A Study to Confirm Safety and Efficacy of Lecanemab in Participants With Early Alzheimer's Disease

Summary

This study will be conducted to evaluate the efficacy of lecanemab in participants with early Alzheimer's disease (EAD) by determining the superiority of lecanemab compared with placebo on the change from baseline in the Clinical Dementia Rating-Sum of Boxes (CDR-SB) at 18 months of treatment in the Core Study. This study will also evaluate the long-term safety and tolerability of lecanemab in participants with EAD in the Extension Phase and whether the long-term effects of lecanemab as measured by the CDR-SB at the end of the Core Study is maintained over time in the Extension Phase. Extension Phase Part B will continue dosing with lecanemab in countries where lecanemab may not be commercially available.

Timeline

Start

2019-03-27

Primary completion

2029-06-30

Completion

2029-06-30

Publications

• Perry R, Kipps C, Soto Martin ME, Bozzali M, Logroscino G, Trafford S, Dhadda S, Kanekiyo M, Goodwin A, Hodgkinson M, Hersch S, Irizarry M, Kramer L, Froelich L. Lecanemab for treatment of individuals with early Alzheimer's Disease (AD) who are apolipoprotein E epsilon4 (ApoE epsilon4) non-carriers or heterozygotes. J Prev Alzheimers Dis. 2026 Apr;13(4):100507. doi: 10.1016/j.tjpad.2026.100507. Epub 2026 Feb 13.
• Devanarayan V, Horie K, Wildsmith K, Doherty T, Andreozzi E, Charil A, Sachdev P, Kramer LD, Dhadda S, Irizarry MC. Combining CSF MTBR-tau243 and plasma pTau217 ratio enhances the prediction of continuous regional tau PET burden in early Alzheimer's disease. Alzheimers Dement. 2025 Nov;21(11):e70881. doi: 10.1002/alz.70881.
• Devanarayan V, Ye Y, Zhu L, Tian L, Kramer L, Irizarry M, Dhadda S. Predicted natural progression as an Alzheimer's prognostic covariate improves the precision of lecanemab efficacy assessments and clinical trial efficiency. Alzheimers Dement. 2025 Mar;21(3):e70045. doi: 10.1002/alz.70045.
• Devanarayan V, Charil A, Horie K, Doherty T, Llano DA, Andreozzi E, Sachdev P, Ye Y, Murali LK, Zhou J, Reyderman L, Hampel H, Kramer LD, Dhadda S, Irizarry MC; Alzheimer's Disease Neuroimaging Initiative (ADNI). Plasma pTau217 ratio predicts continuous regional brain tau accumulation in amyloid-positive early Alzheimer's disease. Alzheimers Dement. 2025 Feb;21(2):e14411. doi: 10.1002/alz.14411. Epub 2024 Nov 22.
• Devanarayan V, Doherty T, Charil A, Sachdev P, Ye Y, Murali LK, Llano DA, Zhou J, Reyderman L, Hampel H, Kramer LD, Dhadda S, Irizarry MC. Plasma pTau217 predicts continuous brain amyloid levels in preclinical and early Alzheimer's disease. Alzheimers Dement. 2024 Aug;20(8):5617-5628. doi: 10.1002/alz.14073. Epub 2024 Jun 28.
• Honig LS, Sabbagh MN, van Dyck CH, Sperling RA, Hersch S, Matta A, Giorgi L, Gee M, Kanekiyo M, Li D, Purcell D, Dhadda S, Irizarry M, Kramer L. Updated safety results from phase 3 lecanemab study in early Alzheimer's disease. Alzheimers Res Ther. 2024 May 10;16(1):105. doi: 10.1186/s13195-024-01441-8.
• Tahami Monfared AA, Ye W, Sardesai A, Folse H, Chavan A, Aruffo E, Zhang Q. A Path to Improved Alzheimer's Care: Simulating Long-Term Health Outcomes of Lecanemab in Early Alzheimer's Disease from the CLARITY AD Trial. Neurol Ther. 2023 Jun;12(3):863-881. doi: 10.1007/s40120-023-00473-w. Epub 2023 Apr 2.
• van Dyck CH, Swanson CJ, Aisen P, Bateman RJ, Chen C, Gee M, Kanekiyo M, Li D, Reyderman L, Cohen S, Froelich L, Katayama S, Sabbagh M, Vellas B, Watson D, Dhadda S, Irizarry M, Kramer LD, Iwatsubo T. Lecanemab in Early Alzheimer's Disease. N Engl J Med. 2023 Jan 5;388(1):9-21. doi: 10.1056/NEJMoa2212948. Epub 2022 Nov 29.

Drugs

Indications