A recent comprehensive review has cast doubt on the significant real-world benefits of new Alzheimer's drugs, including donanemab and lecanemab. While these treatments have been heralded as breakthroughs for their ability to slow cognitive decline in early Alzheimer's disease and affect the underlying disease process by targeting amyloid protein, a major analysis suggests their impact on patients' daily lives may be too small to be meaningful.

Conducted by the Cochrane Collaboration, the review analyzed 17 trials involving over 20,000 patients. Researchers concluded that despite the drugs' ability to slow disease progression, the effect is 'well below' what patients would perceive as a clear benefit. Furthermore, these treatments come with considerable risks, such as brain swelling and bleeding, and necessitate regular infusions every two to four weeks. The high cost, potentially tens of thousands of pounds annually for private treatment, also makes them inaccessible for most patients, leading the National Institute for Health and Care Excellence to decline their offer on the NHS due to limited benefits relative to their expense.

One of the study's authors, Professor Edo Richard, expressed caution regarding recommending these treatments, highlighting their potential to be burdensome without offering substantial real-world improvement. This sentiment was echoed by long-standing critics, including Professor Robert Howard, who described the drugs as 'hyped' beyond robust evidence.

However, the review's conclusions have ignited strong disagreement among other experts. Critics argue that the analysis improperly conflates older, failed treatments with newer drugs that have demonstrated measurable, albeit modest, benefits. Professor Bart De Strooper contended that the analysis 'does not clarify the evidence, it blurs it,' asserting that the newer drugs have indeed delivered 'modest yet real clinical benefit.' Dr Richard Oakley, associate director of research and innovation at the Alzheimer's Society, urged a nuanced interpretation, stating that 'It's not the case that all amyloid-targeting drugs are ineffective' and that 'This review makes the picture look bleaker than it really is… newer drugs such as lecanemab and donanemab have shown modest but meaningful benefit.'