Eligibility for Lecanemab Treatment in the Republic of Korea: Real-World Data From Memory Clinics

Abstract

Background and purpose: We aimed to determine the proportion of Korean patients with early Alzheimer's disease (AD) who are eligible to receive lecanemab based on the United States Appropriate Use Recommendations (US AUR), and also identify the barriers to this treatment.

Methods: We retrospectively enrolled 6,132 patients with amnestic mild cognitive impairment or mild amnestic dementia at 13 hospitals from June 2023 to May 2024. Among them, 2,058 patients underwent amyloid positron emission tomography (PET) and 1,199 (58.3%) of these patients were amyloid-positive on PET. We excluded 732 patients who did not undergo brain magnetic resonance imaging between June 2023 and May 2024. Finally, 467 patients were included in the present study.

Results: When applying the criteria of the US AUR, approximately 50% of patients with early AD were eligible to receive lecanemab treatment. Among the 467 included patients, 36.8% did not meet the inclusion criterion of a Mini-Mental State Examination (MMSE) score of ≥22.

Conclusions: Eligibility for lecanemab treatment was not restricted to Korean patients with early AD except for those with an MMSE score of ≥22. The MMSE criteria should therefore be reconsidered in areas with a higher proportion of older people, who tend to have lower levels of education.

Keywords: Alzheimer's disease; Korean; Mini-Mental State Examination; eligibility; lecanemab.

Fig. 1. Study-population flowchart. AD, Alzheimer’s disease; CSF, cerebrospinal fluid; MCI, mild cognitive impairment; MRI, magnetic resonance imaging; PET, positron-emission tomography.

Fig. 2. Prevalence based on the number of exclusion criteria met among patients who met the inclusion criteria of the US Appropriate Use Recommendations produced by the US Alzheimer’s Disease and Related Disorders Therapeutics Work Group.