Donanemab is associated with a modest slowing of Alzheimer disease progression in patients with early symptomatic disease, according to an industry-conducted phase 2 trial published in the New England Journal of Medicine and presented at the International Conference on Alzheimer's and Parkinson's Disease. The experimental treatment is a humanised IgG1 antibody that targets amyloid deposits.
Researchers randomised roughly 250 patients with prodromal Alzheimer's with tau and amyloid deposition to receive either intravenous donanemab or placebo every 4 weeks for up to 72 weeks.
At 76 weeks, the donanemab group had a smaller reduction in a composite score that assessed cognitive and functional ability than the placebo group — a 3.2-point difference on a 144-point scale. The authors caution that they are not certain whether this difference is clinically meaningful.
The donanemab group also had greater reductions in amyloid plaque levels — 60% of recipients were amyloid-negative at 1 year. Amyloid-related imaging abnormalities with oedema or effusions were more common in the treatment group (27% vs. 1% for placebo).