General Discussion

Lecanemab, sold under the brand name Leqembi, is a monoclonal antibody medication used for the treatment of Alzheimer's disease.[2][6] Lecanemab is an amyloid beta-directed antibody.[2]

It is given via intravenous infusion or subcutaneous injection to people with mild cognitive impairment or mild dementia.[2] In clinical trials, it demonstrated modest efficacy in reducing relative cognitive decline compared to placebo.[7]

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.[8]

Lecanemab was jointly developed by Eisai, Biogen, and BioArctic.[9] It was granted accelerated approval for medical use in the United States in January 2023,[10] and fully approved by the FDA in July 2023.[6][11]

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Lecanemab is indicated for the treatment of Alzheimer's disease in people who have mild cognitive impairment or mild dementia, but not in people who already have moderate or severe dementia.[2][6][8]

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Lecanemab may cause amyloid-related imaging abnormalities (ARIA). ARIA is often asymptomatic, but serious and life-threatening events rarely may occur. ARIA most commonly presents as temporary swelling of the brain that usually resolves over time and may be accompanied by small spots of bleeding in or on the surface of the brain, though some people may have symptoms such as headache, confusion, dizziness, vision changes, nausea and seizure.[6][8] Compared to placebo, all doses of the drug caused accelerated brain shrinkage.[18]