Anti-Amyloid Monoclonal Antibodies in Early Alzheimer's Disease: Benefits and Safety Signals

Anti-amyloid monoclonal antibodies are the first disease-modifying treatments to show a measurable slowing of clinical decline in early Alzheimer's disease. This review, which reports no new data, summarises the published literature on the amyloid rationale, the earlier antibodies that failed, the main trials of aducanumab, lecanemab and donanemab, and the safety signals that accompany them, above all amyloid-related imaging abnormalities. Benefits are real but modest in absolute terms, and they depend on careful biomarker-based selection and regular MRI monitoring. Safety risks are higher in carriers of the APOE ε4 allele. Evidence beyond 18 months, in diverse populations and against alternative strategies is still lacking, and practical delivery poses serious problems for health services.