Lecanemab
| Monoclonal antibody | |
|---|---|
| Type | Whole antibody |
| Source | Humanized |
| Target | Amyloid beta |
| Clinical data | |
| Trade names | Leqembi |
| Other names | BAN2401, lecanemab-irmb |
| AHFS/Drugs.com | Monograph |
| MedlinePlus | a623004 |
| License data | |
| Routes of administration | Intravenous, subcutaneous |
| ATC code | |
| Legal status | |
| Legal status | |
| Identifiers | |
| CAS Number | |
| DrugBank | |
| ChemSpider |
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| UNII | |
| KEGG | |
| Chemical and physical data | |
| Formula | C6544H10088N1744O2032S46 |
| Molar mass | 147181.62 g·mol−1 |
Lecanemab, sold under the brand name Leqembi, is a monoclonal antibody medication used for the treatment of Alzheimer's disease. Lecanemab is an amyloid beta-directed antibody. It is given via intravenous infusion or subcutaneous injection to people with mild cognitive impairment or mild dementia. In clinical trials, it demonstrated modest efficacy in reducing relative cognitive decline compared to placebo. The most common side effects of lecanemab include headache, infusion-related reactions, and amyloid-related imaging abnormalities, a side effect known to occur with the class of antibodies targeting amyloid. Lecanemab was jointly developed by Eisai, Biogen, and Bioarctic.
Lecanemab was granted accelerated approval for medical use in the United States in January 2023, and traditional approval in July 2023. Lecanemab was approved for medical use in South Korea in May 2024, Mexico in December 2024,, the EU in April 2025, and Canada in October 2025.