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Ahmed H, Wang Y, Griffiths WJ, Levey AI, Pikuleva I, Liang SH, Haider A. Brain cholesterol and Alzheimer's disease: challenges and opportunities in probe and drug development. Brain 2024; 147:1622-1635. [PMID: 38301270 PMCID: PMC11068113 DOI: 10.1093/brain/awae028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2023] [Revised: 12/20/2023] [Accepted: 01/13/2024] [Indexed: 02/03/2024] Open
Abstract
Cholesterol homeostasis is impaired in Alzheimer's disease; however, attempts to modulate brain cholesterol biology have not translated into tangible clinical benefits for patients to date. Several recent milestone developments have substantially improved our understanding of how excess neuronal cholesterol contributes to the pathophysiology of Alzheimer's disease. Indeed, neuronal cholesterol was linked to the formation of amyloid-β and neurofibrillary tangles through molecular pathways that were recently delineated in mechanistic studies. Furthermore, remarkable advances in translational molecular imaging have now made it possible to probe cholesterol metabolism in the living human brain with PET, which is an important prerequisite for future clinical trials that target the brain cholesterol machinery in Alzheimer's disease patients-with the ultimate aim being to develop disease-modifying treatments. This work summarizes current concepts of how the biosynthesis, transport and clearance of brain cholesterol are affected in Alzheimer's disease. Further, current strategies to reverse these alterations by pharmacotherapy are critically discussed in the wake of emerging translational research tools that support the assessment of brain cholesterol biology not only in animal models but also in patients with Alzheimer's disease.
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Affiliation(s)
- Hazem Ahmed
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, Yale University, New Haven, CT 06510, USA
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Institute of Pharmaceutical Sciences ETH, 8093 Zurich, Switzerland
| | - Yuqin Wang
- Institute of Life Science, Swansea University Medical School, Swansea SA2 8PP, UK
| | - William J Griffiths
- Institute of Life Science, Swansea University Medical School, Swansea SA2 8PP, UK
| | - Allan I Levey
- Department of Neurology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Irina Pikuleva
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Steven H Liang
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Ahmed Haider
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA 30322, USA
- Department of Radiology, Division of Nuclear Medicine and Molecular Imaging Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
- Department of Nuclear Medicine, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland
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2
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Ibrahimy A, Hoye J, Wu H, de Laat B, Kim SJ, Wilson DL, Morris ED. SLIC-Occ: functional segmentation of occupancy images improves precision of EC 50 images. EJNMMI Phys 2023; 10:80. [PMID: 38079001 PMCID: PMC10713928 DOI: 10.1186/s40658-023-00600-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 11/28/2023] [Indexed: 03/13/2024] Open
Abstract
BACKGROUND Drug occupancy studies with positron emission tomography imaging are used routinely in early phase drug development trials. Recently, our group introduced the Lassen Plot Filter, an extended version of the standard Lassen plot to estimate voxel-level occupancy images. Occupancy images can be used to create an EC50 image by applying an Emax model at each voxel. Our goal was to apply functional clustering of occupancy images via a clustering algorithm and produce a more precise EC50 image while maintaining accuracy. METHOD A digital brain phantom was used to create 10 occupancy images (corresponding to 10 different plasma concentrations of drug) that correspond to a ground truth EC50 image containing two bilateral local "hot spots" of high EC50 (region-1: 25; region-2: 50; background: 6-10 ng/mL). Maximum occupancy was specified as 0.85. An established noise model was applied to the simulated occupancy images and the images were smoothed. Simple Linear Iterative Clustering, an existing k-means clustering algorithm, was modified to segment a series of occupancy images into K clusters (which we call "SLIC-Occ"). EC50 images were estimated by nonlinear estimation at each cluster (post SLIC-Occ) and voxel (no clustering). Coefficient of variation images were estimated at each cluster and voxel, respectively. The same process was also applied to human occupancy data produced for a previously published study. RESULTS Variability in EC50 estimates was reduced by more than 80% in the phantom data after application of SLIC-Occ to occupancy images with only minimal loss of accuracy. A similar, but more modest improvement was achieved in variability when SLIC-Occ was applied to human occupancy images. CONCLUSIONS Our results suggest that functional segmentation of occupancy images via SLIC-Occ could produce more precise EC50 images and improve our ability to identify local "hot spots" of high effective affinity of a drug for its target(s).
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Affiliation(s)
- Alaaddin Ibrahimy
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA.
| | - Jocelyn Hoye
- Department of Radiology, Yale University, New Haven, CT, USA
| | - Hao Wu
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
| | - Bart de Laat
- Department of Psychiatry, Yale University, New Haven, CT, USA
| | - Su Jin Kim
- Department of Nuclear Medicine, Seoul National University Budang Hospital, Seongnam, South Korea
| | - David L Wilson
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
| | - Evan D Morris
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
- Department of Radiology, Yale University, New Haven, CT, USA
- Department of Psychiatry, Yale University, New Haven, CT, USA
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3
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Yoo CH, DuBois JM, Wang L, Tang Y, Hou L, Xu H, Chen J, Liang SH, Izquierdo-Garcia D, Wey HY. Preliminary Exploration of Pseudo-CT-Based Attenuation Correction for Simultaneous PET/MRI Brain Imaging in Nonhuman Primates. ACS OMEGA 2023; 8:45438-45446. [PMID: 38075761 PMCID: PMC10702200 DOI: 10.1021/acsomega.3c04824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 09/14/2023] [Indexed: 02/12/2024]
Abstract
This study aimed to develop a template-based attenuation correction (AC) for the nonhuman primate (NHP) brain. We evaluated the effects of AC on positron emission tomography (PET) data quantification with two experimental paradigms by comparing the quantitative outcomes obtained using a segmentation-based AC versus template-based AC. Population-based atlas was generated from ten adult rhesus macaques. Bolus experiments using [18F]PF-06455943 and a bolus-infusion experiment using [11C]OMAR were performed on a 3T Siemens PET/magnetic resonance-imaging (MRI). PET data were reconstructed with either μ map obtained from the segmentation-based AC or template-based AC. The standard uptake value (SUV), volume of distribution (VT), or percentage occupancy of rimonabant were calculated for [18F]PF-06455943 and [11C]OMAR PET, respectively. The leave-one-out cross-validation showed that the absolute percentage differences were 2.54 ± 2.86% for all region of interests. The segmentation-based AC had a lower SUV and VT (∼10%) of [18F]PF-06455943 than the template-based method. The estimated occupancy was higher in the template-based method compared to the segmentation-based AC in the bolus-infusion study. However, future studies may be needed if a different reference tissue is selected for data quantification. Our template-based AC approach was successfully developed and applied to the NHP brain. One limitation of this study was that validation was performed by comparing two different MR-based AC approaches without validating against AC methods based on computed tomography (CT).
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Affiliation(s)
- Chi-Hyeon Yoo
- Athinoula
A. Martinos Center for Biomedical Imaging, Department of Radiology,
Massachusetts General Hospital, Harvard
Medical School, Charlestown 02129, United States
| | - Jonathan M. DuBois
- Athinoula
A. Martinos Center for Biomedical Imaging, Department of Radiology,
Massachusetts General Hospital, Harvard
Medical School, Charlestown 02129, United States
| | - Lu Wang
- Department
of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Yongjin Tang
- Department
of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Lu Hou
- Department
of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Hao Xu
- Department
of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Jiahui Chen
- Division
of Nuclear Medicine and Molecular Imaging, Center for Advanced Medical
Imaging Sciences, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, United States
| | - Steven H. Liang
- Division
of Nuclear Medicine and Molecular Imaging, Center for Advanced Medical
Imaging Sciences, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, United States
| | - David Izquierdo-Garcia
- Athinoula
A. Martinos Center for Biomedical Imaging, Department of Radiology,
Massachusetts General Hospital, Harvard
Medical School, Charlestown 02129, United States
- Harvard–MIT
Division of Health Sciences and Technology, Cambridge, Massachusetts 02139, United States
- Bioengineering
Department, Universidad Carlos III de Madrid, Madrid 28911, Spain
| | - Hsiao-Ying Wey
- Athinoula
A. Martinos Center for Biomedical Imaging, Department of Radiology,
Massachusetts General Hospital, Harvard
Medical School, Charlestown 02129, United States
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Laurell GL, Plavén-Sigray P, Johansen A, Raval NR, Nasser A, Aabye Madsen C, Madsen J, Hansen HD, Donovan LL, Knudsen GM, Lammertsma AA, Ogden RT, Svarer C, Schain M. Kinetic models for estimating occupancy from single-scan PET displacement studies. J Cereb Blood Flow Metab 2023; 43:1544-1556. [PMID: 37070382 PMCID: PMC10414003 DOI: 10.1177/0271678x231168591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 03/01/2023] [Accepted: 03/05/2023] [Indexed: 04/19/2023]
Abstract
The traditional design of PET target engagement studies is based on a baseline scan and one or more scans after drug administration. We here evaluate an alternative design in which the drug is administered during an on-going scan (i.e., a displacement study). This approach results both in lower radiation exposure and lower costs. Existing kinetic models assume steady state. This condition is not present during a drug displacement and consequently, our aim here was to develop kinetic models for analysing PET displacement data. We modified existing compartment models to accommodate a time-variant increase in occupancy following the pharmacological in-scan intervention. Since this implies the use of differential equations that cannot be solved analytically, we developed instead one approximate and one numerical solution. Through simulations, we show that if the occupancy is relatively high, it can be estimated without bias and with good accuracy. The models were applied to PET data from six pigs where [11C]UCB-J was displaced by intravenous brivaracetam. The dose-occupancy relationship estimated from these scans showed good agreement with occupancies calculated with Lassen plot applied to baseline-block scans of two pigs. In summary, the proposed models provide a framework to determine target occupancy from a single displacement scan.
