Real-world experience with lecanemab therapy for Alzheimer's disease in the Intermountain West

Introduction: Lecanemab is a monoclonal antibody directed against amyloid plaques that has been FDA approved for the treatment of Alzheimer's disease (AD). Data from pivotal clinical trials demonstrated that treatment with lecanemab reduced amyloid plaque burden and slowed cognitive decline but also increased the incidence of potentially serious amyloid-related imaging abnormalities (ARIA). However, there is relatively little real-world data on lecanemab's efficacy and safety outside of a clinical trial environment. Here, we report on efforts at the University of Utah to administer amyloid-removal therapy in the Intermountain West (Utah, Wyoming, Idaho, and Nevada). Methods: This is a retrospective analysis of patients treated with lecanemab between April 2023 and July 2025 at an academic medical center. Patients with biomarker-confirmed AD were screened in cognitive neurology or geriatrics clinics at the University of Utah. Screening included neurological evaluations, magnetic resonance imaging (MRI), lumbar puncture or amyloid positron emission tomography (PET), and multidisciplinary team consensus discussions. Safety monitoring included routine MRI scans for ARIA, per published guidelines. Results: Between July 2021 and July 2025, over 2300 patients were seen by prescribing providers. As of July 1, 2025, 70 of these patients had received at least one lecanemab infusion. Patients were predominantly from Utah (53/70), but significant numbers of patients were from Idaho (8/70), Wyoming (4/70), Montana (1/70), Nevada (1/70), or Florida (1/70). The average distance to the University of Utah was 118.6 miles. For patient convenience, infusions were arranged locally; thus, only 55/70 patients received infusions at University of Utah infusion centers. In total, we observed 14 cases of ARIA, which was significantly associated with apolipoprotein E (ApoE) genotype. Zero cases of ARIA were symptomatic, and there was no association between geographical location and adverse effects. Discussion: Our study examined the safety and tolerability of lecanemab administration within the Intermountain West region of the United States, utilizing both centralized and distributed infusion sites. Although continued follow up is necessary to establish long-term efficacy and safety, our experience highlights that use of distributed infusion sites increases access to disease-modifying treatment without significant increase in risk to patients.