Real-world Implementation of Lecanemab in Korean Patients at a Tertiary Memory Clinic: Safety, ARIA Risk, and Early Treatment Patterns.

INTRODUCTION:Lecanemab has demonstrated clinical efficacy in early Alzheimer's disease (AD), but real-world data remain limited, particularly in Asian populations. METHODS:We prospectively enrolled 127 patients across the AD continuum who initiated lecanemab at a tertiary memory clinic in Korea. Infusion-related reactions (IRRs), amyloid-related imaging abnormalities (ARIAs), and cognitive outcomes were evaluated through clinical assessments, serial magnetic resonance imaging (MRI), and longitudinal Mini-Mental State Examination (MMSE) follow-up. RESULTS:Among 127 patients, 102 completed at least five infusions with follow-up MRI. IRRs occurred in 27 (21.3%) patients, primarily during the first infusion. ARIAs occurred in 9 of 102 (8.8%), including ARIAs with edema in 4 (3.9%) and ARIA with hemorrhage in 7 (6.9%); most events were mild or asymptomatic. Higher microbleed burden and white matter hyperintensity were associated with increased ARIA risk. MMSE scores remained stable over 6 months. DISCUSSION:In this prospective Korean cohort, lecanemab was generally well tolerated. Longer term controlled studies are needed to clarify cognitive outcomes.