Health Canada Approves Donanemab for Early Alzheimer’s Disease

Health Canada has approved donanemab (Kisunla™) for people with mild cognitive impairment (MCI) or early-state Alzheimer’s disease, marking another major development in Alzheimer’s treatment in Canada. Developed by Eli Lilly, donanemab is now the second disease-modifying Alzheimer’s therapy approved in Canada, following the approval of lecanemab (Leqembi) in October 2025 by Eisai and Biogen.

The approval represents an important shift in the Alzheimer’s field after nearly two decades without new treatments that target the underlying biology of the disease. Existing medications such as Donepezil, Rivastigmine, Galantamine, and Memantine can help manage symptoms for some individuals, but they do not slow disease progression. In recent years, advances in Alzheimer’s research, particularly in biomarkers and amyloid-targeting therapies, have led to growing optimism about earlier detection and intervention with subsequent disease modification.

Like lecanemab, donanemab targets amyloid, a protein that accumulates abnormally in the brains of people with Alzheimer’s disease. However, the two therapies work somewhat differently. Lecanemab primarily targets smaller amyloid aggregates and plaques, while donanemab is designed to bind to and remove amyloid plaques already present in the brain.

Clinical trials for both medications showed modest but measurable slowing of cognitive decline in people with early Alzheimer’s disease. In the CLARITY-AD trial, lecanemab slowed decline by about 27% over 18 months compared with placebo. Donanemab showed a slowing of approximately 22% overall in the TRAILBLAZER-ALZ 2 trial, with some patients in the earliest stages experiencing slowing closer to 35%.

The treatments also differ in how they are administered. Lecanemab is given as an intravenous infusion every two weeks on an ongoing basis, while donanemab is given once every four weeks and may be stopped once amyloid plaques are sufficiently cleared. In clinical trials, some individuals receiving donanemab completed treatment within six to twelve months.

Neither therapy is a cure, and both carry important risks that require careful monitoring. The most significant side effect is amyloid-related imaging abnormalities (ARIA), which can involve swelling or bleeding in the brain seen on MRI scans. In clinical trials, lecanemab was associated with brain swelling in about 12% of participants and brain bleeding in approximately 17%. Donanemab showed higher overall ARIA rates, with about 37% of participants experiencing swelling or bleeding. Most of these were noticed on MRI but the patients were asymptomatic (not aware of the side effects). Risk appears highest in individuals carrying two copies of the APOE4 gene, a genetic variant associated with increased Alzheimer’s risk.

The approval of donanemab also comes as discussions continue around access to disease-modifying therapies in Canada. Although lecanemab was approved by Health Canada in 2025, Canada’s Drug Agency (CDA) recently issued a draft recommendation against public reimbursement, citing concerns around cost-effectiveness, health system readiness, and the magnitude of benefit. Donanemab will now undergo a similar reimbursement review process. [Update: August 31, 2026. CDA has issued a final positive recommendation supporting public reimbursement of lecanemab]

For patients and families, the arrival of a second disease-modifying therapy provides another option at a time when treatment choices for Alzheimer’s disease have historically been limited. These approvals also reinforce the growing importance of early diagnosis, since both therapies are intended for people in the earliest stages of disease.

“We are just at the beginning of this new era of disease modification for brain diseases causing dementia. These two drugs are the first out of the gate and hold promise that a brighter future is coming for patients with Alzheimer’s disease and other diseases causing mild cognitive impairment and early stage dementia.” - Dr. Carmela Tartaglia, Executive Director of TDRA, Co-Director and Medical Lead of the Toronto Western Hospital Memory Clinic, and clinician-scientist specializing in neurodegenerative diseases.

While questions remain about long-term implementation, access, and cost, the approval of donanemab reflects continued momentum in Alzheimer’s research and signals a new era in dementia care, one increasingly focused on slowing disease progression and expanding treatment options for patients and families.