Alzheimer's Drugs Deemed 'Trivial' in Effectiveness, Review Finds

A recent Cochrane review analyzing 17 clinical trials involving over 20,000 people with mild cognitive impairment or dementia has concluded that anti-amyloid drugs have a 'trivial' effect on cognition and dementia severity over 18 months.

The review, which assessed seven anti-amyloid drugs, found that improvements in functional ability were 'small at best' and that the drugs caused more swelling and bleeding in the brain than the placebo.

The findings are a blow to the new wave of drugs designed to slow Alzheimer's by clearing clumps of amyloid protein that build up in the brain. Despite initial hype, with some regulators approving drugs like lcanemab and donanemab, many countries have stopped short of providing them through public health services due to concerns over their effectiveness and cost.

Critics of the review argue that it combines results from older, failed drugs with those from newer, more effective medicines, which may skew the conclusions. However, the review's authors defend their approach, stating that all the drugs aimed to remove amyloid from the brain and assessed the impact on patients in a similar way.

The review's lead author, Edo Richard, notes that the effect sizes are too small for patients and caregivers to notice, and that the drugs are also 'burdensome' due to the need for regular intravenous drug infusions and MRI scans.

Experts in the field, such as Robert Howard, express concerns that the drugs may not truly alter the course of Alzheimer's, and that it's unfair to raise expectations in patients. Meanwhile, Alzheimer's Research UK argues that the review's conclusions are limited by its methodology and that anti-amyloid treatments will not be the whole answer to curing Alzheimer's.