Anti-Amyloid Alzheimer's Drugs Show 'Trivial' Effect: Review
SkimNews Take
The drugs' "trivial" benefits, despite addressing a core pathological marker, suggest a more complex etiology or that amyloid accumulation is a downstream effect rather than the primary driver of cognitive decline.
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- Cochrane review analyzed 17 clinical trials of seven anti-amyloid drugs — typically 18 months long and involving more than 20,000 people with mild cognitive impairment or dementia — and found 'no clinically meaningful effect on cognitive decline or dementia severity'
- Edo Richard, co-author and neurology professor at Radboud University medical centre, said effect sizes were 'too small for patients and caregivers to notice' and that the drugs caused more brain swelling and bleeding than the placebo
- Anti-amyloid treatment is logistically 'burdensome,' per Richard — patients must visit a clinic every two to four weeks for IV infusions and undergo regular MRI scans to monitor for brain swelling or bleeding
- Critics including Prof Charles Marshall of Queen Mary University of London and Dr Susan Kohlhaas of Alzheimer's Research UK argued the review pooled results from older, failed drugs with newer, more effective ones — only two of the 17 studies covered lecanemab and donanemab, the medicines now approved in the UK
- NICE rejected lecanemab and donanemab for NHS use on cost grounds despite acknowledging the drugs slow disease progression by four to six months, and is revisiting the decision after an appeal by manufacturers
- Robert Howard, professor of old age psychiatry at UCL, said 'even the best-performing drugs don't do anything that's clinically meaningful' and warned against raising patient expectations
Why it matters: The verdict lands as health systems weigh whether to fund expensive anti-amyloid infusions that regulators approved but NICE rejected on cost grounds. If the Cochrane conclusion holds, the case for public funding of lecanemab and donanemab weakens further — patients would face a burdensome regimen delivering marginal cognitive gains alongside real safety risks from brain swelling and bleeding.
