Previous findings from the positron emission tomography (PET) substudy of the 
SCarlet RoAD and Marguerite RoAD open-label extension (OLE) showed gantenerumab 
doses up to 1200 mg every 4 weeks administered subcutaneously resulted in robust 
beta-amyloid (Aβ) plaque removal over 24 months in people with 
prodromal-to-moderate Alzheimer's disease (AD). In this 36-month update, we 
demonstrate continued reduction, with mean (standard error) centiloid values at 
36 months of -4.3 (7.5), 0.8 (6.7), and 4.7 (8.0) in the SCarlet RoAD 
(double-blind pooled placebo and active groups), Marguerite RoAD double-blind 
placebo, and Marguerite RoAD double-blind active groups respectively, 
representing a change of -57.0 (10.3), -90.3 (9.0), and -74.9 (10.5) centiloids 
respectively. These results demonstrate that prolonged gantenerumab treatment, 
at doses up to 1200 mg, reduces amyloid plaque levels below the amyloid 
positivity threshold. The ongoing GRADUATE Phase III trials will evaluate 
potential clinical benefits associated with gantenerumab-induced 
amyloid-lowering in people with early (prodromal-to-mild) AD.