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Leaders in the dementia field react to a report with ‘major limitations’ labelling Alzheimer’s drugs as ineffective

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Alzheimer's Research UK

On 16 April 2026

Alzheimer’s Research UK has raised concerns with the findings from a new Cochrane review of clinical trial data on different anti-amyloid treatments, that states these medicines show ‘no clinically meaningful benefit’ for people with Alzheimer’s.

The review, which is published today (Thurs 16 April) attempts to assess the impact of anti-amyloid drugs in Alzheimer’s, but many researchers say it has major limitations.

We explain below why the conclusions of the study’s authors may not fully reflect the experiences of people affected by Alzheimer’s.

Does the review mean anti-amyloid drugs are ineffective?

Anti-amyloid drugs are a group of drugs that work by removing amyloid, a protein linked with Alzheimer’s disease. Lecanemab and donanemab, the latest Alzheimer’s drugs licenced in the UK, are anti-amyloid drugs.

Although the review included data from these trials, much of the evidence the review relies on comes from older experimental drugs that were discontinued due to trials that failed to show ‘meaningful benefit’.

“This review is attempting to paint an entire class of drugs with the same brush even though we know different anti-amyloid treatments can act in different ways,” says Dr Susan Kohlhaas, Executive Director of Research and Partnerships at Alzheimer’s Research UK.

Despite the review’s claims, experts say these should not take away from the achievements of the latest Alzheimer’s drugs.

“Lecanemab and donanemab have shown us that slowing Alzheimer’s is possible, representing genuine progress,” says Prof Sir John Hardy, UCL Institute of Neurology and Vice President of Alzheimer’s Research UK. “They are not perfect, but they have opened the door to a new era of treatment.”

“What matters now is that research into treatments is moving rapidly, and the pipeline of potential therapies is more diverse and promising than at any point in my career.”

What does ‘clinically meaningful’ mean?

The review suggests that anti-amyloid treatments do not have a ‘clinically meaningful’ impact. However, there is no agreed definition on what ‘clinically meaningful’ means. And current clinical trial measures cannot always reflect what matters most to people with dementia.

“We regularly hear from families affected by dementia that even a delay of several months in decline could provide valuable, meaningful time with loved ones and that shouldn’t be minimised,” says Dr Kohlhaas.

What about the side effects of these drugs?

Although the review highlights the known risk of ARIA, which are changes to brain structure and swelling seen on MRI brain scans, the studies it looked at didn’t consistently report how often this led to symptoms or how those symptoms were managed.

The review itself doesn’t fill an important gap in our understanding of how safe these drugs are in a healthcare setting.

Read more about the side effects and the benefits of the drugs on our new treatments for Alzheimer’s pages.

What does the latest evidence say about anti-amyloid drugs?

Newer, longer-term evidence suggests that lecanemab and donanemab may deliver modest but sustained benefits beyond the 18-month limits of earlier studies, yet this emerging data is not reflected in the review.

That is why Alzheimer’s Research UK is clear that longer term evidence gathered from routine healthcare settings is needed, to understand how these treatments should be used in practice. Initiatives like ACCESS AD will be crucial to further our understanding, as this is designed to show how these medicines perform when offered through standard NHS pathways.

What does the future hold for treatments for Alzheimer’s?

“Anti-amyloid treatments will not be the whole answer to curing Alzheimer’s, and research is already moving towards a wider range of biological targets,” says Dr Kohlhaas. “But it’s not accurate to dismiss their impact as ‘trivial’, especially when the review’s analysis has clear constraints that limit what it can tell us.”

Importantly, the pipeline of new drugs being explored for Alzheimer’s disease is stronger than ever, with more potential treatments entering clinical trials in people. Nearly 140 experimental treatments are being tested in more than 180 trials across the globe.

Alzheimer’s Research UK’s Drug Discovery Alliance is playing a crucial role in expanding the range of drug targets. By connecting discoveries made in the lab with industry expertise, the Alliance aims to develop a set of different treatments to address the many biological changes that cause Alzheimer’s and other forms of dementia.

“For the first time, I can see a future where Alzheimer’s is treated with the same confidence and combination-based approach we use for other major diseases, like cancer.” says Prof Sir John Hardy.

“That gives me real hope, but we’ll only get there through research.”

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