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Affiliation(s)
- Gjertrud Louise Laurell
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
- Faculty of Health and Medical Sciences, Copenhagen University, Copenhagen, Denmark
| | | | - Annette Johansen
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
- Faculty of Health and Medical Sciences, Copenhagen University, Copenhagen, Denmark
| | - Nakul Ravi Raval
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
- Faculty of Health and Medical Sciences, Copenhagen University, Copenhagen, Denmark
| | - Arafat Nasser
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
| | - Clara Aabye Madsen
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
- Faculty of Health and Medical Sciences, Copenhagen University, Copenhagen, Denmark
| | - Jacob Madsen
- Department of Clinical Physiology, Nuclear Medicine & PET, Copenhagen University, Copenhagen, Denmark
| | - Hanne Demant Hansen
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
- A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
| | - Lene Lundgaard Donovan
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
- Faculty of Health and Medical Sciences, Copenhagen University, Copenhagen, Denmark
| | - Gitte Moos Knudsen
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
- Faculty of Health and Medical Sciences, Copenhagen University, Copenhagen, Denmark
| | - Adriaan A Lammertsma
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - R Todd Ogden
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
- Molecular Imaging and Neuropathology Division, The New York State Psychiatric Institute, New York, USA
- Department of Biostatistics, Mailman School of Public Health, Columbia University, New York, USA
| | - Claus Svarer
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
| | - Martin Schain
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
- Antaros Medical, Mölndal, Sweden
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Matsunaga K, Tonomura M, Abe K, Shimosegawa E. Effect of scan-time shortening on the 11C-PHNO binding potential to dopamine D 3 receptor in humans and test-retest reliability. Ann Nucl Med 2023; 37:227-237. [PMID: 36656501 PMCID: PMC10060283 DOI: 10.1007/s12149-022-01819-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 12/23/2022] [Indexed: 01/20/2023]
Abstract
OBJECTIVE 11C-PHNO is a PET radioligand most specific to dopamine D3 receptor (D3R). The long scan duration of 120 min used in quantification of 11C-PHNO binding to D3R in previous studies is challenging to subjects. The main objective of this study was to investigate the effects of shorter scan times on the binding of 11C-PHNO to D3R and test-retest reliability using the latest digital whole-body PET system. METHODS Two 120-min 11C-PHNO brain scans were performed in 7 healthy subjects using a digital whole-body PET/CT. The binding potential relative to non-displaceable tracer in the tissue (BPND) of D3R-rich regions: the pallidum, ventral striatum (VST), substantia nigra (SN) and hypothalamus, were quantified using the simplified reference tissue model. The bias, correlation, and test-retest reliability of BPND, which includes the test-retest variability (TRV) and intraclass correlation coefficient (ICC), were evaluated and compared between scans of shorter durations (40-110 min post-injection) and the original 120-min scan acquisitions. RESULTS Progressively, shorter scan durations were associated with underestimation of BPND, slightly decreased correlation with 120-min derived BPND, and decrease in test-retest reliability. The BPND values of the pallidum, VST and SN from the shortened 90-min scans showed excellent correlation with those derived from the 120-min scans (determination coefficients > 0.98), and the bias within 5%. The test-retest reliability of BPND in these regions derived from 90-min scan (TRV of 3% in the VST and pallidum, 7% in the SN and the ICC exceeded 0.88) was comparable to those obtained in previous 120-min studies using brain-dedicated PET scanners. In the hypothalamus, the BPND values obtained from scan-time less than 110 min showed bias larger than 5% and the TRV more than 9%. CONCLUSION The scan-time shortening causes bias and decreasing test-retest reliability of 11C-PHNO BPND. However, in the whole-body PET system, 90-min scan duration was sufficient for estimating the 11C-PHNO BPND in the D3R-rich striatum and SN with small bias and at the test-retest reliability comparable to those derived from 120-min scans using the brain-dedicated PET systems.
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Affiliation(s)
- Keiko Matsunaga
- Department of Molecular Imaging in Medicine, Graduate School of Medicine, Osaka University, 2-1, Yamadaoka, Suita, Osaka, 565-0871, Japan.
| | - Misato Tonomura
- Department of Molecular Imaging in Medicine, Graduate School of Medicine, Osaka University, 2-1, Yamadaoka, Suita, Osaka, 565-0871, Japan
- Shionogi & Co., Ltd, 1-8, Doshomachi 3-Chome, Chuo-ku, Osaka, 541-0045, Japan
| | - Kohji Abe
- Department of Molecular Imaging in Medicine, Graduate School of Medicine, Osaka University, 2-1, Yamadaoka, Suita, Osaka, 565-0871, Japan
- Shionogi & Co., Ltd, 1-8, Doshomachi 3-Chome, Chuo-ku, Osaka, 541-0045, Japan
| | - Eku Shimosegawa
- Department of Molecular Imaging in Medicine, Graduate School of Medicine, Osaka University, 2-1, Yamadaoka, Suita, Osaka, 565-0871, Japan
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6
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Laurell GL, Plavén-Sigray P, Svarer C, Ogden RT, Knudsen GM, Schain M. Designing drug occupancy studies with PET neuroimaging: Sample size, occupancy ranges and analytical methods. Neuroimage 2022; 263:119620. [PMID: 36087903 DOI: 10.1016/j.neuroimage.2022.119620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 08/18/2022] [Accepted: 09/06/2022] [Indexed: 11/27/2022] Open
Abstract
Molecular neuroimaging is today considered essential for evaluation of novel CNS drugs; it is used to quantify blood-brain barrier permeability, verify interaction with key target and determine the drug dose resulting in 50% occupancy, IC50. In spite of this, there has been limited data available to inform on how to optimize study designs. Through simulations, we here evaluate how IC50 estimation is affected by the (i) range of drug doses administered, (ii) number of subjects included, and (iii) level of noise in the plasma drug concentration measurements. Receptor occupancy is determined from PET distribution volumes using two different methods: the Lassen plot and Likelihood estimation of occupancy (LEO). We also introduce and evaluate a new likelihood-based estimator for direct estimation of IC50 from PET distribution volumes. For estimation of IC50, we find very limited added benefit in scanning individuals who are given drug doses corresponding to less than 40% receptor occupancy. In the range of typical PET sample sizes (5-20 subjects) each extra individual clearly reduces the error of the IC50 estimate. In all simulations, likelihood-based methods gave more precise IC50 estimates than the Lassen plot; four times the number of subjects were required for the Lassen plot to reach the same IC50 precision as LEO.
