Automation; Fluorine-18; Good manufacturing practice; Positron emission tomography; [18F]Flumazenil; Radiology, Nuclear Medicine and Imaging; Pharmacology
Abstract :
[en] ("[en] BACKGROUND: Flumazenil (FMZ) is a functionally silent imidazobenzodiazepine which binds to the benzodiazepine binding site of approximately 75% of the brain γ-aminobutyric acid-A receptors (GABAARs). Positron Emission Tomography (PET) imaging of the GABAARs with [11C]FMZ has been used to evidence alterations in neuronal density, to assess target engagement of novel pharmacological agents, and to study disorders such as epilepsy and Huntington's disease. Despite the potential of FMZ PET imaging the short half-life (t1/2) of carbon-11 (20 min) has limited the more widespread clinical use of [11C]FMZ. The fluorine-18 (18F) isotopologue with a longer t1/2 (110 min) is ideally suited to address this drawback. However, the majority of current radiochemical methods for the synthesis of [18F]FMZ are non-trivial and low yielding. We report a robust, automated protocol that is good manufacturing practice (GMP) compatible, and yields multi-patient doses of [18F]FMZ.
RESULTS: The fully automated synthesis was developed on the Trasis AllinOne (AIO) platform using a single-use cassette. [18F]FMZ was synthesized in a one-step procedure from [18F]fluoride, via a copper-mediated 18F-fluorination of a boronate ester precursor. Purification was performed by semi-preparative radio-HPLC and the collected fraction formulated directly into the final product vial. The overall process from start of synthesis to delivery of product is approximately 55 min. Starting with an initial activity of 23.6 ± 5.8 GBq (n = 3) activity yields of [18F]FMZ were 8.0 ± 1 GBq (n = 3). The synthesis was successfully reproduced at two independent sites, where the product passed quality control release criteria in line with the European Pharmacopoeia standards and ICH Q3D(R1) guidelines to be suitable for human use.
CONCLUSION: Reported is a fully automated cassette-based synthesis of [18F]FMZ that is Good Manufacturing Practice (GMP) compatible and produces multi-patient doses of [18F]FMZ.","[en] ","")
Disciplines :
Chemistry Radiology, nuclear medicine & imaging
Author, co-author :
Gendron, Thibault ; Université de Liège - ULiège > Département de chimie (sciences) > Chimie organique-nucléaire ; Trasis, Rue Gilles Magnée, 90, 4430, Ans, Belgium
Destro, Gianluca; Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, UK
Straathof, Natan J W; Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, UK
Sap, Jeroen B I; Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, UK
Guibbal, Florian; Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, UK
Vriamont, Charles; Trasis, Rue Gilles Magnée, 90, 4430, Ans, Belgium
Caygill, Claire; Medicines Discovery Institute, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, UK
Atack, John R; Medicines Discovery Institute, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, UK
Watkins, Andrew J; Wales Research and Diagnostic PET Imaging Centre, Cardiff University, University Hospital of Wales, Heath Park, Cardiff, CF14 4XN, UK
Marshall, Christopher; Wales Research and Diagnostic PET Imaging Centre, Cardiff University, University Hospital of Wales, Heath Park, Cardiff, CF14 4XN, UK
Hueting, Rebekka; Wales Research and Diagnostic PET Imaging Centre, Cardiff University, University Hospital of Wales, Heath Park, Cardiff, CF14 4XN, UK
Warnier, Corentin ; Université de Liège - ULiège > Unités de recherche interfacultaires > GIGA-CRC In vivo Imaging (Centre de Recherche du Cyclotron) ; Trasis, Rue Gilles Magnée, 90, 4430, Ans, Belgium
Gouverneur, Véronique; Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, UK. veronique.gouverneur@chem.ox.ac.uk
Tredwell, Matthew ; Wales Research and Diagnostic PET Imaging Centre, Cardiff University, University Hospital of Wales, Heath Park, Cardiff, CF14 4XN, UK. tredwellm@cardiff.ac.uk ; School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, UK. tredwellm@cardiff.ac.uk
MRC - Medical Research Council [GB] EPSRC - Engineering and Physical Sciences Research Council [GB]
Funding number :
EP/R511742/1
Funding text :
This research was supported by MRC Confidence in Concept Scheme (MC_PC_19033) funding (MT, CM) and an EPSRC Impact Accelerator Award (EP/R511742/1) (VG).
