Real-world use of the Alzheimer's drug lecanemab produced rates of amyloid-related imaging abnormalities (ARIA) consistent with clinical trial findings, according to an interim analysis of the LEADER study presented at the American Society of Functional Neuroradiology meeting. The study, which included 432 patients with early Alzheimer's disease who received at least seven biweekly infusions, found any ARIA in 12.3% of patients, compared with 21.3% in the phase III CLARITY AD trial. ARIA-E occurred in 6.5% versus 12.6%, and ARIA-H in 7.6% versus 17.3%.
The median time to ARIA-E was 3.4 months, and results were similar whether patients were scanned on 1.5T or 3T MRI machines. Daryl Rhys Jones of Eisai noted that this suggests MRI field strength does not meaningfully affect detection in real-world practice. The LEADER study includes diverse settings, including general neurologists who were treating patients with lecanemab for the first time, and its ARIA rates were consistent with other real-world evidence such as the ALZ-NET registry.
Jones emphasized that close collaboration between prescribers and radiologists was central to successful monitoring. This involved clear communication not only between neurologists and radiologists but also with front-office and administrative staff, ensuring radiologists understood what to describe so neurologists could decide whether to continue treatment. The analysis included 12 sites, with expansion to 20 sites underway, and the study is now also looking at subcutaneous administration of lecanemab.