via nucleophilic substitution of its tosylate precursor. Tissue metabolite analysis in rodents and PET imaging in nonhuman primates under baseline and blocking conditions were performed to determine the pharmacokinetic and binding characteristics of the new radioligand. Various kinetic modeling approaches were assessed to select the optimal method for analysis of imaging data. RESULTS (18)F-PF-05270430 was synthesized in greater than 98% radiochemical purity and high specific activity. In the nonhuman primate brain, uptake of (18)F-PF-05270430 was fast, with peak concentration (SUVs of 1.5-1.8 in rhesus monkeys) achieved within 7 min after injection. The rank order of uptake was striatum > neocortical regions > cerebellum. Regional time-activity curves were well fitted by the 2-tissue-compartment model and the multilinear analysis-1 (MA1) method to arrive at reliable estimates of regional distribution volume (VT) and binding potential (BPND) with 120 min of scan data. Regional VT values (MA1) ranged from 1.28 mL/cm(3) in the cerebellum to 3.71 mL/cm(3) in the putamen, with a BPND of 0.25 in the temporal cortex and 1.92 in the putamen. Regional BPND values estimated by the simplified reference tissue model (SRTM) were similar to those from MA1. Test-retest variability in high-binding regions (striatum) was 4% ± 6% for MA1 VT, 13% ± 6% for MA1 BPND, and 13% ± 7% SRTM BPND, respectively. Pretreatment of animals with the PDE2A inhibitor PF-05180999 resulted in a dose-dependent reduction of (18)F-PF-05270430 specific binding, with a half maximal effective concentration of 69.4 ng/mL in plasma PF-05180999 concentration. CONCLUSION (18)F-PF-05270430 displayed fast and reversible kinetics in nonhuman primates, as well as specific binding blockable by a PDE2A inhibitor. This is the first PET tracer with desirable imaging properties and demonstrated ability to image and quantify PDE2A in vivo.
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Affiliation(s)
- Laigao Chen
- Pfizer Worldwide Research and Development, Groton, Connecticut; and
| | - Nabeel Nabulsi
- PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, Connecticut
| | - Mika Naganawa
- PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, Connecticut
| | - Kenneth Zasadny
- Pfizer Worldwide Research and Development, Groton, Connecticut; and
| | - Marc B Skaddan
- Pfizer Worldwide Research and Development, Groton, Connecticut; and
| | - Lei Zhang
- Pfizer Worldwide Research and Development, Groton, Connecticut; and
| | - Soheila Najafzadeh
- PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, Connecticut
| | - Shu-Fei Lin
- PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, Connecticut
| | | | - Tracey L Boyden
- Pfizer Worldwide Research and Development, Groton, Connecticut; and
| | - Cheng Chang
- Pfizer Worldwide Research and Development, Groton, Connecticut; and
| | - Jim Ropchan
- PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, Connecticut
| | - Richard E Carson
- PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, Connecticut
| | | | - Yiyun Huang
- PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, Connecticut
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114
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Naganawa M, Waterhouse RN, Nabulsi N, Lin SF, Labaree D, Ropchan J, Tarabar S, DeMartinis N, Ogden A, Banerjee A, Huang Y, Carson RE. First-in-Human Assessment of the Novel PDE2A PET Radiotracer 18F-PF-05270430. J Nucl Med 2016; 57:1388-95. [PMID: 27103022 DOI: 10.2967/jnumed.115.166850] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 03/14/2016] [Indexed: 01/18/2023] Open
Abstract
UNLABELLED This was a first-in-human study of the novel phosphodiesterase-2A (PDE2A) PET ligand (18)F-PF-05270430. The primary goals were to determine the appropriate tracer kinetic model to quantify brain uptake and to examine the within-subject test-retest variability. METHODS In advance of human studies, radiation dosimetry was determined in nonhuman primates. Six healthy male subjects participated in a test-retest protocol with dynamic scans and metabolite-corrected input functions. Nine brain regions of interest were studied, including the striatum, white matter, neocortical regions, and cerebellum. Multiple modeling methods were applied to calculate volume of distribution (VT) and binding potentials relative to the nondisplaceable tracer in tissue (BPND), concentration of tracer in plasma (BPP), and free tracer in tissue (BPF). The cerebellum was selected as a reference region to calculate binding potentials. RESULTS The dosimetry study provided an effective dose of less than 0.30 mSv/MBq, with the gallbladder as the critical organ; the human target dose was 185 MBq. There were no adverse events or clinically detectable pharmacologic effects reported. Tracer uptake was highest in the striatum, followed by neocortical regions and white matter, and lowest in the cerebellum. Regional time-activity curves were well fit by multilinear analysis-1, and a 70-min scan duration was sufficient to quantify VT and the binding potentials. BPND, with mean values ranging from 0.3 to 0.8, showed the best intrasubject and intersubject variability and reliability. Test-retest variability in the whole brain (excluding the cerebellum) of VT, BPND, and BPP were 8%, 16%, and 17%, respectively. CONCLUSION (18)F-PF-05270430 shows promise as a PDE2A PET ligand, albeit with low binding potential values.
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Affiliation(s)
- Mika Naganawa
- Department of Radiology and Biomedical Imaging, PET Center, Yale School of Medicine, New Haven, Connecticut; and
| | | | - Nabeel Nabulsi
- Department of Radiology and Biomedical Imaging, PET Center, Yale School of Medicine, New Haven, Connecticut; and
| | - Shu-Fei Lin
- Department of Radiology and Biomedical Imaging, PET Center, Yale School of Medicine, New Haven, Connecticut; and
| | - David Labaree
- Department of Radiology and Biomedical Imaging, PET Center, Yale School of Medicine, New Haven, Connecticut; and
| | - Jim Ropchan
- Department of Radiology and Biomedical Imaging, PET Center, Yale School of Medicine, New Haven, Connecticut; and
| | - Sanela Tarabar
- Pfizer Worldwide Research and Development, Cambridge, Massachusetts
| | | | - Adam Ogden
- Pfizer Worldwide Research and Development, Cambridge, Massachusetts
| | | | - Yiyun Huang
- Department of Radiology and Biomedical Imaging, PET Center, Yale School of Medicine, New Haven, Connecticut; and
| | - Richard E Carson
- Department of Radiology and Biomedical Imaging, PET Center, Yale School of Medicine, New Haven, Connecticut; and
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115
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Cummins DJ, Bell MA. Integrating Everything: The Molecule Selection Toolkit, a System for Compound Prioritization in Drug Discovery. J Med Chem 2016; 59:6999-7010. [DOI: 10.1021/acs.jmedchem.5b01338] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- David J. Cummins
- Eli Lilly and Company, 893 South
Delaware Street, Indianapolis, Indiana 46285, United States
| | - Michael A. Bell
- Eli Lilly and Company, 893 South
Delaware Street, Indianapolis, Indiana 46285, United States
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116
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Pike VW. Considerations in the Development of Reversibly Binding PET Radioligands for Brain Imaging. Curr Med Chem 2016; 23:1818-69. [PMID: 27087244 PMCID: PMC5579844 DOI: 10.2174/0929867323666160418114826] [Citation(s) in RCA: 130] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 04/04/2016] [Accepted: 04/15/2016] [Indexed: 12/17/2022]
Abstract
The development of reversibly binding radioligands for imaging brain proteins in vivo, such as enzymes, neurotransmitter transporters, receptors and ion channels, with positron emission tomography (PET) is keenly sought for biomedical studies of neuropsychiatric disorders and for drug discovery and development, but is recognized as being highly challenging at the medicinal chemistry level. This article aims to compile and discuss the main considerations to be taken into account by chemists embarking on programs of radioligand development for PET imaging of brain protein targets.
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Affiliation(s)
- Victor W Pike
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Rm. B3C346A, 10 Center Drive, Bethesda, MD 20892, USA.
