Preclinical Properties of 18F-AV-45: A PET Agent for Aβ Plaques in the Brain

Journal of Nuclear Medicine

Daniel Skovronsky¹  Wei Zhang¹  Michael R. Kilbourn¹  Tyler E. Benedum¹  Hank F. Kung¹  Nathaniel Lim¹  Franz Hefti¹  Seok Rye Choi¹  Geoff Golding¹  Zhiping Zhuang¹ 

关键词: PET imaging;    Alzheimer disease;    β-amyloid plaque;    autoradiography;    biodistribution;   

DOI  :  10.2967/jnumed.109.065284

学科分类：医学（综合）

来源: Society of Nuclear Medicine

【 摘 要 】

β-amyloid plaques (Aβ plaques) in the brain, containing predominantly fibrillary Aβ peptide aggregates, represent a defining pathologic feature of Alzheimer disease (AD). Imaging agents targeting the Aβ plaques in the living human brain are potentially valuable as biomarkers of pathogenesis processes in AD. (E)-4-(2-(6-(2-(2-(2-18F-fluoroethoxy)ethoxy)ethoxy)pyridin-3-yl)vinyl)-N-methyl benzenamine (18F-AV-45) is such as an agent currently in phase III clinical studies for PET of Aβ plaques in the brain. Methods: In vitro binding of 18F-AV-45 to Aβ plaques in the postmortem AD brain tissue was evaluated by in vitro binding assay and autoradiography. In vivo biodistribution of 18F-AV-45 in mice and ex vivo autoradiography of AD transgenic mice (APPswe/PSEN1) with Aβ aggregates in the brain were performed. Small-animal PET of a monkey brain after an intravenous injection of 18F-AV-45 was evaluated. Results: 18F-AV-45 displayed a high binding affinity and specificity to Aβ plaques (Kd, 3.72 ± 0.30 nM). In vitro autoradiography of postmortem human brain sections showed substantial plaque labeling in AD brains and not in the control brains. Initial high brain uptake and rapid washout from the brain of healthy mice and monkey were observed. Metabolites produced in the blood of healthy mice after an intravenous injection were identified. 18F-AV-45 displayed excellent binding affinity to Aβ plaques in the AD brain by ex vivo autoradiography in transgenic AD model mice. The results lend support that 18F-AV-45 may be a useful PET agent for detecting Aβ plaques in the living human brain.

【 授权许可】

Unknown