On October 27th, 2025, Health Canada announced its authorization of lecanemab (brand name LEQEMBI) as a new treatment for mild cognitive impairment (MCI) or mild dementia due to Alzheimer’s Disease.
LEQEMBI is a monoclonal antibody; it works by selectively binding to various components of amyloid-beta (Aβ) plaques, resulting in a reduction of these plaques in the brain. Reducing Aβ in individuals who are early in the disease progression has been shown to slow cognitive decline. During their Phase 3 clinical trial, EISAI found that LEQEMBI reduced cognitive decline in the treatment group by 27% at 18 months compared to the placebo (as evidence by performance on select cognitive evaluations).
While LEQEMBI is the first approved treatment for Alzheimer’s Disease shown to affect disease progression, it will only be offered to individuals who do not carry the ApoE ε4 gene. This is due to the increased risk of experiencing adverse events such as cerebral microhemorrhages, cerebral macrohemorrhages, superficial siderosis, and edema/effusion. Thus, a genetic screening will be required prior to the prescription of this treatment.
Health Canada has yet to release detailed guidelines outlining the prescription, administration, and monitoring of LEQEMBI. When these guidelines are hopefully shared in 2026, they will begin to fill a critical gap in care for aging Canadians, especially those living with Alzheimer’s disease.