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117
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Recent Advances in the Development and Application of Radiolabeled Kinase Inhibitors for PET Imaging. Molecules 2015; 20:22000-27. [PMID: 26690113 PMCID: PMC6332294 DOI: 10.3390/molecules201219816] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 11/18/2015] [Accepted: 12/01/2015] [Indexed: 12/20/2022] Open
Abstract
Over the last 20 years, intensive investigation and multiple clinical successes targeting protein kinases, mostly for cancer treatment, have identified small molecule kinase inhibitors as a prominent therapeutic class. In the course of those investigations, radiolabeled kinase inhibitors for positron emission tomography (PET) imaging have been synthesized and evaluated as diagnostic imaging probes for cancer characterization. Given that inhibitor coverage of the kinome is continuously expanding, in vivo PET imaging will likely find increasing applications for therapy monitoring and receptor density studies both in- and outside of oncological conditions. Early investigated radiolabeled inhibitors, which are mostly based on clinically approved tyrosine kinase inhibitor (TKI) isotopologues, have now entered clinical trials. Novel radioligands for cancer and PET neuroimaging originating from novel but relevant target kinases are currently being explored in preclinical studies. This article reviews the literature involving radiotracer design, radiochemistry approaches, biological tracer evaluation and nuclear imaging results of radiolabeled kinase inhibitors for PET reported between 2010 and mid-2015. Aspects regarding the usefulness of pursuing selective vs. promiscuous inhibitor scaffolds and the inherent challenges associated with intracellular enzyme imaging will be discussed.
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118
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Oi N, Tokunaga M, Suzuki M, Nagai Y, Nakatani Y, Yamamoto N, Maeda J, Minamimoto T, Zhang MR, Suhara T, Higuchi M. Development of Novel PET Probes for Central 2-Amino-3-(3-hydroxy-5-methyl-4-isoxazolyl)propionic Acid Receptors. J Med Chem 2015; 58:8444-62. [DOI: 10.1021/acs.jmedchem.5b00712] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Norihito Oi
- Tsukuba
Research Laboratories, Eisai Co., Ltd., 5-1-3 Tokodai, Tsukuba, Ibaraki 300-2635, Japan
- Molecular
Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, Chiba 263-8555, Japan
| | - Masaki Tokunaga
- Molecular
Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, Chiba 263-8555, Japan
| | - Michiyuki Suzuki
- Tsukuba
Research Laboratories, Eisai Co., Ltd., 5-1-3 Tokodai, Tsukuba, Ibaraki 300-2635, Japan
- Molecular
Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, Chiba 263-8555, Japan
| | - Yuji Nagai
- Molecular
Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, Chiba 263-8555, Japan
| | - Yosuke Nakatani
- Tsukuba
Research Laboratories, Eisai Co., Ltd., 5-1-3 Tokodai, Tsukuba, Ibaraki 300-2635, Japan
- Molecular
Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, Chiba 263-8555, Japan
| | - Noboru Yamamoto
- Tsukuba
Research Laboratories, Eisai Co., Ltd., 5-1-3 Tokodai, Tsukuba, Ibaraki 300-2635, Japan
| | - Jun Maeda
- Molecular
Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, Chiba 263-8555, Japan
| | - Takafumi Minamimoto
- Molecular
Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, Chiba 263-8555, Japan
| | - Ming-Rong Zhang
- Molecular
Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, Chiba 263-8555, Japan
| | - Tetsuya Suhara
- Molecular
Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, Chiba 263-8555, Japan
| | - Makoto Higuchi
- Molecular
Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, Chiba 263-8555, Japan
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Bocan TM, Panchal RG, Bavari S. Applications of in vivo imaging in the evaluation of the pathophysiology of viral and bacterial infections and in development of countermeasures to BSL3/4 pathogens. Mol Imaging Biol 2015; 17:4-17. [PMID: 25008802 PMCID: PMC4544652 DOI: 10.1007/s11307-014-0759-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
While preclinical and clinical imaging have been applied to drug discovery/development and characterization of disease pathology, few examples exist where imaging has been used to evaluate infectious agents or countermeasures to biosafety level (BSL)3/4 threat agents. Viruses engineered with reporter constructs, i.e., enzymes and receptors, which are amenable to detection by positron emission tomography (PET), single photon emission tomography (SPECT), or magnetic resonance imaging (MRI) have been used to evaluate the biodistribution of viruses containing specific therapeutic or gene transfer payloads. Bioluminescence and nuclear approaches involving engineered reporters, direct labeling of bacteria with radiotracers, or tracking bacteria through their constitutively expressed thymidine kinase have been utilized to characterize viral and bacterial pathogens post-infection. Most PET, SPECT, CT, or MRI approaches have focused on evaluating host responses to the pathogens such as inflammation, brain neurochemistry, and structural changes and on assessing the biodistribution of radiolabeled drugs. Imaging has the potential when applied preclinically to the development of countermeasures against BSL3/4 threat agents to address the following: (1) presence, biodistribution, and time course of infection in the presence or absence of drug; (2) binding of the therapeutic to the target; and (3) expression of a pharmacologic effect either related to drug mechanism, efficacy, or safety. Preclinical imaging could potentially provide real-time dynamic tools to characterize the pathogen and animal model and for developing countermeasures under the U.S. FDA Animal Rule provision with high confidence of success and clinical benefit.
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Affiliation(s)
- Thomas M Bocan
- Molecular and Translational Sciences, US Army Medical Research Institute of Infectious Diseases (USAMRIID), 1425 Porter Street, Ft. Detrick, MD, 21702, USA,
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120
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Zhang Z, Kil KE, Poutiainen P, Choi JK, Kang HJ, Huang XP, Roth BL, Brownell AL. Re-exploring the N-phenylpicolinamide derivatives to develop mGlu4 ligands with improved affinity and in vitro microsomal stability. Bioorg Med Chem Lett 2015; 25:3956-60. [PMID: 26231155 DOI: 10.1016/j.bmcl.2015.07.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 07/10/2015] [Accepted: 07/13/2015] [Indexed: 10/23/2022]
Abstract
In recent years, mGlu4 has received great attention and research effort because of the potential benefits of mGlu4 activation in treating numerous brain disorders, such as Parkinson's disease (PD). Many positive allosteric modulators of mGlu4 have been developed. To better understand the role of mGlu4 in healthy and disease conditions, we are interested in developing an mGlu4 selective radioligand for in vivo studies. Thus, we had synthesized and studied [(11)C]2 as a PET tracer for mGlu4, which demonstrated some promising features as a PET radioligand as well as the limitation need to be improved. In order to develop an mGlu4 ligand with enhanced affinity and improved metabolic stability, we have modified, synthesized and evaluated a series of new N-phenylpicolinamide derivatives. The SAR study has discovered a number of compounds with low nM affinity to mGlu4. The dideuteriumfluoromethoxy modified compound 24 is identified as a very promising mGlu4 ligand, which has demonstrated enhanced affinity, improved in vitro microsomal stability, good selectivity and good permeability.
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Affiliation(s)
- Zhaoda Zhang
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, 149, 13th Street, Suite 2301, Charlestown, MA 02129, United States
| | - Kun-Eek Kil
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, 149, 13th Street, Suite 2301, Charlestown, MA 02129, United States
| | - Pekka Poutiainen
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, 149, 13th Street, Suite 2301, Charlestown, MA 02129, United States
| | - Ji-Kyung Choi
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, 149, 13th Street, Suite 2301, Charlestown, MA 02129, United States
| | - Hye-Jin Kang
- Department of Pharmacology, University of North Carolina Chapel Hill School of Medicine, Chapel Hill, NC 27514, United States
| | - Xi-Ping Huang
- Department of Pharmacology, University of North Carolina Chapel Hill School of Medicine, Chapel Hill, NC 27514, United States
| | - Bryan L Roth
- Department of Pharmacology, University of North Carolina Chapel Hill School of Medicine, Chapel Hill, NC 27514, United States
| | - Anna-Liisa Brownell
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, 149, 13th Street, Suite 2301, Charlestown, MA 02129, United States.
