Two much-hyped Alzheimer’s drugs may never get NHS approval after an official report claimed they have ‘limited clinical benefit’.

Senior health service figures also raised concerns that rolling out the treatments could cost the taxpayer £1 billion per year as well as endangering the lives of Alzheimer’s patients due to dangerous side effects that cause brain bleeds.

Studies last year appeared to suggest that the two drugs – lecanemab and donanemab – were capable of slowing the progress of the degenerative brain disease by as much as a third. 

However, despite making headlines around the world, independent analysis has since suggested the drugs could only slow the disease for less than a year.

Lecanemab has already been approved in the US, and UK health regulators are now considering permitting both treatments.

Studies last year appeared to suggest that the two drugs – lecanemab and donanemab – were capable of slowing the progress of the degenerative brain disease by as much as a third (stock image)

The Mail on Sunday has learned that senior NHS officials have their doubts about offering lecanemab and donanemab to British Alzheimer’s patients (stock image)

But The Mail on Sunday has learned that senior NHS officials have their doubts about offering lecanemab and donanemab to British Alzheimer’s patients.

An NHS report seen by this newspaper reveals that top dementia doctors have suggested the side effect-heavy medicines have only a ‘relatively modest’ benefit.

Experts are now calling on NHS regulators to reject the drugs, which they argue could take up a significant amount of NHS resources and endanger people’s lives.

There are some one million Alzheimer’s sufferers in the UK and there are currently no treatments capable of slowing the disease.

But last year lecanemab became the first drug that seemed to give sufferers hope.

The £20,000-a-year treatment works by attacking a toxic protein in the brain called amyloid which is linked to dementia symptoms.

Several months later, donanemab, which also targets amyloid, was shown to be similarly effective.

An NHS report seen by this newspaper reveals that top dementia doctors have suggested the side effect-heavy medicines have only a ‘relatively modest’ benefit

But experts have noted that the drugs appear to be most effective for patients with the very earliest form of Alzheimer’s – and since there is no effective test for the disease, barely any NHS patients are diagnosed at this stage. 

The drugs also appeared to buy them just nine extra months of good health.

Data shows that about one in ten participants experienced swelling in the brain and one in six had brain bleeds. Three patients out of 1,800 on a lecanemab trial died of suspected side effects, too.

In an NHS report exploring the preparation needed to roll-out the drugs, officials warned that offering them would cost between £500 million and £1 billion a year.

‘It would be better to sit on our hands and do nothing than spend a billion pounds on a drug which might not even work,’ says Prof Peter Morgan, a dementia expert at Cardiff University. 

‘There’s a good chance these treatments never get rolled out on the NHS.’