LEQEMBI Real-World Study Finds Over 75% of Early Alzheimer's Patients Remained Stable or Improved

Tokyo and Cambridge, Mass. – July 14, 2026 – Eisai Co., Ltd. and Biogen Inc. have released findings from the real-world LEADER Study on Lecanemab in Early Alzheimer's Disease (AD). The study indicates that nearly 83% of patients with early AD remained stable (75.9%) or showed improvement (6.6%) during an average of 17 months of LEQEMBI® treatment.

The data, presented at the Alzheimer's Association International Conference® (AAIC®) 2026 in London, support the long-term benefits of continuous LEQEMBI treatment and offer insights into the treatment experience in clinical settings outside of formal trials. The results were consistent across sex, race, ethnicity, and APOE genotype.

The LEADER Study is a three-year, multicenter, retrospective real-world study designed to examine LEQEMBI utilization, treatment persistence, safety, and cognitive and functional assessments in diverse U.S. clinical settings. This interim analysis included 432 patients with early AD who received at least seven LEQEMBI infusions.

Key findings indicate that nearly 87% of patients opted to continue LEQEMBI therapy. Safety observations, including amyloid-related imaging abnormalities (ARIA), were consistent with the U.S. FDA-approved label. ARIA was observed in 12.3% of patients, with most cases being asymptomatic and mild in severity.