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121
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Schröder S, Wenzel B, Deuther-Conrad W, Teodoro R, Egerland U, Kranz M, Scheunemann M, Höfgen N, Steinbach J, Brust P. Synthesis, 18F-Radiolabelling and Biological Characterization of Novel Fluoroalkylated Triazine Derivatives for in Vivo Imaging of Phosphodiesterase 2A in Brain via Positron Emission Tomography. Molecules 2015; 20:9591-615. [PMID: 26016549 PMCID: PMC6272448 DOI: 10.3390/molecules20069591] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Revised: 05/04/2015] [Accepted: 05/18/2015] [Indexed: 12/31/2022] Open
Abstract
Phosphodiesterase 2A (PDE2A) is highly and specifically expressed in particular brain regions that are affected by neurological disorders and in certain tumors. Development of a specific PDE2A radioligand would enable molecular imaging of the PDE2A protein via positron emission tomography (PET). Herein we report on the syntheses of three novel fluoroalkylated triazine derivatives (TA2–4) and on the evaluation of their effect on the enzymatic activity of human PDE2A. The most potent PDE2A inhibitors were 18F-radiolabelled ([18F]TA3 and [18F]TA4) and investigated regarding their potential as PET radioligands for imaging of PDE2A in mouse brain. In vitro autoradiography on rat brain displayed region-specific distribution of [18F]TA3 and [18F]TA4, which is consistent with the expression pattern of PDE2A protein. Metabolism studies of both [18F]TA3 and [18F]TA4 in mice showed a significant accumulation of two major radiometabolites of each radioligand in brain as investigated by micellar radio-chromatography. Small-animal PET/MR studies in mice using [18F]TA3 revealed a constantly increasing uptake of activity in the non-target region cerebellum, which may be caused by the accumulation of brain penetrating radiometabolites. Hence, [18F]TA3 and [18F]TA4 are exclusively suitable for in vitro investigation of PDE2A. Nevertheless, further structural modification of these promising radioligands might result in metabolically stable derivatives.
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Affiliation(s)
- Susann Schröder
- Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Permoserstraße 15, Leipzig 04318, Germany.
| | - Barbara Wenzel
- Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Permoserstraße 15, Leipzig 04318, Germany.
| | - Winnie Deuther-Conrad
- Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Permoserstraße 15, Leipzig 04318, Germany.
| | - Rodrigo Teodoro
- Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Permoserstraße 15, Leipzig 04318, Germany.
| | - Ute Egerland
- BioCrea GmbH, Meissner Str. 191, Radebeul 01445, Germany.
| | - Mathias Kranz
- Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Permoserstraße 15, Leipzig 04318, Germany.
| | - Matthias Scheunemann
- Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Permoserstraße 15, Leipzig 04318, Germany.
| | - Norbert Höfgen
- BioCrea GmbH, Meissner Str. 191, Radebeul 01445, Germany.
| | - Jörg Steinbach
- Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Permoserstraße 15, Leipzig 04318, Germany.
| | - Peter Brust
- Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Permoserstraße 15, Leipzig 04318, Germany.
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122
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Herth MM, Knudsen GM. Current radiosynthesis strategies for 5-HT2Areceptor PET tracers. J Labelled Comp Radiopharm 2015; 58:265-73. [DOI: 10.1002/jlcr.3288] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Revised: 03/10/2015] [Accepted: 03/16/2015] [Indexed: 11/12/2022]
Affiliation(s)
- Matthias M. Herth
- Center for Integrated Molecular Brain Imaging; Rigshospitalet and University of Copenhagen; Blegdamsvej 9 Copenhagen DK-2100 Denmark
- Department of Drug Design and Pharmacology; University of Copenhagen; Jagtvej 160 Copenhagen DK-2100 Denmark
| | - Gitte M. Knudsen
- Center for Integrated Molecular Brain Imaging; Rigshospitalet and University of Copenhagen; Blegdamsvej 9 Copenhagen DK-2100 Denmark
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123
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Labeling and preliminary in vivo evaluation of the 5-HT7 receptor selective agonist [11C]E-55888. Bioorg Med Chem Lett 2015; 25:1901-4. [DOI: 10.1016/j.bmcl.2015.03.039] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Revised: 03/12/2015] [Accepted: 03/16/2015] [Indexed: 01/08/2023]
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124
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Durham TB, Blanco MJ. Target Engagement in Lead Generation. Bioorg Med Chem Lett 2015; 25:998-1008. [DOI: 10.1016/j.bmcl.2014.12.076] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Revised: 12/15/2014] [Accepted: 12/23/2014] [Indexed: 12/15/2022]
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125
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Ariza M, Kolb HC, Moechars D, Rombouts F, Andrés JI. Tau Positron Emission Tomography (PET) Imaging: Past, Present, and Future. J Med Chem 2015; 58:4365-82. [DOI: 10.1021/jm5017544] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Manuela Ariza
- Neuroscience Medicinal Chemistry, Janssen Research and Development, a Division of Janssen Pharmaceutica NV, Turnhoutseweg 30, B-2340 Beerse, Belgium
| | - Hartmuth C. Kolb
- Neuroscience Biomarkers, Janssen Research and Development, 3210 Merryfield Row, San Diego, California 92121, United States
| | - Dieder Moechars
- Neuroscience Discovery Biology, Janssen Research and Development, a Division of Janssen Pharmaceutica NV, Turnhoutseweg 30, B-2340 Beerse, Belgium
| | - Frederik Rombouts
- Neuroscience Medicinal Chemistry, Janssen Research and Development, a Division of Janssen Pharmaceutica NV, Turnhoutseweg 30, B-2340 Beerse, Belgium
| | - José Ignacio Andrés
- Discovery Sciences, Janssen Research and Development, a Division of Janssen-Cilag, Jarama 75, 45007 Toledo, Spain
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126
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Bernard-Gauthier V, Aliaga A, Aliaga A, Boudjemeline M, Hopewell R, Kostikov A, Rosa-Neto P, Thiel A, Schirrmacher R. Syntheses and evaluation of carbon-11- and fluorine-18-radiolabeled pan-tropomyosin receptor kinase (Trk) inhibitors: exploration of the 4-aza-2-oxindole scaffold as Trk PET imaging agents. ACS Chem Neurosci 2015; 6:260-76. [PMID: 25350780 DOI: 10.1021/cn500193f] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Tropomyosin receptor kinases (TrkA/B/C) are critically involved in the development of the nervous system, in neurological disorders as well as in multiple neoplasms of both neural and non-neural origins. The development of Trk radiopharmaceuticals would offer unique opportunities toward a more complete understanding of this emerging therapeutic target. To that end, we first developed [(11)C]GW441756 ([(11)C]9), a high affinity photoisomerizable pan-Trk inhibitor, as a lead radiotracer for our positron emission tomography (PET) program. Efficient carbon-11 radiolabeling afforded [(11)C]9 in high radiochemical yields (isolated RCY, 25.9% ± 5.7%). In vitro autoradiographic studies in rat brain and TrkB-expressing human neuroblastoma cryosections confirmed that [(11)C]9 specifically binds to Trk receptors in vitro. MicroPET studies revealed that binding of [(11)C]9 in the rodent brain was mostly nonspecific despite initial high brain uptake (SUVmax = 2.0). Modeling studies of the 4-aza-2-oxindole scaffold led to the successful identification of a small series of high affinity fluorinated and methoxy derivatized pan-Trk inhibitors based on our lead compound 9. Out of this series, the fluorinated compound 10 was selected for initial evaluation and radiolabeled with fluorine-18 (isolated RCY, 2.5% ± 0.6%). Compound [(18)F]10 demonstrated excellent Trk selectivity in a panel of cancer relevant kinase targets and a promising in vitro profile in tumors and brain sections but high oxidative metabolic susceptibility leading to nonspecific brain distribution in vivo. The information gained in this study will guide further exploration of the 4-aza-2-oxindole scaffold as a lead for Trk PET ligand development.