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Affiliation(s)
- Gjertrud Louise Laurell
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, 6-8 Inge Lehmanns Vej, Rigshospitalet, Copenhagen DK-2100, Denmark; Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Pontus Plavén-Sigray
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, 6-8 Inge Lehmanns Vej, Rigshospitalet, Copenhagen DK-2100, Denmark
| | - Claus Svarer
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, 6-8 Inge Lehmanns Vej, Rigshospitalet, Copenhagen DK-2100, Denmark
| | - R Todd Ogden
- Department of Biostatistics, Columbia University, New York, NY, United States; Molecular Imaging and Neuropathology Area, New York State Psychiatric Institute, New York, NY, United States
| | - Gitte Moos Knudsen
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, 6-8 Inge Lehmanns Vej, Rigshospitalet, Copenhagen DK-2100, Denmark; Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Martin Schain
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, 6-8 Inge Lehmanns Vej, Rigshospitalet, Copenhagen DK-2100, Denmark; Antaros Medical AB, Mölndal, Sweden
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7
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Korde A, Mikolajczak R, Kolenc P, Bouziotis P, Westin H, Lauritzen M, Koole M, Herth MM, Bardiès M, Martins AF, Paulo A, Lyashchenko SK, Todde S, Nag S, Lamprou E, Abrunhosa A, Giammarile F, Decristoforo C. Practical considerations for navigating the regulatory landscape of non-clinical studies for clinical translation of radiopharmaceuticals. EJNMMI Radiopharm Chem 2022; 7:18. [PMID: 35852679 PMCID: PMC9296747 DOI: 10.1186/s41181-022-00168-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 06/27/2022] [Indexed: 11/10/2022] Open
Abstract
Background The development of radiopharmaceuticals requires extensive evaluation before they can be applied in a diagnostic or therapeutic setting in Nuclear Medicine. Chemical, radiochemical, and pharmaceutical parameters must be established and verified to ensure the quality of these novel products.
Main body To provide supportive evidence for the expected human in vivo behaviour, particularly related to safety and efficacy, additional tests, often referred to as “non-clinical” or “preclinical” are mandatory. This document is an outcome of a Technical Meeting of the International Atomic Energy Agency. It summarises the considerations necessary for non-clinical studies to accommodate the regulatory requirements for clinical translation of radiopharmaceuticals. These considerations include non-clinical pharmacology, radiation exposure and effects, toxicological studies, pharmacokinetic modelling, and imaging studies. Additionally, standardisation of different specific clinical applications is discussed.
Conclusion This document is intended as a guide for radiopharmaceutical scientists, Nuclear Medicine specialists, and regulatory professionals to bring innovative diagnostic and therapeutic radiopharmaceuticals into the clinical evaluation process in a safe and effective way.
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Affiliation(s)
- Aruna Korde
- Department of Nuclear Sciences and Applications, International Atomic Energy Agency (IAEA), Vienna International Centre, PO Box 100, 1400, Vienna, Austria
| | - Renata Mikolajczak
- Radioisotope Centre POLATOM, National Centre for Nuclear Research, Andrzej Soltan 7, 05-400, Otwock, Poland
| | - Petra Kolenc
- Department of Nuclear Medicine, University Medical Centre Ljubljana, 1000, Ljubljana, Slovenia.,Faculty of Pharmacy, University of Ljubljana, 1000, Ljubljana, Slovenia
| | - Penelope Bouziotis
- National Centre for Scientific Research "Demokritos", Institute of Nuclear & Radiological Sciences and Technology, Energy & Safety, 15341, Athens, Greece
| | - Hadis Westin
- Department of Immunology, Genetics and Pathology, Ridgeview Instruments AB, Uppsala Universitet, Dag Hammarskjölds Väg 36A, 752 37, Uppsala, Sweden
| | - Mette Lauritzen
- Bruker BioSpin MRI GmbH, Rudolf-Plank-Str. 23, 76275, Ettlingen, Germany
| | - Michel Koole
- Nuclear Medicine and Molecular Imaging, Katholieke Universiteit Leuven, 3000, Louvain, Belgium
| | - Matthias Manfred Herth
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Jagtvej 160, 2100, Copenhagen, Denmark.,Department of Clinical Physiology, Nuclear Medicine and PET, Copenhagen University Hospital, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Manuel Bardiès
- Institut de Recherche en Cancérologie de Montpellier (IRCM), INSERM U1194, Institut Régional du Cancer de Montpellier (ICM), Université de Montpellier, 34298, Montpellier, France
| | - Andre F Martins
- Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center, Eberhard Karls University Tübingen, Röntgenweg 13/1, 72076, Tübingen, Germany.,Cluster of Excellence iFIT (EXC 2180) "Image-Guided and Functionally Instructed Tumor Therapies", University of Tübingen, Tübingen, Germany
| | - Antonio Paulo
- Centro de Ciências E Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Bobadela Lrs, Campus Tecnológico e Nuclear, Estrada Nacional 10, Km 139.7, 2695-066, Lisbon, Portugal
| | - Serge K Lyashchenko
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Sergio Todde
- Department of Medicine and Surgery, University of Milano-Bicocca, Tecnomed Foundation, Milan, Italy
| | - Sangram Nag
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, 171 76, Stockholm, Sweden
| | - Efthimis Lamprou
- Bioemtech, Lefkippos Attica Technology Park-N.C.S.R Demokritos, Athens, Greece
| | - Antero Abrunhosa
- ICNAS/CIBIT, Institute for Nuclear Sciences Applied to Health, University of Coimbra, Coimbra, Portugal
| | - Francesco Giammarile
- Department of Nuclear Sciences and Applications, International Atomic Energy Agency (IAEA), Vienna International Centre, PO Box 100, 1400, Vienna, Austria
| | - Clemens Decristoforo
- Department of Nuclear Medicine, Medical University Innsbruck, 6020, Innsbruck, Austria.
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8
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NRM 2021 Abstract Booklet. J Cereb Blood Flow Metab 2021; 41:11-309. [PMID: 34905986 PMCID: PMC8851538 DOI: 10.1177/0271678x211061050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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9
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Kimura Y, Takahata K, Shimazaki T, Kitamura S, Seki C, Ikoma Y, Ichise M, Kawamura K, Yamada M, Zhang MR, Higuchi M, Nishino I, Suhara T. Pharmacokinetic and pharmacodynamic assessment of histamine H 3 receptor occupancy by enerisant: a human PET study with a novel H 3 binding ligand, [ 11C]TASP457. Eur J Nucl Med Mol Imaging 2021; 49:1127-1135. [PMID: 34651222 DOI: 10.1007/s00259-021-05571-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 09/21/2021] [Indexed: 10/20/2022]
Abstract
PURPOSE Histamine H3 receptor antagonists and inverse agonists have been extensively developed to treat sleep-wake, neurocognitive, and allied disorders. However, potential adverse effects, including insomnia, hampered the clinical use of these drugs, possibly due to their persistent interaction with the target molecules. The purpose of the present study was to estimate the pharmacokinetics and pharmacodynamics of enerisant, a novel antagonist and inverse agonist for histamine H3 receptors. METHODS To measure the histamine H3 receptor occupancy by enerisant, positron emission tomography studies using [11C]TASP457, a specific radioligand for histamine H3 receptors, were performed in 12 healthy men at baseline and at 2 h after oral administration of enerisant hydrochloride. For three of these subjects, two additional scans were performed at 6 and 26 h after the administration. Relationships between the receptor occupancy by enerisant and its dose and plasma concentrations were then analyzed. RESULTS Administration of enerisant hydrochloride decreased the radioligand binding in a dose-dependent manner. The estimated receptor occupancy values at 2 h varied as a function of its dose or plasma concentration. The time course of the occupancy showed persistently high levels (> 85%) in the two subjects with higher doses (25 and 12.5 mg). The occupancy was also initially high at 2 h and 6 h with the lower dose of 5 mg, but it decreased to 69.7% at 26 h. CONCLUSION The target engagement of enerisant was demonstrated in the brains of living human subjects. The occupancy of histamine H3 receptors by enerisant at 2 h can be predicted by applying the plasma concentration of enerisant to Hill's plot. The preliminary time-course investigation showed persistently high brain occupancy with high doses of enerisant despite the decreasing plasma concentration of the drug. Five milligrams or less dose would be appropriate for the treatment for narcolepsy with initially high occupancy allowing for effective treatment of narcolepsy, and then the occupancy level would be expected to decrease to a level to avoid this drug's unwanted side effect of insomnia at night, although further research is warranted to confirm the statement since the expected decrease is based on the finding in one subject. TRIAL REGISTRATION This study was retrospectively registered with ClinicalTrials.gov (NCT04631276) on November 17, 2020.
