Canada gives conditional OK to early Alzheimer’s drug Leqembi
Treatment removes toxic proteins from brain, targeting disease cause
Health Canada has conditionally approved Leqembi (lecanemab) for certain adults with early Alzheimer’s disease, making it the first treatment approved in Canada that targets an underlying cause of early Alzheimer’s by removing toxic amyloid-beta proteins from the brain.
The therapy, co-developed by Eisai and Biogen, was cleared for patients with mild cognitive impairment or mild dementia due to Alzheimer’s.
Patients must also carry no copies or one copy of the apolipoprotein E4 (ApoE4) genetic variant, which may increase the risk of side effects, and show amyloid-beta accumulation — a hallmark of Alzheimer’s disease.
The approval was based on data from the Phase 3 Clarity AD trial (NCT03887455), in which Leqembi significantly reduced toxic amyloid-beta plaques in the brain and slowed cognitive and functional decline compared with a placebo.
Full approval will depend on additional data confirming Leqembi’s clinical benefit.
‘Timely intervention is our most powerful tool’
“Today marks an important milestone for the Canadian Alzheimer’s community, providing much needed hope to the many families affected by this unforgiving disease,” Eric Tse, general manager at Biogen Canada, said in a joint press release from the companies. “Timely intervention is our most powerful tool in the fight against Alzheimer’s. By detecting and appropriately treating early AD [Alzheimer’s disease], we can empower patients, families and healthcare providers to take action sooner to help preserve cognitive abilities and activities of daily living.”
Alzheimer’s is caused when amyloid-beta accumulates in the brain and forms sticky clumps, or plaques, that disrupt nerve cell function and eventually cause nerve cell death.
Leqembi is an antibody designed to clear these plaques, which is expected to slow disease progression. The therapy can target both protofibrils — soluble forms of amyloid-beta aggregates that are prone to form plaques and are considered the most toxic form of amyloid-beta — and fibrils, which are the insoluble aggregates that make up amyloid plaques.
The Clarity AD trial evaluated Leqembi against a placebo in 1,795 people with early Alzheimer’s, defined as mild cognitive impairment due to disease or mild Alzheimer’s dementia, with confirmed amyloid buildup in the brain.
The main goal was to show that Leqembi could slow the progression of dementia, as assessed by the Clinical Dementia Rating-Sum of Boxes (CDR-SB), after 18 months of treatment. Data showed a significant, 27% relative slowing of dementia progression in people given the therapy.
The therapy also met all key secondary endpoints, slowing disease progression in other measures of disease severity and leading to marked reductions in amyloid plaques on PET imaging scans.
These findings make Leqembi the first approved treatment shown to reduce disease progression and to slow cognitive and functional decline in adults with Alzheimer’s.
“This decision is a welcome step forward, marking the first time there is an approved treatment that slows the relentless decline in those living with this devastating disease,” said Sharon Cohen, MD, a neurologist and medical director at Toronto Memory Program.
Cathy Barrick, CEO of Alzheimer Society of Ontario, said Leqembi and treatments like it “may offer time to people at the earlier stages of Alzheimer’s disease–time to continue to make and enjoy memories with those closest to them.”
“We share the hope and excitement of hundreds of thousands of Canadians impacted by Alzheimer’s disease,” Barrick said. She urged all provinces to “act now so that Alzheimer’s disease is treated with urgency, compassion, and comprehensive care.”
Eisai, which will distribute Leqembi in Canada, plans to collect and submit additional data from patients treated in real-world clinical settings to confirm the treatment’s long-term benefits.
“Alzheimer’s disease has a profound impact on those living with the condition, their families, care partners and the health system at large,” said Pat Forsythe, vice president and general manager at Eisai. “We will continue to work with all stakeholders to ensure timely access to Leqembi for patients across Canada, and to support diagnosis and treatment for early AD.”
Leqembi received full approval in the U.S. in 2023, following accelerated approval from the Food and Drug Administration (FDA) earlier that year.
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