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Affiliation(s)
- Vadim Bernard-Gauthier
- Experimental
Medicine, Department of Medicine, McGill University, 1110 Pine
Avenue West, Montreal, Quebec H3A 1A3, Canada
- Department
of Oncology, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2, Canada
| | - Arturo Aliaga
- Translational
Neuroimaging Laboratory, McGill Centre for Studies in Aging, Douglas Mental Health University Institute, 6875 Boulevard LaSalle, Montreal, Quebec H4H 1R3, Canada
| | - Antonio Aliaga
- McConnell
Brain Imaging Centre, Montreal Neurological Institute, McGill University, 3801 University Street, Montreal, Quebec H3A 2B4, Canada
| | - Mehdi Boudjemeline
- McConnell
Brain Imaging Centre, Montreal Neurological Institute, McGill University, 3801 University Street, Montreal, Quebec H3A 2B4, Canada
| | - Robert Hopewell
- McConnell
Brain Imaging Centre, Montreal Neurological Institute, McGill University, 3801 University Street, Montreal, Quebec H3A 2B4, Canada
| | - Alexey Kostikov
- McConnell
Brain Imaging Centre, Montreal Neurological Institute, McGill University, 3801 University Street, Montreal, Quebec H3A 2B4, Canada
| | - Pedro Rosa-Neto
- Translational
Neuroimaging Laboratory, McGill Centre for Studies in Aging, Douglas Mental Health University Institute, 6875 Boulevard LaSalle, Montreal, Quebec H4H 1R3, Canada
| | - Alexander Thiel
- Department
of Neurology and Neurosurgery, McGill University, Jewish General Hospital, 3755 Cote St. Catherine Rd., Montreal, Quebec H2T 1E2, Canada
| | - Ralf Schirrmacher
- Department
of Oncology, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2, Canada
- McConnell
Brain Imaging Centre, Montreal Neurological Institute, McGill University, 3801 University Street, Montreal, Quebec H3A 2B4, Canada
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127
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Brahim M, Smari I, Ben Ammar H, Ben Hassine B, Soulé JF, Doucet H. Conditions for palladium-catalyzed direct arylations of 4-bromo and 4-iodo N-substituted pyrazoles without C–Br or C–I bond cleavage. Org Chem Front 2015. [DOI: 10.1039/c5qo00093a] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The Pd-catalyzed arylation at the C5 position ofN-protected pyrazole derivatives bearing bromo or iodo substituents at the C4 position is described.
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Affiliation(s)
- Mariem Brahim
- Institut des Sciences Chimiques de Rennes
- UMR 6226 CNRS-Université de Rennes 1 “Organométalliques
- Matériaux et Catalyse”
- 35042 Rennes
- France
| | - Imen Smari
- Institut des Sciences Chimiques de Rennes
- UMR 6226 CNRS-Université de Rennes 1 “Organométalliques
- Matériaux et Catalyse”
- 35042 Rennes
- France
| | - Hamed Ben Ammar
- Laboratoire de Synthèse Organique Asymétrique et Catalyse Homogène (UR 11ES56)
- Université de Monastir Faculté des Sciences de Monastir
- Monastir 5000
- Tunisia
| | - Bechir Ben Hassine
- Laboratoire de Synthèse Organique Asymétrique et Catalyse Homogène (UR 11ES56)
- Université de Monastir Faculté des Sciences de Monastir
- Monastir 5000
- Tunisia
| | - Jean-François Soulé
- Institut des Sciences Chimiques de Rennes
- UMR 6226 CNRS-Université de Rennes 1 “Organométalliques
- Matériaux et Catalyse”
- 35042 Rennes
- France
| | - Henri Doucet
- Institut des Sciences Chimiques de Rennes
- UMR 6226 CNRS-Université de Rennes 1 “Organométalliques
- Matériaux et Catalyse”
- 35042 Rennes
- France
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128
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Finnema SJ, Scheinin M, Shahid M, Lehto J, Borroni E, Bang-Andersen B, Sallinen J, Wong E, Farde L, Halldin C, Grimwood S. Application of cross-species PET imaging to assess neurotransmitter release in brain. Psychopharmacology (Berl) 2015; 232:4129-57. [PMID: 25921033 PMCID: PMC4600473 DOI: 10.1007/s00213-015-3938-6] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 04/09/2015] [Indexed: 01/03/2023]
Abstract
RATIONALE This review attempts to summarize the current status in relation to the use of positron emission tomography (PET) imaging in the assessment of synaptic concentrations of endogenous mediators in the living brain. OBJECTIVES Although PET radioligands are now available for more than 40 CNS targets, at the initiation of the Innovative Medicines Initiative (IMI) "Novel Methods leading to New Medications in Depression and Schizophrenia" (NEWMEDS) in 2009, PET radioligands sensitive to an endogenous neurotransmitter were only validated for dopamine. NEWMEDS work-package 5, "Cross-species and neurochemical imaging (PET) methods for drug discovery", commenced with a focus on developing methods enabling assessment of changes in extracellular concentrations of serotonin and noradrenaline in the brain. RESULTS Sharing the workload across institutions, we utilized in vitro techniques with cells and tissues, in vivo receptor binding and microdialysis techniques in rodents, and in vivo PET imaging in non-human primates and humans. Here, we discuss these efforts and review other recently published reports on the use of radioligands to assess changes in endogenous levels of dopamine, serotonin, noradrenaline, γ-aminobutyric acid, glutamate, acetylcholine, and opioid peptides. The emphasis is on assessment of the availability of appropriate translational tools (PET radioligands, pharmacological challenge agents) and on studies in non-human primates and human subjects, as well as current challenges and future directions. CONCLUSIONS PET imaging directed at investigating changes in endogenous neurochemicals, including the work done in NEWMEDS, have highlighted an opportunity to further extend the capability and application of this technology in drug development.
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Affiliation(s)
- Sjoerd J. Finnema
- />Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska Institutet, Stockholm, Sweden
| | - Mika Scheinin
- />Department of Pharmacology, Drug Development and Therapeutics, University of Turku, Turku, Finland , />Unit of Clinical Pharmacology, Turku University Hospital, Turku, Finland
| | - Mohammed Shahid
- />Research and Development, Orion Corporation, Orion Pharma, Turku, Finland
| | - Jussi Lehto
- />Department of Pharmacology, Drug Development and Therapeutics, University of Turku, Turku, Finland
| | - Edilio Borroni
- />Neuroscience Department, Hoffman-La Roche, Basel, Switzerland
| | | | - Jukka Sallinen
- />Research and Development, Orion Corporation, Orion Pharma, Turku, Finland
| | - Erik Wong
- />Neuroscience Innovative Medicine Unit, AstraZeneca, Wilmington, DE USA
| | - Lars Farde
- />Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska Institutet, Stockholm, Sweden , />Translational Science Center at Karolinska Institutet, AstraZeneca, Stockholm, Sweden
| | - Christer Halldin
- />Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska Institutet, Stockholm, Sweden
| | - Sarah Grimwood
- Neuroscience Research Unit, Pfizer Inc, Cambridge, MA, USA. .,, 610 Main Street, Cambridge, MA, 02139, USA.
