On October 25, 2025, Health Canada approved lecanemab, marketed as Leqembi, making it the first disease-modifying treatment for Alzheimer's disease available to Canadian patients. Unlike existing Alzheimer's medications that manage symptoms, lecanemab targets the underlying pathology of the disease by clearing amyloid-beta plaques from the brain.
A New Category of Treatment
For decades, Alzheimer's treatment options have been limited to cholinesterase inhibitors (donepezil, rivastigmine, galantamine) and memantine. These drugs help manage cognitive and behavioral symptoms but do nothing to slow the progression of the disease itself.
Lecanemab represents a fundamentally different approach. It is a humanized monoclonal antibody that binds to soluble amyloid-beta protofibrils, the toxic aggregates believed to drive neurodegeneration in Alzheimer's disease. By clearing these protofibrils, the drug aims to slow cognitive and functional decline rather than merely mask symptoms.
In the pivotal CLARITY AD trial, lecanemab reduced clinical decline by 27% compared to placebo over 18 months, as measured by the CDR-SB (Clinical Dementia Rating-Sum of Boxes) scale. Brain amyloid levels dropped significantly, with some participants reaching amyloid-negative status.
Who Is Eligible
Health Canada's approval is specific. Lecanemab is indicated for patients with mild cognitive impairment (MCI) due to Alzheimer's disease or mild Alzheimer's disease dementia, with confirmed amyloid pathology demonstrated through PET imaging or cerebrospinal fluid biomarkers.
There is an important genetic consideration. The approval applies to ApoE e4 non-carriers or heterozygous carriers. Homozygous ApoE e4 carriers (those with two copies of the e4 allele) face a substantially higher risk of amyloid-related imaging abnormalities (ARIA), particularly ARIA-E (edema) and ARIA-H (hemorrhage). For this group, the risk-benefit profile is less favorable, and prescribers must exercise careful judgment.
Patients require ApoE genotyping before treatment initiation, along with baseline MRI and regular MRI monitoring throughout the treatment course.
Cost and Access Challenges
Lecanemab carries an estimated annual cost of approximately $32,000 CAD per patient. The drug is administered as an intravenous infusion every two weeks, requiring access to infusion clinics or hospital outpatient settings.
On February 19, 2026, the Canadian Drug Agency (CDA-AMC), formerly CADTH, issued its recommendation against public coverage of lecanemab by provincial and territorial drug plans. The agency cited the modest clinical benefit relative to the high cost, the significant monitoring requirements, and the risk of serious adverse events including ARIA.
This recommendation does not prevent individual patients from accessing lecanemab through private insurance, out-of-pocket payment, or manufacturer patient support programs. However, it does mean that most Canadians will not have the drug covered through their provincial formulary, at least for now.
The Broader Pipeline
Lecanemab is not the only anti-amyloid therapy under review. Donanemab (Kisunla), developed by Eli Lilly, targets a different form of amyloid-beta (N3pG amyloid) and showed a 35% slowing of decline in the TRAILBLAZER-ALZ 2 trial. Health Canada's review of donanemab is ongoing, with a decision possible in Q1 2026.
If approved, donanemab could offer a different treatment profile. In clinical trials, many patients were able to stop infusions once their amyloid levels dropped below a certain threshold, potentially reducing the long-term treatment burden.
What This Means for Canadian Patients and Pharmacists
The approval of lecanemab opens a new chapter in Alzheimer's care, but it also introduces complexity. Pharmacists will need to understand the eligibility criteria, the monitoring requirements, and the logistics of biologic infusion therapies. Patient counseling will need to address realistic expectations, as lecanemab slows decline rather than reversing it, and the benefits, while statistically significant, are modest in absolute terms.
For families affected by Alzheimer's disease, the availability of a disease-modifying option, even an imperfect one, represents genuine progress. The challenge ahead lies in ensuring equitable access and integrating these new therapies into a healthcare system that is still adapting to their implications.