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Affiliation(s)
- Yasuyuki Kimura
- Department of Functional Brain Imaging, Institute for Quantum Medical Science , National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, Chiba, 263-8555, Japan.,Department of Clinical and Experimental Neuroimaging, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, 7-430 Morioka, Obu, Aichi, 474-8511, Japan
| | - Keisuke Takahata
- Department of Functional Brain Imaging, Institute for Quantum Medical Science , National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, Chiba, 263-8555, Japan
| | - Toshiharu Shimazaki
- Taisho Pharmaceutical Co, Ltd. 3-24-1 Takada, Toshima-ku, Tokyo, 170-8633, Japan
| | - Soichiro Kitamura
- Department of Functional Brain Imaging, Institute for Quantum Medical Science , National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, Chiba, 263-8555, Japan
| | - Chie Seki
- Department of Functional Brain Imaging, Institute for Quantum Medical Science , National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, Chiba, 263-8555, Japan
| | - Yoko Ikoma
- Department of Molecular Imaging and Theranostics, Institute for Quantum Medical Science , National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan
| | - Masanori Ichise
- Department of Functional Brain Imaging, Institute for Quantum Medical Science , National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, Chiba, 263-8555, Japan.,Department of Clinical and Experimental Neuroimaging, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, 7-430 Morioka, Obu, Aichi, 474-8511, Japan
| | - Kazunori Kawamura
- Department of Advanced Nuclear Medicine Sciences, Institute for Quantum Medical Science , National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage, Chiba, Chiba, 263-8555, Japan
| | - Makiko Yamada
- Department of Functional Brain Imaging, Institute for Quantum Medical Science , National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, Chiba, 263-8555, Japan
| | - Ming-Rong Zhang
- Department of Advanced Nuclear Medicine Sciences, Institute for Quantum Medical Science , National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage, Chiba, Chiba, 263-8555, Japan
| | - Makoto Higuchi
- Department of Functional Brain Imaging, Institute for Quantum Medical Science , National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, Chiba, 263-8555, Japan.
| | - Izumi Nishino
- Taisho Pharmaceutical Co, Ltd. 3-24-1 Takada, Toshima-ku, Tokyo, 170-8633, Japan
| | - Tetsuya Suhara
- Department of Functional Brain Imaging, Institute for Quantum Medical Science , National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, Chiba, 263-8555, Japan
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10
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de Laat B, Hoye J, Liu H, Morris ED. EC 50 images, a novel endpoint from PET target occupancy studies, reveal spatial variation in apparent drug affinity. Eur J Nucl Med Mol Imaging 2021; 49:1232-1241. [PMID: 34636937 DOI: 10.1007/s00259-021-05561-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 09/06/2021] [Indexed: 11/25/2022]
Abstract
PURPOSE We recently introduced voxel-level images of drug occupancy from PET via our "Lassen plot filter." Occupancy images revealed clear dependence of 11C-flumazenil displacement on dose of GABAa inhibitor, CVL-865, but with different scales in different brain regions. We hypothesized that regions requiring higher drug concentrations to achieve desired occupancy would have higher EC50 values. We introduce an "EC50 image" from human data to evaluate this hypothesis. METHODS Five healthy subjects were scanned with the nonselective GABAa tracer, 11C-flumazenil, before and (twice) after administration of CVL-865. We created ten occupancy images and applied an Emax model locally to create one EC50 image. We also performed simulations to confirm our observations of regional variation in EC50 and to identify the main source of variability in EC50. RESULTS As expected, the EC50 image revealed spatial variation in apparent drug affinity. High EC50 was found in areas of low occupancy for a given drug dose. Simulations demonstrated that sampling from an inadequate range of plasma drug concentrations could impair precision. CONCLUSION Our results argue for (a) confidence in the ability of the EC50 images to identify regional differences and (b) a need to tailor the range of drug doses in an occupancy study to regularize the precision of the EC50 throughout the brain. The EC50 image could add value to early-phase drug development by identifying regional variation in affinity that might impact therapy or safety and by guiding dose selection for later-phase trials.
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Affiliation(s)
- Bart de Laat
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA
| | - Jocelyn Hoye
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA
| | - Heather Liu
- Department of Biomedical Engineering, Yale University, CT, New Haven, USA
| | - Evan D Morris
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA.
- Department of Psychiatry, Yale University, New Haven, CT, USA.
- Department of Biomedical Engineering, Yale University, CT, New Haven, USA.
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11
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Placzek MS. Imaging Kappa Opioid Receptors in the Living Brain with Positron Emission Tomography. Handb Exp Pharmacol 2021; 271:547-577. [PMID: 34363128 DOI: 10.1007/164_2021_498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Kappa opioid receptor (KOR) neuroimaging using positron emission tomography (PET) has been immensely successful in all phases of discovery and validation in relation to radiotracer development from preclinical imaging to human imaging. There are now several KOR-specific PET radiotracers that can be utilized for neuroimaging, including agonist and antagonist ligands, as well as C-11 and F-18 variants. These technologies will increase KOR PET utilization by imaging centers around the world and have provided a foundation for future studies. In this chapter, I review the advances in KOR radiotracer discovery, focusing on ligands that have been translated into human imaging, and highlight key attributes unique to each KOR PET radiotracer. The utilization of these radiotracers in KOR PET neuroimaging can be subdivided into three major investigational classes: the first, measurement of KOR density; the second, measurement of KOR drug occupancy; the third, detecting changes in endogenous dynorphin following activation or deactivation. Given the involvement of the KOR/dynorphin system in a number of brain disorders including, but not limited to, pain, itch, mood disorders and addiction, measuring KOR density in the living brain will offer insight into the chronic effects of these disorders on KOR tone in humans. Notably, KOR PET has been successful at measuring drug occupancy in the human brain to guide dose selection for maximal therapeutic efficacy while avoiding harmful side effects. Lastly, we discuss the potential of KOR PET to detect changes in endogenous dynorphin in the human brain, to elucidate neural mechanisms and offer critical insight into disease-modifying therapeutics. We conclude with comments on other translational neuroimaging modalities such as MRI that could be used to study KOR-dynorphin tone in the living human brain.
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Affiliation(s)
- Michael S Placzek
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA. .,Department of Radiology, Harvard Medical School, Boston, MA, USA.
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12
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Sun J, Xiao Z, Haider A, Gebhard C, Xu H, Luo HB, Zhang HT, Josephson L, Wang L, Liang SH. Advances in Cyclic Nucleotide Phosphodiesterase-Targeted PET Imaging and Drug Discovery. J Med Chem 2021; 64:7083-7109. [PMID: 34042442 DOI: 10.1021/acs.jmedchem.1c00115] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Cyclic nucleotide phosphodiesterases (PDEs) control the intracellular concentrations of cAMP and cGMP in virtually all mammalian cells. Accordingly, the PDE family regulates a myriad of physiological functions, including cell proliferation, differentiation and apoptosis, gene expression, central nervous system function, and muscle contraction. Along this line, dysfunction of PDEs has been implicated in neurodegenerative disorders, coronary artery diseases, chronic obstructive pulmonary disease, and cancer development. To date, 11 PDE families have been identified; however, their distinct roles in the various pathologies are largely unexplored and subject to contemporary research efforts. Indeed, there is growing interest for the development of isoform-selective PDE inhibitors as potential therapeutic agents. Similarly, the evolving knowledge on the various PDE isoforms has channeled the identification of new PET probes, allowing isoform-selective imaging. This review highlights recent advances in PDE-targeted PET tracer development, thereby focusing on efforts to assess disease-related PDE pathophysiology and to support isoform-selective drug discovery.
