Feasibility of Leqembi Treatment Supported by Real-World Data from Specialty Memory Clinic

One specialty memory clinic found that it was feasible and manageable to treat people with early symptomatic Alzheimer disease (AD) using Leqembi (lecanemab-irmb; Eisai, Tokyo, Japan; Biogen, Cambridge, MA), according to results of a retrospective analysis published in JAMA Neurology. This clinic, the Washington University Memory Diagnostic Center, reported manageable rates of infusion-related reactions and amyloid-related imaging abnormalities (ARIA), with only 9.8% of participants discontinuing treatment.

The study included 234 participants with early symptomatic AD who initiated treatment with Leqembi between August 2023 and October 2024 at Washington Memory Diagnostic Center. Participants were evaluated via apolipoprotein E (APOE) genotyping, amyloid biomarker testing (cerebrospinal fluid [CSF], PET, or high-accuracy plasma testing), and baseline MRI. Participants received follow-up evaluation for ARIA with MRI monitoring performed after the fourth, seventh, and fourteenth infusions of Leqembi, and individuals were also assessed for infusion-related reactions, with outcomes tracked until December 2024.

Key findings include the following:

• 87 participants (37%) experienced infusion-related reactions, which were mostly mild.
• The pretreatment protocol was changed in July 2024 to include loratadine and acetaminophen prior to the initial Leqembi infusions, and the proportion of participants experiencing infusion-related reactions subsequently decreased to 27%.
• 42 participants (22%) developed ARIA, including 29 (15%) with ARIA-E with or without ARIA-H and 13 (6.7%) with only ARIA-H.
• 11 participants (5.7%) showed symptomatic ARIA, and 2 of these individuals (1.0%) experienced clinically severe events.
• People with a diagnosis of mild dementia at baseline had a 27% symptomatic ARIA rate compared with a 1.8% rate of ARIA reported in those diagnosed with either mild cognitive impairment or very mild dementia at baseline.
• APOE ε4 homozygosity was linked to an increased risk of developing ARIA-E.
• 9.8% of participants discontinued treatment, with 4.3% of these resulting from ARIA.

The authors highlighted some limitations of the study including a lack of diversity in the participant population and the fact that the study took place in a single clinic.