TY - JOUR T1 - Tau Accumulation Over One Year Measured with F-18 MK6240 PET. JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 285 LP - 285 VL - 61 IS - supplement 1 AU - Christopher Rowe AU - Vincent Dore AU - Natasha Krishnadas AU - Rachel Mulligan AU - Regan Tyrrell AU - Samantha Burnham AU - Victor Villemagne Y1 - 2020/05/01 UR - http://jnm.snmjournals.org/content/61/supplement_1/285.abstract N2 - 285Introduction: Understanding the rate of tau progression in Alzheimer’s disease (AD) enables optimal design of clinical trials of anti-tau agents. Follow-up studies of 12-18 months with the tau tracer Flortaucipir (F-18 AV1451) have reported no increase in amyloid (Aβ) -ve cognitively normal (CN), 0.5% increase in Aβ+ve CN, mainly in entorhinal and posterior cingulate areas, and widespread cortical 3% increase in Aβ+ve MCI or dementia. Increase was greater with higher baseline tau and younger age. F-18 MK6240 is a new tau tracer with high target to background binding and no choroid plexus uptake, making it attractive for use in clinical trials. We aimed to define regional rates of MK6240 accumulation in CN and AD. Methods: We performed PET acquisition 90-110 minutes post injection of 200 MBq F-18 MK6240 at baseline and 12 months in 13 Aβ-ve CN and 19 Aβ+ve subjects (10 CN, 5 MCI, 4 mild AD). SUVR using cerebellar grey matter as reference was calculated for the medial temporal region (Me) (i.e. entorhinal, amygdala, hippocampus, parahippocampal cortex) and temporoparietal cortex (Te) (i.e. inferolateral temporal, parietal and posterior cingulate cortices). Results: MCI and AD were younger than CN (69.4 ±5 yrs vs 77.5 ±4) and had higher baseline MK6240 binding. Aβ+ve CN had higher baseline binding than Aβ-ve CN in both Me and Te regions. (Table 1) While Aβ-ve CN showed no change, Aβ+ve CN showed a trend increase of 1.6%/yr, and MCI and AD showed an increase of 7-8%/yr in temporoparietal cortex (Table 1, Figure 1). Percentage change was correlated with baseline SUVR and negatively correlated with age. Conclusions: In comparison to published data for flortaucipir, we found greater increase over one year in MK6240 binding in the medial temporal region in preclinical AD (i.e. Aβ+ve CN) (0.5% vs 1.6%) and in temporo-parietal cortex in MCI or AD patients (3% vs 7-8%). However, given the strong relationships of age and baseline tau level to rate of increase, these comparative findings may be due to age selection bias. Recruitment is on-going to address this. ER -