Regional effects of gantenerumab on neuroimaging biomarkers in the DIAN-TU-001 trial.

INTRODUCTION

Monoclonal anti-amyloid therapies are now accessible, but how these treatments influence changes within the brain is still not clear. We investigated overall and regional change in amyloid removal, glucose metabolism, and atrophy in trial participants with dominantly inherited Alzheimer's disease (DIAD).

METHODS

In the DIAN-TU-001 trial, 92 carriers received gantenerumab or placebo and underwent serial neuroimaging assessments including [11C]-Pittsburgh compound-B (PiB) positron emission tomography (PET), [18F]-fluoro-2-deoxyglucose (FDG) PET, and magnetic resonance imaging (MRI).

RESULTS

Gantenerumab significantly reduced PiB-PET uptake overall and in most regions and showed no changes in FDG-PET or MRI measures. Drug effects were associated with baseline PiB-PET uptake, and the largest effects occurred in medial regions.

DISCUSSION: Treated DIAD participants, and especially those with higher amyloid burden, showed a decrease in PiB-PET uptake, which was more pronounced in the basal ganglia and medial frontal structures. These results may inform patient response and future drug trial design.

HIGHLIGHTS: Gantenerumab unevenly decreased Aβ burden as measured by PiB-PET across brain regions. The strongest decrease in PiB-PET uptake was in basal ganglia and medial frontal structures. Variable drug effect on Aβ was partly due to the amount of burden present before treatment. There was no regional effect on FDG-PET metabolism or MRI volumetrics after 4 years.