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129
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Bernard-Gauthier V, Bailey JJ, Aliaga A, Kostikov A, Rosa-Neto P, Wuest M, Brodeur GM, Bedell BJ, Wuest F, Schirrmacher R. Development of subnanomolar radiofluorinated (2-pyrrolidin-1-yl)imidazo[1,2-b]pyridazine pan-Trk inhibitors as candidate PET imaging probes. MEDCHEMCOMM 2015. [DOI: 10.1039/c5md00388a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Dysregulation of tropomyosin receptor kinases (TrkA/B/C) expression and signalling is recognized as a hallmark of numerous neurodegenerative diseases including Parkinson's, Huntington's and Alzheimer's disease.
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Affiliation(s)
| | | | - Arturo Aliaga
- Translational Neuroimaging Laboratory
- McGill Centre for Studies in Aging
- Douglas Mental Health University Institute
- Montreal
- Canada
| | - Alexey Kostikov
- McConnell Brain Imaging Centre
- Montreal Neurological Institute
- McGill University
- Montreal
- Canada
| | - Pedro Rosa-Neto
- Translational Neuroimaging Laboratory
- McGill Centre for Studies in Aging
- Douglas Mental Health University Institute
- Montreal
- Canada
| | - Melinda Wuest
- Department of Oncology
- University of Alberta
- Edmonton
- Canada
| | | | - Barry J. Bedell
- Biospective Inc
- Montreal
- Canada
- Research Institute of the McGill University Health Centre
- Montreal
| | - Frank Wuest
- Department of Oncology
- University of Alberta
- Edmonton
- Canada
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130
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Barth V, Need A. Identifying novel radiotracers for PET imaging of the brain: application of LC-MS/MS to tracer identification. ACS Chem Neurosci 2014; 5:1148-53. [PMID: 24828747 DOI: 10.1021/cn500072r] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Nuclear medicine imaging biomarker applications are limited by the radiotracers available. Radiotracers enable the measurement of target engagement, or occupancy in relation to plasma exposure. These tracers can also be used as pharmacodynamic biomarkers to demonstrate functional consequences of binding a target. More recently, radiotracers have also been used for patient tailoring in Alzheimer's disease seen with amyloid imaging. Radiotracers for the central nervous system (CNS) are challenging to identify, as they require a unique intersection of multiple properties. Recent advances in tangential technologies, along with the use of iterative learning for the purposes of deriving in silico models, have opened up additional opportunities to identify radiotracers. Mass spectral technologies and in silico modeling have made it possible to measure and predict in vivo characteristics of molecules to indicate potential tracer performance. By analyzing these data alongside other measures, it is possible to delineate guidelines to increase the likelihood of selecting compounds that can perform as radiotracers or serve as the best starting point to develop a radiotracer following additional structural modification. The application of mass spectrometry based technologies is an efficient way to evaluate compounds as tracers in vivo, but more importantly enables the testing of potential tracers that have either no label site or complex labeling chemistry which may deter assessment by traditional means; therefore, use of this technology allows for more rapid iterative learning. The ability to differentially distribute toward target rich tissues versus tissue with no/less target present is a unique defining feature of a tracer. By testing nonlabeled compounds in vivo and analyzing tissue levels by LC-MS/MS, rapid assessment of a compound's ability to differentially distribute in a manner consistent with target expression biology guides the focus of chemistry resources for both designing and labeling tracer candidates. LC-MS/MS has only recently been used for de novo tracer identification; however, this connection of mass spectral technology to imaging has initiated engagement from a wider community that brings diverse backgrounds into the tracer discovery arena.
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Affiliation(s)
- Vanessa Barth
- Eli Lilly and Co., Lilly Research Laboratories, Indianapolis, Indiana 46285, United States
| | - Anne Need
- Eli Lilly and Co., Lilly Research Laboratories, Indianapolis, Indiana 46285, United States
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131
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Joshi EM, Need A, Schaus J, Chen Z, Benesh D, Mitch C, Morton S, Raub TJ, Phebus L, Barth V. Efficiency gains in tracer identification for nuclear imaging: can in vivo LC-MS/MS evaluation of small molecules screen for successful PET tracers? ACS Chem Neurosci 2014; 5:1154-63. [PMID: 25247893 DOI: 10.1021/cn500073j] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Positron emission tomography (PET) imaging has become a useful noninvasive technique to explore molecular biology within living systems; however, the utility of this method is limited by the availability of suitable radiotracers to probe specific targets and disease biology. Methods to identify potential areas of improvement in the ability to predict small molecule performance as tracers prior to radiolabeling would speed the discovery of novel tracers. In this retrospective analysis, we characterized the brain penetration or peak SUV (standardized uptake value), binding potential (BP), and brain exposure kinetics across a series of known, nonradiolabeled PET ligands using in vivo LC-MS/MS (liquid chromatography coupled to mass spectrometry) and correlated these parameters with the reported PET ligand performance in nonhuman primates and humans available in the literature. The PET tracers studied included those reported to label G protein-coupled receptors (GPCRs), intracellular enzymes, and transporters. Additionally, data for each tracer was obtained from a mouse brain uptake assay (MBUA), previously published, where blood-brain barrier (BBB) penetration and clearance parameters were assessed and compared against similar data collected on a broad compound set of central nervous system (CNS) therapeutic compounds. The BP and SUV identified via nonradiolabeled LC-MS/MS, while different from the published values observed in the literature PET tracer data, allowed for an identification of initial criteria values we sought to facilitate increased potential for success from our early discovery screening paradigm. Our analysis showed that successful, as well as novel, clinical PET tracers exhibited BP of greater than 1.5 and peak SUVs greater than approximately 150% at 5 min post dose in rodents. The brain kinetics appeared similar between both techniques despite differences in tracer dose, suggesting linearity across these dose ranges. The assessment of tracers in a CNS exposure model, the mouse brain uptake assessment (MBUA), showed that those compound with initial brain-to-plasma ratios >2 and unbound fraction in brain homogenate >0.01 were more likely to be clinically successful PET ligands. Taken together, early incorporation of a LC/MS/MS cold tracer discovery assay and a parallel MBUA can be an useful screening paradigm to prioritize and rank order potential novel PET radioligands during early tracer discovery efforts. Compounds considered for continued in vivo PET assessments can be identified quickly by leveraging in vitro affinity and selectivity measures, coupled with data from a MBUA, primarily the 5 min brain-to-plasma ratio and unbound fraction data. Coupled utilization of these data creates a strategy to efficiently screen for the identification of appropriate chemical space to invest in for radiotracer discovery.
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Affiliation(s)
- Elizabeth M. Joshi
- Eli Lilly and Co., Lilly Research Laboratories, Indianapolis, Indiana 46285, United States
| | - Anne Need
- Eli Lilly and Co., Lilly Research Laboratories, Indianapolis, Indiana 46285, United States
| | - John Schaus
- Eli Lilly and Co., Lilly Research Laboratories, Indianapolis, Indiana 46285, United States
| | - Zhaogen Chen
- Eli Lilly and Co., Lilly Research Laboratories, Indianapolis, Indiana 46285, United States
| | - Dana Benesh
- Eli Lilly and Co., Lilly Research Laboratories, Indianapolis, Indiana 46285, United States
| | - Charles Mitch
- Eli Lilly and Co., Lilly Research Laboratories, Indianapolis, Indiana 46285, United States
| | - Stuart Morton
- Eli Lilly and Co., Lilly Research Laboratories, Indianapolis, Indiana 46285, United States
| | - Thomas J. Raub
- Eli Lilly and Co., Lilly Research Laboratories, Indianapolis, Indiana 46285, United States
| | - Lee Phebus
- Eli Lilly and Co., Lilly Research Laboratories, Indianapolis, Indiana 46285, United States
| | - Vanessa Barth
- Eli Lilly and Co., Lilly Research Laboratories, Indianapolis, Indiana 46285, United States
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132
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Honer M, Gobbi L, Martarello L, Comley RA. Radioligand development for molecular imaging of the central nervous system with positron emission tomography. Drug Discov Today 2014; 19:1936-44. [DOI: 10.1016/j.drudis.2014.08.012] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Revised: 07/24/2014] [Accepted: 08/21/2014] [Indexed: 11/25/2022]
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133
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Hirabayashi H. What is the definitive role of DMPK research for successful drug discovery and development? Until now and in the future. Drug Metab Pharmacokinet 2014; 29:357-9. [PMID: 25345360 DOI: 10.2133/dmpk.dmpk-14-pf-905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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134
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Abstract
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Decades after its discovery, positron emission tomography (PET)
remains the premier tool for imaging neurochemistry in living humans.