Atack JR, Wafford KA, Tye SJ, et al. TPA023 [7-(1,1-dimethylethyl)-6-(2-ethyl-2H-1,2,4-triazol-3-(2-fluorophenyl)-1,2,4-triazolo[4,3-b]pyridazine], an agonist selective for α2- and α3-containing GABAA receptors, is a non-sedating anxiolytic in rodents and primates. J Pharmacol Exp Ther. 2006;316:410–22. DOI: 10.1124/jpet.105.089920
Atack JR, Wong DF, Fryer TD, et al. Benzodiazepine binding site occupancy by the novel GABAA receptor subtype-selective drug 7-(1,1-dimethylethyl)-6-(2-ethyl-2H-1,2,4-triazol-3-ylmethoxy)-3-(2-fluorophenyl)-1,2,4-triazolo[4,3-b]pyridazine (TPA023) in rats, primates, and humans. J Pharmacol Exp Ther. 2010;332:17–25. DOI: 10.1124/jpet.109.157909
Brooks AF, Topczewski JJ, Ichiishi N, Sanford MS, Scott PJH. Late-stage [18F]fluorination: new solutions to old problems. Chem Sci. 2014;5:4545–53. DOI: 10.1039/C4SC02099E
Cardinale J, Martin R, Remde Y, et al. Procedures for the GMP-compliant production and quality control of [18F]PSMA-1007: a next generation radiofluorinated tracer for the detection of prostate cancer. Pharmaceuticals. 2017;10:77. DOI: 10.3390/ph10040077
Deng X, Rong J, Wang L, et al. Chemistry for positron emission tomography: recent advances in 11C-, 18F-, 13N-, and 15O-labeling reactions. Angew Chem Int Ed. 2019;58:2580–605. DOI: 10.1002/anie.201805501
Eng W, Atack JR, Sanabria S, et al, Occupancy of human brain GABAA receptors by the α5 subtype-selective benzodiazepine site inverse agonist α5IA as measured using [11C]flumazenil PET imaging. Neuropharmacology. 2010;59635–639
Flumazenil (N-[11C]methyl injection 01/2008:1917, Radiopharmaceutical preparations. In European Pharmacopeia. 9.0; 1137–1139.
Flumazenil, European Pharmacopeia, 10.7; 2655
Gu Z-Q, Wong G, Dominguez S, et al. Synthesis and evaluation of imidazo[1,5-a][1,4]benzodiazepine esters with high affinities and selectivities at “diazepam-insensitive” benzodiazepine receptors. J Med Chem. 1993;36:1001–6. DOI: 10.1021/jm00060a007
Guibbal F, Isenegger PG, Wilson TC, et al. Manual and automated Cu-mediated radiosynthesis of the PARP inhibitor [18F]olaparib. Nat Protoc. 2020;15:1525–41. DOI: 10.1038/s41596-020-0295-7
Heiss W-D, Kracht L, Grond M, et al. Early [11C]flumazenil/H2O positron emission tomography predicts irreversible ischemic cortical damage in stroke patients receiving acute thrombolytic therapy. Stroke. 2000;31:366–9. DOI: 10.1161/01.STR.31.2.366
Holthoff VA, Koeppe RA, Frey KA, et al. Positron emission tomography measures of benzodiazepine receptors in Huntington’s disease. Ann Neurol. 1993;34:76–81. DOI: 10.1002/ana.410340114
Koepp MJ, Labbé C, Richardson MP. et aal, Regional hippocampal [11C]flumazenil PET in temporal lobe epilepsy with unilateral and bilateral hippocampal sclerosis. Brain. 1997;120:1865–76. DOI: 10.1093/brain/120.10.1865
Koziorowski J, Behe M, Decristoforo C, et al. Position paper on requirements for toxicological studies in the specific case of radiopharmaceuticals. EJNMMI Radiopharm Chem. 2017;1:1. DOI: 10.1186/s41181-016-0004-6
Kumar P, Nagaraj C, Joshi R, et al. Radiosynthesis of [18F]flumazenil for imaging benzodiazepine receptors and its evaluation in human volunteers using simultaneous PET-MRI. J Radioanal Nucl Chem. 2021;329:581–9. DOI: 10.1007/s10967-021-07859-w
Malizia AL, Cunningham VJ, Bell CJ, Liddle PF, Jones T, Nutt DJ. Decreased brain GABAA-benzodiazepine receptor binding in panic disorder: preliminary results from a quantitative PET study. Arch Gen Psychiatry. 1998;55:715–20. DOI: 10.1001/archpsyc.55.8.715
Massaweh G, Schirrmacher E. la Fougere, et al, Improved work-up procedure for the production of [18F]flumazenil and first results of its use with a high-resolution research tomograph in human stroke. Nucl Med Biol. 2009;36:721–7. DOI: 10.1016/j.nucmedbio.2009.05.008
Moon BS, Kil HS, Park JH, et al. Facile aromatic fluorination of [18F]flumazenil from diaryliodonium salts with evaluation of their stability and selectivity. Org Biomol Chem. 2011;9:8346–55. DOI: 10.1039/c1ob06277h
