Eligibility for lecanemab and donanemab in Korea under Appropriate Use Recommendations

Appropriate Use Recommendations (AURs) guide real-world use of lecanemab and donanemab in early symptomatic Alzheimer's disease (AD), but their applicability to Asian populations with diverse education backgrounds remains unclear.

Among 2726 participants who visited a Korean memory clinic, 1005 amyloid-positive participants with magnetic resonance imaging (MRI) and Clinical Dementia Rating data were included. Eligibility for lecanemab and donanemab was assessed using AUR criteria, including age, Mini-Mental State Examination (MMSE), brain MRI, apolipoprotein E genotype (for donanemab), and anticoagulant use, applying both raw and z-score-based MMSE thresholds.

Among 1005 amyloid-positive participants, 24.6% were eligible for lecanemab and 28.0% for donanemab (9.1% and 10.3% of the initial sample). Applying MMSE z-scores increased eligibility to 38.4% and 33.7%, respectively. Over a third of participants were excluded due to MRI findings, mainly vascular lesions associated with increased amyloid-related imaging-abnormality risks.

Incorporating demographically adjusted MMSE z-score threshold improves real-world eligibility and promotes equitable access to anti-amyloid therapies.

About a fourth of A+ patients in Korea met AUR criteria for anti-amyloid therapy. Donanemab eligibility slightly exceeded lecanemab despite narrower age criteria. MMSE z-score adjustment increased eligibility in older, less-educated individuals. Over 30% of eligible patients were excluded due to ARIA-related MRI findings. Culturally adapted cognitive thresholds are essential for equitable treatment access.