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Affiliation(s)
- Jiyun Sun
- Department of Radiology, Division of Nuclear Medicine and Molecular Imaging Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, Massachusetts 02114, United States
| | - Zhiwei Xiao
- Department of Radiology, Division of Nuclear Medicine and Molecular Imaging Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, Massachusetts 02114, United States
| | - Ahmed Haider
- Department of Radiology, Division of Nuclear Medicine and Molecular Imaging Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, Massachusetts 02114, United States
| | - Catherine Gebhard
- Department of Nuclear Medicine, University Hospital Zurich, Raemistrasse 100, Zurich 8006, Switzerland.,Center for Molecular Cardiology, University of Zurich, Wagistrasse 12, Schlieren 8952, Switzerland
| | - Hao Xu
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, 613 West Huangpu Road, Tianhe District, Guangzhou 510630, China
| | - Hai-Bin Luo
- School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou 510006, China
| | - Han-Ting Zhang
- Departments of Neuroscience, Behavioral Medicine & Psychiatry, and Physiology & Pharmacology, the Rockefeller Neuroscience Institute, West Virginia University Health Sciences Center, Morgantown, West Virginia 26506, United States
| | - Lee Josephson
- Department of Radiology, Division of Nuclear Medicine and Molecular Imaging Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, Massachusetts 02114, United States
| | - Lu Wang
- Department of Radiology, Division of Nuclear Medicine and Molecular Imaging Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, Massachusetts 02114, United States.,Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, 613 West Huangpu Road, Tianhe District, Guangzhou 510630, China
| | - Steven H Liang
- Department of Radiology, Division of Nuclear Medicine and Molecular Imaging Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, Massachusetts 02114, United States
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13
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Li Q, Hou W, Li L, Su M, Ren Y, Wang W, Zou K, Tian R, Sun X. The use of systematic review evidence to support the development of guidelines for positron emission tomography: a cross-sectional survey. Eur Radiol 2021; 31:6992-7002. [PMID: 33683391 DOI: 10.1007/s00330-021-07756-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 01/06/2021] [Accepted: 02/04/2021] [Indexed: 02/05/2023]
Abstract
OBJECTIVES To examine to what degree guidelines for PET and PET/CT used systematic review evidence. METHODS The latest version of guidelines for PET, PET/CT or PET/MRI published in English in PubMed until December 2019 was analysed in two categories: (1) for indications, if mainly discussing the appropriate use of PET in diverse conditions; (2) for procedures, if providing step-by-step instructions for imaging. We surveyed the general characteristics and the use of systematic review evidence for developing recommendations across all guidelines, and surveyed the citation of evidence for five recommendation topics in guidelines for procedures. RESULTS Forty-seven guidelines, published between 2004 and 2020, were included. Guidelines for indications were developed mainly on systematic reviews (13 of 19, 68.4%). Among those, 12 (63.2%) reported the level of evidence, 4 (21.1%) reported the strength of recommendations, 3 (15.8%) described external review and 7 (36.8%) involved methodologists. Guidelines for procedures were seldom developed on systematic reviews (1 of 27, 3.7%). Among those, 1 (3.7%) reported the level of evidence, 1 (3.7%) reported the strength of recommendations, 3 (11.1%) described external review and 1 (3.7%) involved methodologists. Systematic review evidence was cited by 2 (7.4%) procedure guidelines per recommendation topic in median. CONCLUSION The use of systematic review evidence for developing recommendations among PET or PET/CT guidelines was suboptimal. While our survey is an icebreaking attempt to explore a key element (i.e. use of systematic review evidence) for developing nuclear medicine guidelines, assessments of other domains of guideline quality may help capture the entire picture. KEY POINTS • The use of systematic review evidence for developing recommendations among guidelines for PET or PET/CT was suboptimal. • Only 13 (68.4%) guidelines for indications and 1 (3.7%) guideline for procedures systematically reviewed the literature during guideline development. • For each recommendation topic we examined, only a median of 2 (7.4%) procedure guidelines cited systematic review evidence.
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Affiliation(s)
- Qianrui Li
- Department of Nuclear Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, China.,Chinese Evidence-based Medicine Centre, Cochrane China Centre and MAGIC China Centre, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Wenxiu Hou
- Department of Nuclear Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Ling Li
- Chinese Evidence-based Medicine Centre, Cochrane China Centre and MAGIC China Centre, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Minggang Su
- Department of Nuclear Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Yan Ren
- Chinese Evidence-based Medicine Centre, Cochrane China Centre and MAGIC China Centre, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Wen Wang
- Chinese Evidence-based Medicine Centre, Cochrane China Centre and MAGIC China Centre, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Kang Zou
- Chinese Evidence-based Medicine Centre, Cochrane China Centre and MAGIC China Centre, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Rong Tian
- Department of Nuclear Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
| | - Xin Sun
- Chinese Evidence-based Medicine Centre, Cochrane China Centre and MAGIC China Centre, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
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14
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Vissers MFJM, Heuberger JAAC, Groeneveld GJ. Targeting for Success: Demonstrating Proof-of-Concept with Mechanistic Early Phase Clinical Pharmacology Studies for Disease-Modification in Neurodegenerative Disorders. Int J Mol Sci 2021; 22:1615. [PMID: 33562713 PMCID: PMC7915613 DOI: 10.3390/ijms22041615] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 02/02/2021] [Accepted: 02/03/2021] [Indexed: 12/23/2022] Open
Abstract
The clinical failure rate for disease-modifying treatments (DMTs) that slow or stop disease progression has been nearly 100% for the major neurodegenerative disorders (NDDs), with many compounds failing in expensive and time-consuming phase 2 and 3 trials for lack of efficacy. Here, we critically review the use of pharmacological and mechanistic biomarkers in early phase clinical trials of DMTs in NDDs, and propose a roadmap for providing early proof-of-concept to increase R&D productivity in this field of high unmet medical need. A literature search was performed on published early phase clinical trials aimed at the evaluation of NDD DMT compounds using MESH terms in PubMed. Publications were selected that reported an early phase clinical trial with NDD DMT compounds between 2010 and November 2020. Attention was given to the reported use of pharmacodynamic (mechanistic and physiological response) biomarkers. A total of 121 early phase clinical trials were identified, of which 89 trials (74%) incorporated one or multiple pharmacodynamic biomarkers. However, only 65 trials (54%) used mechanistic (target occupancy or activation) biomarkers to demonstrate target engagement in humans. The most important categories of early phase mechanistic and response biomarkers are discussed and a roadmap for incorporation of a robust biomarker strategy for early phase NDD DMT clinical trials is proposed. As our understanding of NDDs is improving, there is a rise in potentially disease-modifying treatments being brought to the clinic. Further increasing the rational use of mechanistic biomarkers in early phase trials for these (targeted) therapies can increase R&D productivity with a quick win/fast fail approach in an area that has seen a nearly 100% failure rate to date.
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Affiliation(s)
- Maurits F. J. M. Vissers
- Centre for Human Drug Research, Zernikedreef 8, 2333 CL Leiden, The Netherlands; (J.A.A.C.H.); (G.J.G.)
- Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - Jules A. A. C. Heuberger
- Centre for Human Drug Research, Zernikedreef 8, 2333 CL Leiden, The Netherlands; (J.A.A.C.H.); (G.J.G.)
| | - Geert Jan Groeneveld
- Centre for Human Drug Research, Zernikedreef 8, 2333 CL Leiden, The Netherlands; (J.A.A.C.H.); (G.J.G.)
- Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
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15
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Ahmed H, Haider A, Ametamey SM. N-Methyl-D-Aspartate (NMDA) receptor modulators: a patent review (2015-present). Expert Opin Ther Pat 2020; 30:743-767. [PMID: 32926646 DOI: 10.1080/13543776.2020.1811234] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
INTRODUCTION - The NMDA receptor is implicated in various diseases including neurodegenerative, neurodevelopmental and mood disorders. However, only a limited number of clinically approved NMDA receptor modulators are available. Today, apparent NMDA receptor drug development strategies entail 1) exploring the unknown chemical space to identify novel scaffolds; 2) using the clinically available NMDA receptor modulators to expand the therapeutic indication space; 3) and to trace physiological functions of the NMDA receptor. AREAS COVERED - The current review reflects on the functional and pharmacological facets of NMDA receptors and the current clinical status quo of NMDA receptor modulators. Patent literature covering 2015 till April 2020 is discussed with emphasis on new indications. EXPERT OPINION - Supporting evidence shows that subtype-selective NMDA receptor antagonists show an improved safety profile compared to broad-spectrum channel blockers. Although GluN2B-selective antagonists are by far the most extensively investigated subtype-selective modulators, they have shown only modest clinical efficacy so far. To overcome the limitations that have hampered the clinical development of previous subtype-selective NMDA receptor antagonists, future studies with improved animal models that better reflect human NMDA receptor pathophysiology are warranted. The increased availability of subtype-selective probes will allow target engagement studies and proper dose finding in future clinical trials.
