Abstract
Background: Lecanemab, an antiamyloid monoclonal antibody, has emerged as a treatment option for Alzheimer disease. However, there is a pressing need for real-world evidence to inform clinical practice, particularly regarding its safety profile. Objectives: This study aimed to analyze adverse events (AEs) associated with lecanemab using the Food and Drug Administration Adverse Event Reporting System (FAERS) database. Methods: All cases reporting AEs were included if reported during the study period, from January 1, 2023, to June 30, 2024, during which a total of 1,307,937 cases were reported in the FAERS database. A disproportionality analysis was conducted to assess adverse reactions associated with lecanemab. Reporting odds ratios (RORs) with 95% CIs were extracted from OpenVigil 2.1-MedDRA-v24 for lecanemab-related events. Results: The analysis identified a total of 1679 AEs associated with lecanemab during the study period. The strongest safety signal was observed for amyloid-related imaging abnormalities (ARIAs), particularly ARIA with hemosiderin deposits in the brain parenchyma or on the pial surface (microhemorrhages, ROR 11,221.5 [95% CI 5706.2–22,067.5]) and ARIA with brain edema or sulcal effusion (edema/effusion, ROR 8927.3 [95% CI 5243.6–15,199.1]). Other notable AEs included infusion-related reactions (ROR 24.9 [95% CI 18.9–32.8]), headache (ROR 10.2 [95% CI 8.6–12.2]), and confusional states (ROR 15.0 [95% CI 11.4–19.7]). Conclusion: This study underscores the importance of vigilant monitoring for ARIA and other neurologic and psychiatric AEs associated with lecanemab in real-world clinical settings. The findings highlight the need for ongoing postmarket surveillance to ensure patient safety and guide clinical decision making.