‘Breakthrough’ dementia drugs do not work, report finds

A major review has found that new Alzheimer’s drugs hailed as breakthroughs may offer only limited benefits for patients.

Treatments including donanemab and lecanemab have been shown in clinical trials to slow cognitive decline in early Alzheimer’s disease, marking the first time any drug has affected the underlying disease process.

However, the latest analysis suggests the impact may be too small to make a meaningful difference to patients’ daily lives.

Researchers from the Cochrane Collaboration reviewed 17 trials involving more than 20,000 patients taking drugs designed to remove amyloid protein from the brain.

They concluded that while the treatments can slow the progression of Alzheimer’s disease, the effect is ‘well below’ what would be needed for patients to notice a clear benefit.

The drugs were also linked to risks, including brain swelling and bleeding, and require regular infusions every two to four weeks.

Private treatment can cost tens of thousands of pounds a year, putting it out of reach for most patients.

The National Institute for Health and Care Excellence has so far declined to offer the drugs on the NHS, citing limited benefits relative to their cost.

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One of the study’s authors, Professor Edo Richard, said he would be cautious about recommending the treatments to patients, warning they may be burdensome without offering significant real-world improvement.

The findings have been supported by some long-standing critics. Professor Robert Howard said the drugs had been ‘hyped’ in a way not supported by robust evidence.

However, the conclusions have sparked strong disagreement among other experts.

Critics of the review argue it combines older failed treatments with newer drugs that have shown measurable, if modest, benefits.

Professor Bart De Strooper said the analysis ‘does not clarify the evidence, it blurs it’, adding that newer drugs have delivered ‘modest yet real clinical benefit’.

Dr Richard Oakley, associate director of research and innovation at the Alzheimer’s Society, said it was important to interpret the findings with nuance.

‘It’s not the case that all amyloid-targeting drugs are ineffective,’ he said. ‘This review makes the picture look bleaker than it really is… newer drugs such as lecanemab and donanemab have shown modest but meaningful benefit.’