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Affiliation(s)
- Hazem Ahmed
- Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, ETH Zurich , Zurich, Switzerland
| | - Ahmed Haider
- Department of Nuclear Medicine, University Hospital Zurich , Zurich, Switzerland.,Center for Molecular Cardiology, University of Zurich , Schlieren, Switzerland
| | - Simon M Ametamey
- Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, ETH Zurich , Zurich, Switzerland
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16
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Deen M, Hougaard A, Hansen HD, Schain M, Dyssegaard A, Knudsen GM, Ashina M. Association Between Sumatriptan Treatment During a Migraine Attack and Central 5-HT1B Receptor Binding. JAMA Neurol 2020; 76:834-840. [PMID: 31135819 DOI: 10.1001/jamaneurol.2019.0755] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Importance Triptans, the most efficient acute treatment for migraine attacks, are 5-HT1B/1D receptor agonists, but their precise mechanism of action is not completely understood. The extent to which triptans enter the central nervous system and bind to 5-HT1B receptors in the brain is unknown. Objectives To determine the occupancy of sumatriptan to central 5-HT1B receptors, and to investigate changes in brain serotonin levels during migraine attacks. Design, Setting, and Participants This study of 8 patients in Denmark used a within-participant design and was conducted from April 20, 2015, to December 5, 2016. Participants were otherwise healthy patients with untreated episodic migraine without aura, aged between 18 and 65 years, and recruited from the general community. Data analysis was performed from January 2017 to April 2018. Interventions All participants underwent positron emission tomographic scans after injection of [11C]AZ10419369, a specific 5-HT1B receptor radiotracer. All participants were scanned 3 times: (1) during an experimentally induced migraine attack, (2) after a subcutaneous injection of 6-mg subcutaneous sumatriptan, and (3) on a migraine attack-free day. Scans 1 and 2 were conducted on the same study day. Each scan lasted for 90 minutes. Main Outcome and Measure The primary outcome was the nondisplaceable binding potential of [11C]AZ10419369 across 7 brain regions involved in pain modulation. The binding potential reflects receptor density, and changes in binding potential reflects displacement of the radiotracer. The occupancy of sumatriptan was estimated from the 2 scans before and after sumatriptan administration. Results Eight patients with migraine were included in the study; of these participants, 7 (87%) were women. The mean (SD) age of participants on study day 1 was 29.5 (9.2) years and on study day 2 was 30.0 (8.9) years. Sumatriptan was associated with statistically significantly reduced 5-HT1B receptor binding across pain-modulating regions (mean [SD] binding potential, 1.20 [0.20] vs 1.02 [0.22]; P = .001), corresponding to a mean (SD) drug occupancy rate of 16.0% (5.3%). Furthermore, during migraine attacks, as compared with outside of attacks, 5-HT1B receptor binding was statistically significantly associated with reduced in pain-modulating regions (mean [SD] binding potential, 1.36 [0.22] vs 1.20 [0.20]; P = .02). Conclusions and Relevance Treatment with sumatriptan during migraine attacks appeared to be associated with a decrease in 5-HT1B receptor binding, a finding that is most likely associated with the binding of sumatriptan to central 5-HT1B receptors, but the contribution of ongoing cerebral serotonin release to the lower binding cannot be excluded; the migraine attack-associated decrease in binding could indicate that migraine attacks are associated with increases in endogenous serotonin.
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Affiliation(s)
- Marie Deen
- Danish Headache Center, Department of Neurology, Rigshospitalet, Glostrup, Denmark.,Neurobiology Research Unit and NeuroPharm, Department of Neurology, Rigshospitalet, Copenhagen, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Anders Hougaard
- Danish Headache Center, Department of Neurology, Rigshospitalet, Glostrup, Denmark
| | - Hanne Demant Hansen
- Neurobiology Research Unit and NeuroPharm, Department of Neurology, Rigshospitalet, Copenhagen, Denmark
| | - Martin Schain
- Neurobiology Research Unit and NeuroPharm, Department of Neurology, Rigshospitalet, Copenhagen, Denmark
| | - Agnete Dyssegaard
- Neurobiology Research Unit and NeuroPharm, Department of Neurology, Rigshospitalet, Copenhagen, Denmark
| | - Gitte Moos Knudsen
- Neurobiology Research Unit and NeuroPharm, Department of Neurology, Rigshospitalet, Copenhagen, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Messoud Ashina
- Danish Headache Center, Department of Neurology, Rigshospitalet, Glostrup, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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17
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Rischka L, Gryglewski G, Berroterán-Infante N, Rausch I, James GM, Klöbl M, Sigurdardottir H, Hartenbach M, Hahn A, Wadsak W, Mitterhauser M, Beyer T, Kasper S, Prayer D, Hacker M, Lanzenberger R. Attenuation Correction Approaches for Serotonin Transporter Quantification With PET/MRI. Front Physiol 2019; 10:1422. [PMID: 31824335 PMCID: PMC6883225 DOI: 10.3389/fphys.2019.01422] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 11/04/2019] [Indexed: 12/26/2022] Open
Abstract
Background Several MR-based attenuation correction (AC) approaches were developed to conquer the challenging AC in hybrid PET/MR imaging. These AC methods are commonly evaluated on standardized uptake values or tissue concentration. However, in neurotransmitter system studies absolute quantification is more favorable due to its accuracy. Therefore, our aim was to investigate the accuracy of segmentation- and atlas-based MR AC approaches on serotonin transporter (SERT) distribution volumes and occupancy after a drug challenge. Methods 18 healthy subjects (7 male) underwent two [11C]DASB PET/MRI measurements in a double-blinded, placebo controlled, cross-over design. After 70 min the selective serotonin reuptake inhibitor (SSRI) citalopram or a placebo was infused. The parameters total and specific volume of distribution (VT, VS = BPP) and occupancy were quantified. All subjects underwent a low-dose CT scan as reference AC method. Besides the standard AC approaches DIXON and UTE, a T1-weighted structural image was recorded to estimate a pseudo-CT based on an MR/CT database (pseudoCT). Another evaluated AC approach superimposed a bone model on AC DIXON. Lastly, an approach optimizing the segmentation of UTE images was analyzed (RESOLUTE). PET emission data were reconstructed with all 6 AC methods. The accuracy of the AC approaches was evaluated on a region of interest-basis for the parameters VT, BPP, and occupancy with respect to the results of AC CT. Results Variations for VT and BPP were found with all AC methods with bias ranging from -15 to 17%. The smallest relative errors for all regions were found with AC pseudoCT (<|5%|). Although the bias between BPP SSRI and BPP placebo varied markedly with AC DIXON (<|12%|) and AC UTE (<|9%|), a high correlation to AC CT was obtained (r 2∼1). The relative difference of the occupancy for all tested AC methods was small for SERT high binding regions (<|4%|). Conclusion The high correlation might offer a rescaling from the biased parameters VT and BPP to the true values. Overall, the pseudoCT approach yielded smallest errors and the best agreement with AC CT. For SERT occupancy, all AC methods showed little bias in high binding regions, indicating that errors may cancel out in longitudinal assessments.
