Dr. Susanne Ostrowitzki of the F. Hoffmann-La Roche Ltd., Neuroscience in Basel, Switzerland, and colleagues said the study involved study subjects, who had mild-to-moderate Alzheimer's disease, at three university medical centers.
Two consecutive groups of patients were randomized to receive two to seven infusions of intravenous gantenerumab -- 60 mg or 200 mg -- or placebo every four weeks.
Additionally, brain tissue from two patients who had Alzheimer's disease -- tissue obtained during tumor surgery -- was examined.
"Our study demonstrates that two to seven months of treatment with gantenerumab led to dose-dependent amyloid reduction in the brains of patients with Alzheimer's disease," the study authors said in a statement. "Additionally, our findings in the placebo-treated patients support previous reports indicating that amyloid load continues to increase in many patients with mild-to-moderate Alzheimer's disease."
The authors suggest the treatment may work through an "effector cell-mediated mechanism of action" but it is unclear whether any reduction in brain amyloid level will translate into patient improvement.
"A phase two clinical trial is under way to investigate whether a clinical benefit can be achieved in gantenerumab-treated patients with early symptoms of Alzheimer's disease," the researchers said.
The findings are published in Online First by Archives of Neurology.