The latest influential report has found that “breakthrough” drugs to treat Alzheimer’s are unlikely to help sufferers.

The scientists claimed the effect was “well below” what was required to have an impact on dementia sufferers.

But their report has also drawn a vitriolic attack from equally prestigious scientists who say it is flawed.

The drugs have been approved worldwide. However, they’re not reimbursed by the UK’s National Health Service, and it would cost you a whopping £90,000 to pay for 18 months of drug treatment and medical care. They would be too expensive for most, so even if they could afford it, should you buy it?

The drugs target a slime-like substance – called beta amyloid – that accumulates between the cells of the brain in Alzheimer’s disease.

Falling short

Scientists have developed antibodies – akin to the ones we produce to fight viruses and bacteria – to recognise the amyloid and remove it from the brain.

This strategy had been unsuccessful for many years, but recent studies with two new drugs – donanemab and lecanemab – demonstrated that they slow the rate of decline.

This was significant as it was the first drug to slow down the damage to the brain in Alzheimer’s disease.

The Cochrane Collaboration, which critically reviews medical evidence, examined 17 studies, involving 20,342 volunteers, of drugs to clear amyloid from the brain.

In general, they found the approach slows Alzheimer’s disease, but not enough to have a significant effect on patients.

But the drugs also had a chance of causing brain swelling and bleeding. The medicines also have to be administered every two to four weeks, and are expensive.

One of the authors of the report, Prof Edo Richard, a professor of neurology at Radboud University Medical Centre in the Netherlands, has patients with dementia.

“I’d tell my patients,” I asked him.

He said, “I would say, I think you are probably not going to benefit from the drugs, and they are a burden for you and your family.

“I think it’s very important that we are very clear to patients what they can expect. I’m always mindful not to raise people’s hopes.”

Now other ways of treating Alzheimer’s disease – such as reducing inflammation in the brain – needed to be pursued, he said.

The report’s conclusions have been supported by long-time critics of the drugs.

Prof Robert Howard, from University College London (UCL), said it was “unfortunate and unfair” to families of dementia sufferers that the drugs have been promoted in a way that is “not supported by robust science and that will have raised false hopes”.

David Essam, 81, from Kent, UK, participated in the international drug trials of one of the drugs, lecanemab.

Alzheimer’s forced him to retire from being a joiner – he forgot how to make a cabinet or use tools.

Cheryl said she still believes the drug helped her husband: “Maybe I’m naive, but I do feel he has gone on.”

Today’s results were “disheartening for everyone”, she said, but she believes the drug “gave him more time and gave me more time with David”.

But there is intense debate about how the analysis has been carried out.

The researchers say the drugs they analysed all clear amyloid from the brain, so the analysis shows whether that strategy works.

But others argue the drugs vary in how they work, and it’s not fair to lump the older experimental drugs with newer drugs that have been shown to be effective.

Prof Bart De Strooper, UK Dementia Research Institute, UCL, said the review “does not clarify the evidence, it blurs it” and “the flaw in this review is fundamental”.

“There were many early studies that failed, but the newer antibodies have shown small but significant clinical effects,” he said.

Dr Richard Oakley from the Alzheimer’s Society said: “It’s crucial that we read this review with a balanced view, and not use a sledgehammer to smash through decades of groundbreaking research.”

In the UK, these drugs can only be obtained privately, and therefore are beyond the reach of most.

In the past, the National Institute for Health and Care Excellence (which advises the NHS about the drugs it will fund) has not recommended them, but is again considering the evidence, taking into account the impact on unpaid carers.