A human PET study of [11C]HMS011, a potential radioligand for AMPA receptors

Keisuke Takahata; Yasuyuki Kimura; Chie Seki; Masaki Tokunaga; Masanori Ichise; Kazunori Kawamura; Maiko Ono; Soichiro Kitamura; Manabu Kubota; Sho Moriguchi; Tatsuya Ishii; Yuhei Takado; Fumitoshi Niwa; Hironobu Endo; Tomohisa Nagashima; Yoko Ikoma; Ming-Rong Zhang; Tetsuya Suhara; Makoto Higuchi

doi:10.1186/s13550-017-0313-0

A human PET study of [¹¹C]HMS011, a potential radioligand for AMPA receptors

EJNMMI Res. 2017 Aug 16;7(1):63. doi: 10.1186/s13550-017-0313-0.

Authors

Keisuke Takahata^{1

2}, Yasuyuki Kimura^{3

4}, Chie Seki¹, Masaki Tokunaga¹, Masanori Ichise¹, Kazunori Kawamura⁵, Maiko Ono¹, Soichiro Kitamura¹, Manabu Kubota¹, Sho Moriguchi^{1

6}, Tatsuya Ishii¹, Yuhei Takado¹, Fumitoshi Niwa^{1

7}, Hironobu Endo^{1

8}, Tomohisa Nagashima¹, Yoko Ikoma⁹, Ming-Rong Zhang⁵, Tetsuya Suhara¹, Makoto Higuchi¹

Affiliations

¹ Department of Functional Brain Imaging Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Chiba, Japan.
² Department of Neuropsychiatry, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, 160-8582, Tokyo, Japan.
³ Department of Functional Brain Imaging Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Chiba, Japan. yazkim@ncgg.go.jp.
⁴ Department of Clinical and Experimental Neuroimaging, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, 7-430 Morioka-cho, Obu, 474-8511, Aichi, Japan. yazkim@ncgg.go.jp.
⁵ Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Chiba, Japan.
⁶ Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, M5T 1R8, ON, Canada.
⁷ Department of Neurology, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Hirokoji Agaru, Kawaramachi-dori, Kamigyo-ku, Kyoto, 602-8566, Kyoto, Japan.
⁸ Division of Neurology, Kobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe, 650-0017, Hyogo, Japan.
⁹ Department of Molecular Imaging and Theranostics, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, Chiba, 263-8555, Japan.

Abstract

Background: α-Amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) receptor is a primary mediator of fast glutamatergic excitatory signaling in the brain and has been implicated in diverse neuropsychiatric diseases. We recently developed a novel positron emission tomography (PET) ligand, 2-(1-(3-([¹¹C]methylamino)phenyl)-2-oxo-5-(pyrimidin-2-yl)-1,2-dihydropyridin-3-yl) benzonitrile ([¹¹C]HMS011). This compound is a radiolabelled derivative of perampanel, an antiepileptic drug acting on AMPA receptors, and was demonstrated to have promising in vivo properties in the rat and monkey brains. In the current study, we performed a human PET study using [¹¹C]HMS011 to evaluate its safety and kinetics. Four healthy male subjects underwent a 120-min PET scan after injection of [¹¹C]HMS011. Arterial blood sampling and metabolite analysis were performed to obtain parent input functions for three of the subjects using high-performance liquid chromatography. Regional distribution volumes (V _Ts) were calculated based on kinetic models with and without considering radiometabolite in the brain. The binding was also quantified using a reference tissue model with white matter as reference.

Results: Brain uptake of [¹¹C]HMS011 was observed quickly after the injection, followed by a rapid clearance. Three hydrophilic and one lipophilic radiometabolites appeared in the plasma, with notable individual variability. The kinetics in the brain with apparent radioactivity retention suggested that the lipophilic radiometabolite could enter the brain. A dual-input graphical model, an analytical model designed in consideration of a radiometabolite entering the brain, well described the kinetics of [¹¹C]HMS011. A reference tissue model showed small radioligand binding potential (BP*_ND) values in the cortical regions (BP*_ND = 0-0.15). These data suggested specific binding component of [¹¹C]HMS011 in the brain.

Conclusions: Kinetic analyses support some specific binding of [¹¹C]HMS011 in the human cortex. However, this ligand may not be suitable for practical AMPA receptor PET imaging due to the small dynamic range and metabolite in the brain.

Keywords: AMPA; Interspecies differences; PET; Perampanel; [11C]HMS011.