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Affiliation(s)
- Lucas Rischka
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
| | - Gregor Gryglewski
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
| | - Neydher Berroterán-Infante
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Ivo Rausch
- QIMP Group, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Gregory Miles James
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
| | - Manfred Klöbl
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
| | - Helen Sigurdardottir
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
| | - Markus Hartenbach
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Andreas Hahn
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
| | - Wolfgang Wadsak
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria.,CBmed, Graz, Austria
| | - Markus Mitterhauser
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria.,Ludwig Boltzmann Institute Applied Diagnostics, Vienna, Austria
| | - Thomas Beyer
- QIMP Group, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Siegfried Kasper
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
| | - Daniela Prayer
- Division of Neuroradiology and Musculoskeletal Radiology, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Marcus Hacker
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Rupert Lanzenberger
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
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18
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Ahmed H, Haider A, Varisco J, Stanković M, Wallimann R, Gruber S, Iten I, Häne S, Müller Herde A, Keller C, Schibli R, Schepmann D, Mu L, Wünsch B, Ametamey SM. Structure–Affinity Relationships of 2,3,4,5-Tetrahydro-1H-3-benzazepine and 6,7,8,9-Tetrahydro-5H-benzo[7]annulen-7-amine Analogues and the Discovery of a Radiofluorinated 2,3,4,5-Tetrahydro-1H-3-benzazepine Congener for Imaging GluN2B Subunit-Containing N-Methyl-d-aspartate Receptors. J Med Chem 2019; 62:9450-9470. [DOI: 10.1021/acs.jmedchem.9b00812] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Hazem Ahmed
- Institute of Pharmaceutical Sciences, ETH Zurich, Vladimir-Prelog-Weg 4, 8093 Zurich, Switzerland
| | - Ahmed Haider
- Institute of Pharmaceutical Sciences, ETH Zurich, Vladimir-Prelog-Weg 4, 8093 Zurich, Switzerland
| | - Jasmine Varisco
- Institute of Pharmaceutical Sciences, ETH Zurich, Vladimir-Prelog-Weg 4, 8093 Zurich, Switzerland
| | - Maja Stanković
- Institute of Pharmaceutical Sciences, ETH Zurich, Vladimir-Prelog-Weg 4, 8093 Zurich, Switzerland
| | - Rahel Wallimann
- Institute of Pharmaceutical Sciences, ETH Zurich, Vladimir-Prelog-Weg 4, 8093 Zurich, Switzerland
| | - Stefan Gruber
- Institute of Pharmaceutical Sciences, ETH Zurich, Vladimir-Prelog-Weg 4, 8093 Zurich, Switzerland
| | - Irina Iten
- Institute of Pharmaceutical Sciences, ETH Zurich, Vladimir-Prelog-Weg 4, 8093 Zurich, Switzerland
| | - Surya Häne
- Institute of Pharmaceutical Sciences, ETH Zurich, Vladimir-Prelog-Weg 4, 8093 Zurich, Switzerland
| | - Adrienne Müller Herde
- Institute of Pharmaceutical Sciences, ETH Zurich, Vladimir-Prelog-Weg 4, 8093 Zurich, Switzerland
| | - Claudia Keller
- Institute of Pharmaceutical Sciences, ETH Zurich, Vladimir-Prelog-Weg 4, 8093 Zurich, Switzerland
| | - Roger Schibli
- Institute of Pharmaceutical Sciences, ETH Zurich, Vladimir-Prelog-Weg 4, 8093 Zurich, Switzerland
- Department of Nuclear Medicine, University Hospital Zurich, 8091 Zurich, Switzerland
| | - Dirk Schepmann
- Institute of Pharmaceutical and Medicinal Chemistry, University of Münster, Corrensstr. 48, 48149 Münster, Germany
| | - Linjing Mu
- Institute of Pharmaceutical Sciences, ETH Zurich, Vladimir-Prelog-Weg 4, 8093 Zurich, Switzerland
- Department of Nuclear Medicine, University Hospital Zurich, 8091 Zurich, Switzerland
| | - Bernhard Wünsch
- Institute of Pharmaceutical and Medicinal Chemistry, University of Münster, Corrensstr. 48, 48149 Münster, Germany
| | - Simon M. Ametamey
- Institute of Pharmaceutical Sciences, ETH Zurich, Vladimir-Prelog-Weg 4, 8093 Zurich, Switzerland
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19
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Xu Y, Miao X, Ravenstijn P, Hijzen A, Schmidt ME, Nandy P, Zhou H. Translational Model-Informed Dose Selection for a Human Positron Emission Tomography Imaging Study of JNJ-54175446, a P2X7 Receptor Antagonist. Clin Transl Sci 2019; 13:309-317. [PMID: 31642608 PMCID: PMC7070800 DOI: 10.1111/cts.12711] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 08/30/2019] [Indexed: 12/02/2022] Open
Abstract
Positron emission tomography (PET) provides useful information in target engagement or receptor occupancy in the brain for central nervous system (CNS) drug development, however, dose selection for human PET studies is challenging and largely empirical. Here, we describe a translational pharmacokinetic/pharmacodynamic (PK/PD) modeling work to inform dose selection for a human PET study of JNJ‐54175446, a CNS‐penetrating P2X7 receptor antagonist. Models were developed using data on monkey brain occupancy and plasma drug exposures from a monkey PET study and early human clinical studies that provided data on drug exposures and human ex vivo‐stimulated peripheral interleukin (IL)‐1β release. The observed plasma PK of JNJ‐54175446 in human was adequately described by a one‐compartment model with parallel zero‐order and first‐order absorption and first‐order elimination. An exposure‐occupancy model was extrapolated from monkey to human assuming a similar unbound potency (all other model parameters remained unchanged). This model was then used to simulate human brain occupancy to guide human PET study dose selection, together with the human population PK model. The corroboration of model predicted occupancy by the observed occupancy data from the human PET study supports the use of a monkey as a predictive model for human PET target engagement. Potency estimate for brain occupancy was generally comparable to that for the suppression of the provoked peripheral IL‐1β release ex vivo, indicating that blood IL‐1β release may be used as a surrogate of central occupancy for JNJ‐54175446. Translational PK/PD modeling approach could be used for selecting optimal doses for human PET and other clinical studies.
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Affiliation(s)
- Yan Xu
- Clinical Pharmacology and Pharmacometrics, Janssen Research & Development, LLC, Springhouse, Pennsylvania, USA
| | - Xin Miao
- Clinical Pharmacology and Pharmacometrics, Janssen Research & Development, LLC, Springhouse, Pennsylvania, USA
| | - Paulien Ravenstijn
- Clinical Pharmacology and Pharmacometrics, Janssen Research & Development, LLC, Beerse, Belgium
| | - Anja Hijzen
- Neuroscience Experimental Medicine, Janssen Research & Development, LLC, Beerse, Belgium
| | - Mark E Schmidt
- Neuroscience Experimental Medicine, Janssen Research & Development, LLC, Beerse, Belgium
| | - Partha Nandy
- Clinical Pharmacology and Pharmacometrics, Janssen Research & Development, LLC, Titusville, New Jersey, USA
| | - Honghui Zhou
- Clinical Pharmacology and Pharmacometrics, Janssen Research & Development, LLC, Springhouse, Pennsylvania, USA
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20
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Sarnyai Z, Nagy K, Patay G, Molnár M, Rosenqvist G, Tóth M, Takano A, Gulyás B, Major P, Halldin C, Varrone A. Performance Evaluation of a High-Resolution Nonhuman Primate PET/CT System. J Nucl Med 2019; 60:1818-1824. [PMID: 31302634 DOI: 10.2967/jnumed.117.206243] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 05/07/2019] [Indexed: 11/16/2022] Open
Abstract
The LFER 150 PET/CT device (large-field-of-view extreme-resolution portable research imager) is a system for nonhuman primate (NHP) imaging. The objective of this study was to evaluate the performance of the system using the National Electrical Manufacturers Association NU 4-2008 standard protocol. As a preliminary in vivo evaluation of the system, a PET measurement in an NHP was also performed. Methods: Resolution, sensitivity, image quality, and noise-equivalent count rate (NECR) were measured. NECR measurement was performed with a ratlike phantom and a monkeylike phantom. A Derenzo phantom experiment was performed to test the resolution using 3-dimensional ordered-subset expectation maximization reconstruction. One cynomolgus monkey (4.5 kg, intravenous ketamine/xylazine anesthesia) was examined with the dopamine transporter radioligand 18F-FE-PE2I (94 MBq) to evaluate the in vivo performance of the system. List-mode PET data acquired for 93 min were reconstructed into 38 frames with the Tera-Tomo 3-dimensional engine. Binding potential for caudate nucleus, putamen, and substantia nigra was evaluated using the simplified reference tissue model. Results: Radial full-width half-maximum resolution using Fourier rebinning and a 2-dimensional filtered backprojection algorithm was less than 2.2 mm and less than 3.2 mm in the central 60-mm-diameter and 140-mm-diameter regions, respectively. Maximum sensitivity in the 400- to 600-keV and 250- to 750-keV energy windows was 30.03 cps/kBq (3.3%) and 49.11 cps/kBq (5.4%), respectively. The uniformity in the image-quality phantom was 3.3%, and the spillover ratio for air and water was 0.1. The peak of the NECR curve was 430 kcps (at 115 MBq) with the ratlike phantom and 78 kcps (at 139 MBq) with the monkeylike phantom. Rods of the Derenzo phantom with 1-mm diameter could be distinguished by eye. In the NHP experiment, binding potentials in the caudate, putamen, and substantia nigra (4.9, 4.9, and 1, respectively) were similar to those previously reported using the same radioligand and a high-resolution research tomograph. Conclusion: The results obtained from phantom experiments and 1 representative PET measurement in an NHP confirm that the LFER 150 is a high-resolution PET/CT system with suitable performance for brain imaging in NHPs.