Technological improvements in radiolabeling methods, camera design,
and image analysis have kept PET in the forefront. In addition, the
use of PET imaging has expanded because researchers have developed
new radiotracers that visualize receptors, transporters, enzymes,
and other molecular targets within the human brain. However,
of the thousands of proteins in the central nervous system
(CNS), researchers have successfully imaged fewer than 40 human proteins.
To address the critical need for new radiotracers, this Account expounds
on the decisions, strategies, and pitfalls of CNS radiotracer development
based on our current experience in this area. We discuss the
five key components of radiotracer development for
human imaging: choosing a biomedical question, selection of a biological
target, design of the radiotracer chemical structure, evaluation of
candidate radiotracers, and analysis of preclinical imaging. It is
particularly important to analyze the market of scientists or companies
who might use a new radiotracer and carefully select a relevant biomedical
question(s) for that audience. In the selection of a specific biological
target, we emphasize how target localization and identity can constrain
this process and discuss the optimal target density and affinity ratios
needed for binding-based radiotracers. In addition, we discuss various
PET test–retest variability requirements for monitoring changes
in density, occupancy, or functionality for new radiotracers. In the synthesis of new radiotracer structures, high-throughput,
modular syntheses have proved valuable, and these processes provide
compounds with sites for late-stage radioisotope installation. As
a result, researchers can manage the time constraints associated with
the limited half-lives of isotopes. In order to evaluate brain uptake,
a number of methods are available to predict bioavailability, blood–brain
barrier (BBB) permeability, and the associated issues of nonspecific
binding and metabolic stability. To evaluate the synthesized chemical
library, researchers need to consider high-throughput affinity assays,
the analysis of specific binding, and the importance of fast binding
kinetics. Finally, we describe how we initially assess preclinical
radiotracer imaging, using brain uptake, specific binding, and preliminary
kinetic analysis to identify promising radiotracers that may be useful
for human brain imaging. Although we discuss these five design components
separately and linearly in this Account, in practice we develop new
PET-based radiotracers using these design components nonlinearly and
iteratively to develop new compounds in the most efficient way possible.
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Affiliation(s)
- Genevieve C. Van de Bittner
- Athinoula
A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129, United States
| | - Emily L. Ricq
- Athinoula
A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129, United States
- Department
of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Jacob M. Hooker
- Athinoula
A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129, United States
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135
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Abstract
Single photon emission computed tomography (SPECT) or positron emission computed tomography (PET) imaging agents for neurodegenerative diseases have a significant impact on clinical diagnosis and patient care. The examples of Parkinson's Disease (PD) and Alzheimer's Disease (AD) imaging agents described in this paper provide a general view on how imaging agents, i.e. radioactive drugs, are selected, chemically prepared and applied in humans. Imaging the living human brain can provide unique information on the pathology and progression of neurodegenerative diseases, such as AD and PD. The imaging method will also facilitate preclinical and clinical trials of new drugs offering specific information related to drug binding sites in the brain. In the future, chemists will continue to play important roles in identifying specific targets, synthesizing target-specific probes for screening and ultimately testing them by in vitro and in vivo assays.
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Affiliation(s)
- Lin Zhu
- Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China.
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136
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Zhang L, Drummond E, Brodney MA, Cianfrogna J, Drozda SE, Grimwood S, Vanase-Frawley MA, Villalobos A. Design, synthesis and evaluation of [(3)H]PF-7191, a highly specific nociceptin opioid peptide (NOP) receptor radiotracer for in vivo receptor occupancy (RO) studies. Bioorg Med Chem Lett 2014; 24:5219-23. [PMID: 25442316 DOI: 10.1016/j.bmcl.2014.09.069] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 09/19/2014] [Accepted: 09/24/2014] [Indexed: 11/26/2022]
Abstract
Herein we report the identification of (+)-N-(2-((1H-pyrazol-1-yl)methyl)-3-((1R,3r,5S)-6'-fluoro-8-azaspiro[bicyclo[3.2.1]octane-3,1'-isochroman]-8-yl)propyl)-N-[(3)H]-methylacetamide {[(3)H]PF-7191 [(+)-11]} as a promising radiotracer for the nociceptin opioid peptide (NOP) receptor. (+)-11 demonstrated high NOP binding affinity (Ki = 0.1 nM), excellent selectivity over other opioid receptors (>1000×) and good brain permeability in rats (C(b,u)/C(p,u) = 0.29). Subsequent characterization of [(3)H](+)-11 showed a high level of specific binding and a brain bio-distribution pattern consistent with known NOP receptor expression. Furthermore, the in vivo brain binding of [(3)H](+)-11 in rats was inhibited by a selective NOP receptor antagonist in a dose-responsive manner. This overall favorable profile indicated that [(3)H](+)-11 is a robust radiotracer for pre-clinical in vivo receptor occupancy (RO) measurements and a possible substrate for carbon-11 labeling for positron emission tomography (PET) imaging in higher species.
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Affiliation(s)
- Lei Zhang
- Neuroscience Medicinal Chemistry, Pfizer Inc., Cambridge, MA 02139, USA.
