Advances in CNS PET: the state-of-the-art for new imaging targets for pathophysiology and drug development
- PMID: 31541283
- PMCID: PMC6974496
- DOI: 10.1007/s00259-019-04488-0
Advances in CNS PET: the state-of-the-art for new imaging targets for pathophysiology and drug development
Abstract
Purpose: A limit on developing new treatments for a number of central nervous system (CNS) disorders has been the inadequate understanding of the in vivo pathophysiology underlying neurological and psychiatric disorders and the lack of in vivo tools to determine brain penetrance, target engagement, and relevant molecular activity of novel drugs. Molecular neuroimaging provides the tools to address this. This article aims to provide a state-of-the-art review of new PET tracers for CNS targets, focusing on developments in the last 5 years for targets recently available for in-human imaging.
Methods: We provide an overview of the criteria used to evaluate PET tracers. We then used the National Institute of Mental Health Research Priorities list to identify the key CNS targets. We conducted a PubMed search (search period 1st of January 2013 to 31st of December 2018), which yielded 40 new PET tracers across 16 CNS targets which met our selectivity criteria. For each tracer, we summarised the evidence of its properties and potential for use in studies of CNS pathophysiology and drug evaluation, including its target selectivity and affinity, inter and intra-subject variability, and pharmacokinetic parameters. We also consider its potential limitations and missing characterisation data, but not specific applications in drug development. Where multiple tracers were present for a target, we provide a comparison of their properties.
Results and conclusions: Our review shows that multiple new tracers have been developed for proteinopathy targets, particularly tau, as well as the purinoceptor P2X7, phosphodiesterase enzyme PDE10A, and synaptic vesicle glycoprotein 2A (SV2A), amongst others. Some of the most promising of these include 18F-MK-6240 for tau imaging, 11C-UCB-J for imaging SV2A, 11C-CURB and 11C-MK-3168 for characterisation of fatty acid amide hydrolase, 18F-FIMX for metabotropic glutamate receptor 1, and 18F-MNI-444 for imaging adenosine 2A. Our review also identifies recurrent issues within the field. Many of the tracers discussed lack in vivo blocking data, reducing confidence in selectivity. Additionally, late-stage identification of substantial off-target sites for multiple tracers highlights incomplete pre-clinical characterisation prior to translation, as well as human disease state studies carried out without confirmation of test-retest reproducibility.
Keywords: Brain; CNS; First-in-human; PET.
Conflict of interest statement
Stuart McCluskey, Christophe Plisson Eugenii Rabiner are full-time employees of Invicro LLC. Oliver Howes has received investigator-initiated research funding from and/or participated in advisory/speaker meetings organised by Angellini, Astra-Zeneca, Autifony, Biogen, BMS, Eli Lilly, Heptares, Jansenn, Lundbeck, Lyden-Delta, Otsuka, Servier, Sunovion, Rand, Recordati, and Roche.
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References
-
- Lopez AD, Murray CCJL. The global burden of disease, 1990–2020. Nat Med. 1998;4:1241–1243. - PubMed
-
- Vigo D, Thornicroft G, Atun R. Estimating the true global burden of mental illness. Lancet Psychiatry. 2016;3:171–178. - PubMed
-
- Pangalos MN, Schechter LE, Hurko O. Drug development for CNS disorders: strategies for balancing risk and reducing attrition. Nat Rev Drug Discov. 2007;6:521–532. - PubMed
-
- Kim E, Howes OD, Turkheimer FE, Kim B-H, Jeong JM, Kim JW, et al. The relationship between antipsychotic D2 occupancy and change in frontal metabolism and working memory. Psychopharmacology. 2013;227:221–229. - PubMed
-
- Long NJ, Wong WT. The chemistry of molecular imaging. 2015.
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