Characteristics of infusion-related reactions to lecanemab in early Alzheimer’s disease: A multicenter real-world study in Northwestern China

Background Infusion-related reactions (IRRs) represent the most common adverse events associated with lecanemab. However, real-world data on IRR characteristics and risk factors in Asian populations, particularly Chinese, remain scarce. Methods In a multicenter prospective registry, 139 patients with early Alzheimer’s disease (AD) receiving lecanemab were included. IRRs were physician-confirmed. Multivariable logistic regression identified independent predictors. Results The cumulative IRR incidence was 12.36 %, highest at the first infusion (17.3 %) and decreased significantly thereafter ( P < 0.001). Fever (54.2 %) and dizziness (16.7 %) were the most common symptoms. 45.8 % of IRRs occurred 2–24 hours after infusion. All IRRs were mild (Grade 1) and self-limited. Hypertension (OR = 5.017, P = 0.007) and higher Fazekas score (OR = 2.734, P = 0.017) were independently associated with IRR. Discussion In this Chinese real‑world cohort, lecanemab‑associated IRRs were less frequent, mild, and delayed. Hypertension and white‑matter hyperintensity severity emerged as key risk factors, underscoring the potential role of cerebrovascular health in IRR susceptibility.