Overview

• The Clarity AD open-label extension reported a 1.75-point slowing on the Clinical Dementia Rating-Sum of Boxes scale at four years versus ADNI controls, up from a 1.01-point reduction at three years.
• Compared with the BioFINDER cohort, lecanemab treatment yielded a 2.17-point reduction in cognitive decline at four years, reflecting increasing benefit over time.
• No new safety signals emerged during four years of treatment and rates of amyloid-related imaging abnormalities decreased after the first year before stabilizing.
• Among early-stage patients with low tau pathology, 69% experienced no cognitive decline and 56% saw improvements in their cognitive scores over the extension period.
• The long-term findings underscore the value of early intervention by showing that patients treated before significant tau accumulation derive the most pronounced and sustained benefits.