| | - Elena Drummond
- Neuroscience Research Unit, Pfizer Inc., Cambridge, MA 02139, USA
| | - Michael A Brodney
- Neuroscience Medicinal Chemistry, Pfizer Inc., Cambridge, MA 02139, USA
| | - Julie Cianfrogna
- Pharmacokinetics, Dynamics and Metabolism, Pfizer Inc., Groton, CT 06340, USA
| | - Susan E Drozda
- Neuroscience Medicinal Chemistry, Pfizer Inc., Groton, CT 06340, USA
| | - Sarah Grimwood
- Neuroscience Research Unit, Pfizer Inc., Cambridge, MA 02139, USA
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137
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5-(4-((4-[18F]fluorobenzyl)oxy)-3-methoxybenzyl)pyrimidine-2,4-diamine: A selective dual inhibitor for potential PET imaging of Trk/CSF-1R. Bioorg Med Chem Lett 2014; 24:4784-90. [DOI: 10.1016/j.bmcl.2014.09.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Revised: 09/02/2014] [Accepted: 09/03/2014] [Indexed: 12/14/2022]
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138
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Fridén M, Wennerberg M, Antonsson M, Sandberg-Ställ M, Farde L, Schou M. Identification of positron emission tomography (PET) tracer candidates by prediction of the target-bound fraction in the brain. EJNMMI Res 2014; 4:50. [PMID: 26116114 PMCID: PMC4452637 DOI: 10.1186/s13550-014-0050-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 09/07/2014] [Indexed: 11/13/2022] Open
Abstract
Background Development of tracers for imaging with positron emission tomography (PET) is often a time-consuming process associated with considerable attrition. In an effort to simplify this process, we herein propose a mechanistically integrated approach for the selection of tracer candidates based on in vitro measurements of ligand affinity (Kd), non-specific binding in brain tissue (Vu,brain), and target protein expression (Bmax). Methods A dataset of 35 functional and 12 non-functional central nervous system (CNS) PET tracers was compiled. Data was identified in literature for Kd and Bmax, whereas a brain slice methodology was used to determine values for Vu,brain. A mathematical prediction model for the target-bound fraction of tracer in the brain (ftb) was derived and evaluated with respect to how well it predicts tracer functionality compared to traditional PET tracer candidate selection criteria. Results The methodology correctly classified 31/35 functioning and 12/12 non-functioning tracers. This predictivity was superior to traditional classification criteria or combinations thereof. Conclusions The presented CNS PET tracer identification approach is rapid and accurate and is expected to facilitate the development of novel PET tracers for the molecular imaging community. Electronic supplementary material The online version of this article (doi:10.1186/s13550-014-0050-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Markus Fridén
- Respiratory Inflammation and Autoimmunity Innovative Medicines, AstraZeneca R&D, Mölndal, Sweden,
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139
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Piel M, Vernaleken I, Rösch F. Positron Emission Tomography in CNS Drug Discovery and Drug Monitoring. J Med Chem 2014; 57:9232-58. [DOI: 10.1021/jm5001858] [Citation(s) in RCA: 111] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Markus Piel
- Institute
of Nuclear Chemistry, Johannes Gutenberg-University, Fritz-Strassmann-Weg 2, D-55128 Mainz, Germany
| | - Ingo Vernaleken
- Department
of Psychiatry, Psychotherapy, and Psychosomatics, RWTH Aachen University, Pauwelsstraße 30, D-52074 Aachen, Germany
| | - Frank Rösch
- Institute
of Nuclear Chemistry, Johannes Gutenberg-University, Fritz-Strassmann-Weg 2, D-55128 Mainz, Germany
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140
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Kehler J, Kilburn JP, Estrada S, Christensen SR, Wall A, Thibblin A, Lubberink M, Bundgaard C, Brennum LT, Steiniger-Brach B, Christoffersen CT, Timmermann S, Kreilgaard M, Antoni G, Bang-Andersen B, Nielsen J. Discovery and development of 11C-Lu AE92686 as a radioligand for PET imaging of phosphodiesterase10A in the brain. J Nucl Med 2014; 55:1513-8. [PMID: 24994928 DOI: 10.2967/jnumed.114.140178] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED Phosphodiesterase 10A (PDE10A) plays a key role in the regulation of brain striatal signaling, and several pharmaceutical companies currently investigate PDE10A inhibitors in clinical trials for various central nervous system diseases. A PDE10A PET ligand may provide evidence that a clinical drug candidate reaches and binds to the target. Here we describe the successful discovery and initial validation of the novel radiolabeled PDE10A ligand 5,8-dimethyl-2-[2-((1-(11)C-methyl)-4-phenyl-1H-imidazol-2-yl)-ethyl]-[1,2,4]triazolo[1,5-a]pyridine ((11)C-Lu AE92686) and its tritiated analog (3)H-Lu AE92686. METHODS Initial in vitro experiments suggested Lu AE92686 as a promising radioligand, and the corresponding tritiated and (11)C-labeled compounds were synthesized. (3)H-Lu AE92686 was evaluated as a ligand for in vivo occupancy studies in mice and rats, and (11)C-Lu AE92686 was evaluated as a PET tracer candidate in cynomolgus monkeys and in humans. RESULTS (11)C-Lu AE92686 displayed high specificity and selectivity for PDE10A-expressing regions in the brain of cynomolgus monkeys and humans. Similar results were found in rodents using (3)H-Lu AE92686. The binding of (11)C-Lu AE92686 and (3)H-Lu AE92686 to striatum was completely and dose-dependently blocked by the structurally different PDE10A inhibitor 2-[4-(1-methyl-4-pyridin-4-yl-1H-pyrazol-3-yl)-phenoxymethyl]-quinoline (MP-10) in rodents and in monkeys. In all species, specific binding of the radioligand was seen in the striatum but not in the cerebellum, supporting the use of the cerebellum as a reference region. The binding potentials (BPND) of (11)C-Lu AE92686 in the striatum of both cynomolgus monkeys and humans were evaluated by the simplified reference tissue model with the cerebellum as the reference tissue, and BPND was found to be high and reproducible-that is, BPNDs were 6.5 ± 0.3 (n = 3) and 7.5 ± 1.0 (n = 12) in monkeys and humans, respectively. CONCLUSION Rodent, monkey, and human tests of labeled Lu AE92686 suggest that (11)C-Lu AE92686 has great potential as a human PET tracer for the PDE10A enzyme.
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Affiliation(s)
- Jan Kehler
- Division of Discovery Chemistry and DMPK, H. Lundbeck A/S, Valby, Denmark
| | - John Paul Kilburn
- Division of Discovery Chemistry and DMPK, H. Lundbeck A/S, Valby, Denmark
| | - Sergio Estrada
- Preclinical PET Platform, Department of Medicinal Chemistry, Uppsala University, Uppsala, Sweden
| | | | - Anders Wall
- Nuclear Medicine and PET, Uppsala University and Uppsala University Hospital, Uppsala, Sweden
| | - Alf Thibblin
- Preclinical PET Platform, Department of Medicinal Chemistry, Uppsala University, Uppsala, Sweden
| | - Mark Lubberink
- Nuclear Medicine and PET, Uppsala University and Uppsala University Hospital, Uppsala, Sweden
| | | | | | | | | | - Stine Timmermann
- Department of Quantitative Pharmacology, H. Lundbeck A/S, Valby, Denmark; and
| | - Mads Kreilgaard
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Gunnar Antoni
- Preclinical PET Platform, Department of Medicinal Chemistry, Uppsala University, Uppsala, Sweden
| | - Benny Bang-Andersen
- Division of Discovery Chemistry and DMPK, H. Lundbeck A/S, Valby, Denmark Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Jacob Nielsen
- Division of Synaptic Transmission, H. Lundbeck A/S, Valby, Denmark
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141
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am Ende CW, Kormos BL, Humphrey JM. The State of the Art in Selective PDE2A Inhibitor Design. ACTA ACUST UNITED AC 2014. [DOI: 10.1002/9783527682348.ch06] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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142
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Guo Q, Owen DR, Rabiner EA, Turkheimer FE, Gunn RN. A graphical method to compare the in vivo binding potential of PET radioligands in the absence of a reference region: application to [¹¹C]PBR28 and [¹⁸F]PBR111 for TSPO imaging. J Cereb Blood Flow Metab 2014; 34:1162-8. [PMID: 24736889 PMCID: PMC4083379 DOI: 10.1038/jcbfm.2014.65] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Revised: 02/03/2014] [Accepted: 03/18/2014] [Indexed: 01/03/2023]
Abstract
Positron emission tomography (PET) radioligands for a reversible central nervous system (CNS) demand a high specific to nonspecific signal characterized by the binding potential (BPND). The quantification of BPND requires the determination of the nondisplaceable binding usually derived from a reference region devoid of the target of interest. However, for many CNS targets, there is no valid reference region available. In such cases, the total volume of distribution (VT) is often used as the outcome measure, which includes both the specific and nonspecific binding signals. Here we present a graphical method that allows for direct comparison of the binding potential of ligands using the regional VT data alone via linear regression. The method was first validated using literature data for five serotonin transporter ligands, for which a reference region exists, and then applied to two second generation 18 kDa translocator protein radioligands, namely [(11)C]PBR28 and [(18)F]PBR111. The analysis determined that [(11)C]PBR28 had a higher BPND than [(18)F]PBR111.