Moon BS, Park JH, Lee HJ, Lee BC, Kim SE. Routine production of [18F]flumazenil from iodonium tosylate using a sample pretreatment method: a 2.5 year production report. Mol Imaging Biol. 2014;16:619–25. DOI: 10.1007/s11307-014-0738-z
Mossine AV, Brooks AF, Ichiishi N, et al. Development of customized [18F]fluoride elution techniques for the enhancement of copper-mediated late-stage radiofluorination. Sci Rep. 2017;7:1–9. DOI: 10.1038/s41598-017-00110-1
Mossine AV, Brooks AF, Bernard-Gauthier V, et al. Automated synthesis of PET radiotracers by copper mediated-mediated 18F-fluorination of organoborons: importance of the order of addition and competing protodeborylation. J Labelled Comp Radiopharm. 2018;61:228–36. DOI: 10.1002/jlcr.3583
Mossine AV, Tanzey SS, Brooks AF, et al. Synthesis of high-molar-activity [18F]6-fluoro- ʟ-DOPA suitable for human use via Cu-mediated fluorination of a BPin precursor. Nat Protoc. 2020;15:1742–59. DOI: 10.1038/s41596-020-0305-9
Nickolls SA, Gurrell R, van Amerongen G, et al. Pharmacology in translation: the preclinical and early clinical profile of the novel α2/3 functionally selective GABAA receptor positive allosteric modulator PF-06372865. Br J Pharmacol. 2018;175:708–25. DOI: 10.1111/bph.14119
Pappata S, Samson Y, Chavoix C, et al. Regional specific binding of [11C]RO151788 to central type benzodiazepine receptors in human brain: quantitative evaluation by PET. J Cereb Blood Flow Metab. 1988;8:304–13. DOI: 10.1038/jcbfm.1988.65
Ph. Eur. Method 2.4.33 Tetrabutylammonium in Radiopharmaceutical Preparations
Preshlock S, Tredwell M, Gouverneur V. 18F-Labelling of arenes and heteroarenes for applications in positron emission tomography. Chem Rev. 2016a;116:719–66. DOI: 10.1021/acs.chemrev.5b00493
Preshlock S, Calderwood S, Verhoog S, et al. Enhanced copper-mediated 18F-fluorination of aryl boronic esters provides eight radiotracers for PET applications. Chem Commun. 2016b;52:8361–4. DOI: 10.1039/C6CC03295H
Ryvlin P, Bouvard S, Le Bars D, et al. Clinical utility of flumazenil-PET versus [18F]fluorodeoxyglucose-PET and MRI in refractory partial epilepsy: a prospective study in 100 patients. Exp Neurol. 2020;330:113305. DOI: 10.1016/j.expneurol.2020.113305
Ryzhikov NN, Seneca N, Krasikova RN, et al. Preparation of highly specific radioactivity [18F]flumazenil and its evaluation in cynomolgus monkey by positron emission tomography. Nucl Med Biol. 2005;32:109–16. DOI: 10.1016/j.nucmedbio.2004.11.001
Savic I, Persson A, Roland P, Pauli S, Sedvall G, Widén L. In-vivo demonstration of reduced benzodiazepine receptor binding in human epileptic foci. Lancet. 1988;2:863–6. DOI: 10.1016/S0140-6736(88)92468-3
Schirrmacher R, Massaweh G, Kovacevic M, Wängler C, Thiel A. Synthesis of [18F]flumazenil ([18F]FMZ). In: Scott PJH, Hockley BG, editors. Radiochemical syntheses: radiopharmaceuticals for positron emission tomography. New York: Wiley; 2012. p. 111–24. DOI: 10.1002/9781118140345.ch13
Tanzey SS, Mossine AV, Sowa AR, et al. A spot test for determination of residual TBA levels in 18F-radiotracers for human use using Dragendorff reagent. Anal Methods. 2020;12:5004–9. DOI: 10.1039/D0AY01565B
Tredwell M, Preshlock S, Taylor NJ, et al. A general copper-mediated nucleophilic 18F fluorination of arenes. Angew Chem Int Ed. 2014;53:7751–5. DOI: 10.1002/anie.201404436
Vaulina D, Nasirzadeh M, Gomzina N. Automated radiosynthesis and purification of [18F]flumazenil with solid phase extraction. Appl Radiat Isot. 2018;135:110–4. DOI: 10.1016/j.apradiso.2018.01.008
Vivash L, Gregoire M-C. Lau Ew, et al, 18F-Flumazenil: a γ-aminobutyric acid A-specific PET radiotracer for the localization of drug-resistant temporal lobe epilepsy. J Nucl Med. 2013;54:1270–7. DOI: 10.2967/jnumed.112.107359
Wright JS, Kaur T, Preshlock S, et al. Copper-mediated late-stage radiofluorination: five years of impact on preclinical and clinical PET imaging. Clin Transl Imaging. 2020;8:167–206. DOI: 10.1007/s40336-020-00368-y
Zlatopolskiy BD, Zischler J, Krapf P, et al. Copper-mediated aromatic radiofluorination revisited: efficient production of PET tracers on a preparative scale. Chem Eur J. 2015;21:5972–9. DOI: 10.1002/chem.201405586