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Affiliation(s)
- Zsolt Sarnyai
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden
| | | | | | | | - Göran Rosenqvist
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden
| | - Miklós Tóth
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden
| | - Akihiro Takano
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden
| | - Balázs Gulyás
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden.,Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | | | - Christer Halldin
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden.,Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Andrea Varrone
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden
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21
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Arakawa R, Farde L, Matsumoto J, Kanegawa N, Yakushev I, Yang KC, Takano A. Potential Effect of Prolonged Sevoflurane Anesthesia on the Kinetics of [ 11C]Raclopride in Non-human Primates. Mol Imaging Biol 2019; 20:183-187. [PMID: 28916921 PMCID: PMC5862918 DOI: 10.1007/s11307-017-1120-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Purpose Positron emission tomography (PET) in non-human primates (NHP) is commonly performed under anesthesia, with sevoflurane being a widely used inhaled anesthetic. PET measurement in NHP can be repeated, and a difference in radioligand kinetics has previously been observed between the first and second PET measurement on the same day using sevoflurane anesthesia. In this study, we evaluated the effect of prolonged sevoflurane anesthesia on kinetics and binding potential (BPND) of [11C]raclopride in NHP. Procedures Three cynomolgus monkeys underwent two to three PET measurements with [11C]raclopride under continuous sevoflurane anesthesia on the same day. The concentration of sevoflurane was adjusted according to the general conditions and safety parameters of the NHP. Time to peak (TTP) radioactivity in the striatum was estimated from time-activity curves (TACs). The BPND in the striatum was calculated by the simplified reference tissue model using the cerebellum as reference region. Results In each NHP, the TTP became shorter in the later PET measurements than in the first one. Across all measurements (n = 8), concentration of sevoflurane correlated with TTP (Spearman’s ρ = − 0.79, p = 0.03), but not with BPND (ρ = − 0.25, p = 0.55). Conclusions These data suggest that sevoflurane affects the shape of TACs but has no evident effect on BPND in consecutive PET measurements.
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Affiliation(s)
- Ryosuke Arakawa
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden.
| | - Lars Farde
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden.,Personalized Health Care and Biomarkers, AstraZeneca PET Science Center, Karolinska Institutet, Stockholm, Sweden
| | - Junya Matsumoto
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden.,Department of Neuropsychiatry, School of Medicine, Fukushima Medical University, Fukushima, Japan
| | - Naoki Kanegawa
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden
| | - Igor Yakushev
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden.,Department of Nuclear Medicine and TUM Neuroimaging Center (TUM-NIC), Technische Universität München, Munich, Germany
| | - Kai-Chun Yang
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden
| | - Akihiro Takano
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden
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22
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Abstract
The process of discovering and developing a new pharmaceutical is a long, difficult, and risky process that requires numerous resources. Molecular imaging techniques such as PET have recently become a useful tool for making decisions along a drug candidate's development timeline. PET is a translational, noninvasive imaging technique that provides quantitative information about a potential drug candidate and its target at the molecular level. Using this technique provides decisional information to ensure that the right drug candidate is being chosen, for the right target, at the right dose within the right patient population. This review will focus on small molecule PET tracers and how they are used within the drug discovery process. PET provides key information about a drug candidate's pharmacokinetic and pharmacodynamic properties in both preclinical and clinical studies. PET is being used in all phases of the drug discovery and development process, and the goal of these studies are to accelerate the process in which drugs are developed.
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Affiliation(s)
- David J Donnelly
- Bristol-Myers Squibb Pharmaceutical Research and Development, Princeton, NJ.
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23
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Zinnhardt B, Wiesmann M, Honold L, Barca C, Schäfers M, Kiliaan AJ, Jacobs AH. In vivo imaging biomarkers of neuroinflammation in the development and assessment of stroke therapies - towards clinical translation. Theranostics 2018; 8:2603-2620. [PMID: 29774062 PMCID: PMC5956996 DOI: 10.7150/thno.24128] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 01/31/2018] [Indexed: 01/01/2023] Open
Abstract
Modulation of the inflammatory microenvironment after stroke opens a new avenue for the development of novel neurorestorative therapies in stroke. Understanding the spatio-temporal profile of (neuro-)inflammatory imaging biomarkers in detail thereby represents a crucial factor in the development and application of immunomodulatory therapies. The early integration of quantitative molecular imaging biomarkers in stroke drug development may provide key information about (i) early diagnosis and follow-up, (ii) spatio-temporal drug-target engagement (pharmacodynamic biomarker), (iii) differentiation of responders and non-responders in the patient cohort (inclusion/exclusion criteria; predictive biomarkers), and (iv) the mechanism of action. The use of targeted imaging biomarkers for may thus allow clinicians to decipher the profile of patient-specific inflammatory activity and the development of patient-tailored strategies for immunomodulatory and neuro-restorative therapies in stroke. Here, we highlight the recent developments in preclinical and clinical molecular imaging biomarkers of neuroinflammation (endothelial markers, microglia, MMPs, cell labeling, future developments) in stroke and outline how imaging biomarkers can be used in overcoming current translational roadblocks and attrition in order to advance new immunomodulatory compounds within the clinical pipeline.
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Affiliation(s)
- Bastian Zinnhardt
- European Institute for Molecular Imaging (EIMI), Westfälische Wilhelms University Münster, Münster, Germany
- EU 7 th FP Programme “Imaging Inflammation in Neurodegenerative Diseases (INMiND)”
- Cells in Motion (CiM) Cluster of Excellence, University of Münster, Münster, Germany
- PET Imaging in Drug Design and Development (PET3D)
- Department of Nuclear Medicine, Universitätsklinikum Münster, Münster, Germany
| | - Maximilian Wiesmann
- Department of Anatomy, Radboud university medical center, Donders Institute for Brain, Cognition & Behaviour, Nijmegen, The Netherlands
| | - Lisa Honold
- European Institute for Molecular Imaging (EIMI), Westfälische Wilhelms University Münster, Münster, Germany
| | - Cristina Barca
- European Institute for Molecular Imaging (EIMI), Westfälische Wilhelms University Münster, Münster, Germany
- PET Imaging in Drug Design and Development (PET3D)
| | - Michael Schäfers
- European Institute for Molecular Imaging (EIMI), Westfälische Wilhelms University Münster, Münster, Germany
- Cells in Motion (CiM) Cluster of Excellence, University of Münster, Münster, Germany
- Department of Nuclear Medicine, Universitätsklinikum Münster, Münster, Germany
| | - Amanda J Kiliaan
- Department of Anatomy, Radboud university medical center, Donders Institute for Brain, Cognition & Behaviour, Nijmegen, The Netherlands
| | - Andreas H Jacobs
- European Institute for Molecular Imaging (EIMI), Westfälische Wilhelms University Münster, Münster, Germany
- EU 7 th FP Programme “Imaging Inflammation in Neurodegenerative Diseases (INMiND)”
- Cells in Motion (CiM) Cluster of Excellence, University of Münster, Münster, Germany
- PET Imaging in Drug Design and Development (PET3D)
- Department of Geriatrics, Johanniter Hospital, Evangelische Kliniken, Bonn, Germany
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24
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Murphy PS, Patel N, McCarthy TJ. Has molecular imaging delivered to drug development? PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2017; 375:rsta.2017.0112. [PMID: 29038381 PMCID: PMC5647269 DOI: 10.1098/rsta.2017.0112] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/31/2017] [Indexed: 06/07/2023]
Abstract
Pharmaceutical research and development requires a systematic interrogation of a candidate molecule through clinical studies. To ensure resources are spent on only the most promising molecules, early clinical studies must understand fundamental attributes of the drug candidate, including exposure at the target site, target binding and pharmacological response in disease. Molecular imaging has the potential to quantitatively characterize these properties in small, efficient clinical studies. Specific benefits of molecular imaging in this setting (compared to blood and tissue sampling) include non-invasiveness and the ability to survey the whole body temporally. These methods have been adopted primarily for neuroscience drug development, catalysed by the inability to access the brain compartment by other means. If we believe molecular imaging is a technology platform able to underpin clinical drug development, why is it not adopted further to enable earlier decisions? This article considers current drug development needs, progress towards integration of molecular imaging into studies, current impediments and proposed models to broaden use and increase impact.This article is part of the themed issue 'Challenges for chemistry in molecular imaging'.
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Affiliation(s)
| | - Neel Patel
- GlaxoSmithKline, Gunnels Wood Road, Stevenage SG1 2NY, UK
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