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Affiliation(s)
- Qi Guo
- 1] Centre for Neuroimaging Sciences, Institute of Psychiatry, King's College London, London, UK [2] Imanova, Centre for Imaging Sciences, London, UK [3] Division of Brain Sciences, Department of Medicine, Imperial College London, London, UK
| | - David R Owen
- Division of Brain Sciences, Department of Medicine, Imperial College London, London, UK
| | - Eugenii A Rabiner
- 1] Centre for Neuroimaging Sciences, Institute of Psychiatry, King's College London, London, UK [2] Imanova, Centre for Imaging Sciences, London, UK
| | - Federico E Turkheimer
- Centre for Neuroimaging Sciences, Institute of Psychiatry, King's College London, London, UK
| | - Roger N Gunn
- 1] Imanova, Centre for Imaging Sciences, London, UK [2] Division of Brain Sciences, Department of Medicine, Imperial College London, London, UK [3] Department of Engineering Science, University of Oxford, Oxford, UK
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143
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Mercier J, Archen L, Bollu V, Carré S, Evrard Y, Jnoff E, Kenda B, Lallemand B, Michel P, Montel F, Moureau F, Price N, Quesnel Y, Sauvage X, Valade A, Provins L. Discovery of heterocyclic nonacetamide synaptic vesicle protein 2A (SV2A) ligands with single-digit nanomolar potency: opening avenues towards the first SV2A positron emission tomography (PET) ligands. ChemMedChem 2014; 9:693-8. [PMID: 24446373 DOI: 10.1002/cmdc.201300482] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Indexed: 11/10/2022]
Abstract
The role of the synaptic vesicle protein 2A (SV2A) protein, target of the antiepileptic drug levetiracetam, is still mostly unknown. Considering its potential to provide in vivo functional insights into the role of SV2A in epileptic patients, the development of an SV2A positron emission tomography (PET) tracer has been undertaken. Using a 3D pharmacophore model based on close analogues of levetiracetam, we report the rationale design of three heterocyclic non-acetamide lead compounds, UCB-A, UCB-H and UCB-J, the first single-digit nanomolar SV2A ligands with suitable properties for development as PET tracers.
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Affiliation(s)
- Joël Mercier
- Global Chemistry, UCB NewMedicines, UCB Pharma, Chemin du Foriest, B-1420 Braine-L'Alleud (Belgium).
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144
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Ballatore C, Smith AB, Lee VMY, Trojanowski JQ, Brunden KR. Aminothienopyridazines as imaging probes of tau pathology: a patent evaluation of WO2013090497. Expert Opin Ther Pat 2014; 24:355-60. [PMID: 24387030 DOI: 10.1517/13543776.2014.871526] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Small-molecule ligands, amenable to positron emission tomography (PET) imaging of different types of neurodegenerative disease-associated amyloid deposits in the CNS of living patients, hold considerable promise for diagnostic purposes, as well as for monitoring disease progression and the effectiveness of treatments. The patent entitled 'Heterocyclic Compounds as Imaging Probes of Tau Pathology' (WO2013090497) discloses the identification of a novel class of tau imaging agents, the aminothienopyridazines. Selected compounds from this class are described that can stain selectively tau pathology in brain tissue sections. Moreover, examples of this class of compounds exhibit absorption, distribution, metabolism, excretion and pharmacokinetics (ADME-PK) properties that are appropriate for CNS PET ligands.
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Affiliation(s)
- Carlo Ballatore
- University of Pennsylvania, Perelman School of Medicine, Center for Neurodegenerative Disease Research , 3600 Spruce Street, Philadelphia, PA 19104-6323 , USA
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145
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Herth MM, Leth-Petersen S, Lehel S, Hansen M, Knudsen GM, Gillings N, Madsen J, Kristensen JL. Accelerating preclinical PET-screening: reductive amination with [11C]methoxybenzaldehydes. RSC Adv 2014. [DOI: 10.1039/c4ra02506g] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
We report, herein, a simple and efficient labelling strategy for multiple PET tracer preparation using a common intermediate, which has the potential to accelerate preclinical PET radiotracer screening.
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Affiliation(s)
- Matthias M. Herth
- PET and Cyclotron Unit
- Copenhagen University Hospital Rigshospitalet
- DK-2100 Copenhagen, Denmark
- Department of Drug Design and Pharmacology
- Faculty of Health and Medical Sciences
| | - Sebastian Leth-Petersen
- Department of Drug Design and Pharmacology
- Faculty of Health and Medical Sciences
- University of Copenhagen
- DK-2100 Copenhagen, Denmark
| | - Szabolcs Lehel
- PET and Cyclotron Unit
- Copenhagen University Hospital Rigshospitalet
- DK-2100 Copenhagen, Denmark
| | - Martin Hansen
- Department of Drug Design and Pharmacology
- Faculty of Health and Medical Sciences
- University of Copenhagen
- DK-2100 Copenhagen, Denmark
| | - Gitte M. Knudsen
- Center for Integrated Molecular Brain Imaging
- Rigshospitalet and University of Copenhagen
- DK-2100 Copenhagen, Denmark
| | - Nic Gillings
- PET and Cyclotron Unit
- Copenhagen University Hospital Rigshospitalet
- DK-2100 Copenhagen, Denmark
| | - Jacob Madsen
- PET and Cyclotron Unit
- Copenhagen University Hospital Rigshospitalet
- DK-2100 Copenhagen, Denmark
| | - Jesper L. Kristensen
- Department of Drug Design and Pharmacology
- Faculty of Health and Medical Sciences
- University of Copenhagen
- DK-2100 Copenhagen, Denmark
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146
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Hortala L, Arnaud J, Roux P, Oustric D, Boulu L, Oury-Donat F, Avenet P, Rooney T, Alagille D, Barret O, Tamagnan G, Barth F. Synthesis and preliminary evaluation of a new fluorine-18 labelled triazine derivative for PET imaging of cannabinoid CB2 receptor. Bioorg Med Chem Lett 2014; 24:283-7. [DOI: 10.1016/j.bmcl.2013.11.023] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Revised: 11/08/2013] [Accepted: 11/10/2013] [Indexed: 01/26/2023]
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147
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PDE2 inhibition: Potential for the treatment of cognitive disorders. Bioorg Med Chem Lett 2013; 23:6522-7. [DOI: 10.1016/j.bmcl.2013.10.014] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 10/03/2013] [Accepted: 10/06/2013] [Indexed: 01/21/2023]
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148
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Gao Y, Kellar KJ, Yasuda RP, Tran T, Xiao Y, Dannals RF, Horti AG. Derivatives of dibenzothiophene for positron emission tomography imaging of α7-nicotinic acetylcholine receptors. J Med Chem 2013; 56:7574-89. [PMID: 24050653 DOI: 10.1021/jm401184f] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
A new series of derivatives of 3-(1,4-diazabicyclo[3.2.2]nonan-4-yl)dibenzo[b,d]thiophene 5,5-dioxide with high binding affinities and selectivity for α7-nicotinic acetylcholine receptors (α7-nAChRs) (Ki = 0.4-20 nM) has been synthesized for positron emission tomography (PET) imaging of α7-nAChRs. Two radiolabeled members of the series [(18)F]7a (Ki = 0.4 nM) and [(18)F]7c (Ki = 1.3 nM) were synthesized. [(18)F]7a and [(18)F]7c readily entered the mouse brain and specifically labeled α7-nAChRs. The α7-nAChR selective ligand 1 (SSR180711) blocked the binding of [(18)F]7a in the mouse brain in a dose-dependent manner. The mouse blocking studies with non-α7-nAChR central nervous system drugs demonstrated that [(18)F]7a is highly α7-nAChR selective. In agreement with its binding affinity the binding potential of [(18)F]7a (BPND = 5.3-8.0) in control mice is superior to previous α7-nAChR PET radioligands. Thus, [(18)F]7a displays excellent imaging properties in mice and has been chosen for further evaluation as a potential PET radioligand for imaging of α7-nAChR in non-human primates.
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Affiliation(s)
- Yongjun Gao
- Russell H. Morgan Department of Radiology and Radiological Sciences, Division of Nuclear Medicine, The Johns Hopkins University School of Medicine , 600 North Wolfe Street, Baltimore, Maryland 21287-0816, United States
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