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AC IMMUNE SA filed this Form 20-F on 03/21/2019
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Figure 16: ABBY high dose arm: Change in CDR-SB




Ref: Mackey, et. al., AAIC, 2016


BLAZE Study Design


The BLAZE study was a randomized, double-blind, parallel-group, placebo-controlled study to evaluate the effects of crenezumab on brain amyloid burden as assessed by amyloid PET imaging and other biomarker endpoints in patients with mild to moderate AD. The primary endpoint was to measure the change in brain amyloid load using florbetapir-PET. The terms brain amyloid burden and brain amyloid load refer to the total amount of amyloid deposited in the brain. Each of these typically increases over time in an AD patient. Other endpoints included changes from baseline in other biomarkers (CSF, volumetric MRI), cognition (ADAS-cog12), global function (CDR-Sum of boxes), and activities of daily living (ADCS-ADL). Enrollment required florbetapir-PET positive scans, or patients who were amyloid positive. Ninety-one patients were included in the study.


BLAZE Study Results


The primary end point of change in brain amyloid load by florbetapir-PET was not met, but the study was not powered to detect statistically significant results. When assessing the amyloid load, the amount of amyloid in a region of the brain is determined by comparing the amount of an amyloid tracer to that found in a region with little or no amyloid, such as the cerebellum or the white matter, usually in the cortex. Recent studies have shown that the variability from scan to scan in the same patient over time is much higher when using the cerebellum than with the white matter, making the white matter a more powerful point of comparison for use in longitudinal studies. The higher variability of the cerebellum may be due to difficulties in exact positioning between scans and higher background levels. Taking this into account, the exploratory analyses of the BLAZE amyloid PET results using white matter reference region were conducted independently by two laboratories, the Banner Alzheimer’s Institute and MNI Laboratories. The analyses produced analogous results where a trend in the reduction of Abeta accumulation was observed in the high-dose arm. (Figure 17 below)



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