REVOLUTIONARY dementia drugs could actually shrink patients’ brains and be harmful, warn scientists as UK health chiefs prepare to rule on NHS use.
The Medicines and Healthcare products Regulatory Agency (MHRA) could decide on approval as soon as next week.
GettyDementia drugs lecanemab and donanemab could actually shrink patients’ brains and be harmful, scientists warn[/caption]
Experts say approval and NHS rollout is still in doubt because of fears about serious side effects.
Manufacturers claim the drugs, lecanemab and donanemab, can slow the progress of Alzheimer’s disease by around a third by clearing toxic proteins out of the brain.
But top scientists say there is no proof they reduce symptoms and people who take them face a much higher risk of the brain bleeding, swelling or shrinking.
The Food and Drug Administration in America approved lecanemab last year but issued a “black box warning” because of the dangers – its strongest possible caution to doctors.
Figures suggest half a dozen patients died in the clinical trials, up to one in 100 experienced serious side effects and a third had bleeding on the brain.
Dr Madhav Thambisetty, from the US National Institutes of Health, said: “These drugs carry serious risk of harm or death.
“The most common side effects are brain swelling and brain bleeding, and loss of brain tissue has been consistently seen in these trials.
“I don’t think you need to be a neurologist to say that brain loss, bleeding or swelling is bad for somebody.”
More than 600,000 people in the UK have Alzheimer’s disease, the number one cause of dementia, and it has no cure.
Around two in 10 over-65s have mild cognitive impairment, which is age-related brain damage that raises the risk of dementia.
I would not want to give this to one of my patients or to a member of my family who had Alzheimer’s disease
Dr Rob Howard
The new drugs must be given as early as possible before brain cells are killed off – but not everyone with early signs of Alzheimer’s will develop it.
Dr Rob Howard, a dementia expert at University College London, said: “The benefits of these drugs are too small to be noticeable by the patient or by their doctor.
“The treatment has to be given really early so I’m worried about the risks of people being misdiagnosed and being given a treatment that can’t help them and can hurt them.
“I would not want to give this to one of my patients or to a member of my family who had Alzheimer’s disease.”
Fears about the small benefits and deadly side effects mean the MHRA’s decision is not a done deal.
David Thomas, head of policy at Alzheimer’s Research UK, said: “People affected by dementia have waited too long for new treatments.
“There is now a chance to change that but lecanemab and donanemab have relatively modest effects and come with risks of serious side effects that need to be fully scrutinised.
“There are no assurances that lecanemab will be approved in the UK just because it has been in the US and parts of Asia.”
Lecanemab manufacturer Eisai said: “Brain volume loss was not associated with worsening in measured neurodegenerative outcomes.
“Clinical measures indicated a benefit from treatment and not a detriment.”
Eli Lilly, which makes donanemab, said: “It will be important for doctors and patients to discuss the benefits and risks of these medicines before treatment if they are authorised.”
The difference between Alzheimer’s and dementia
Dementia is a general umbrella term used to describe the deterioration of a person’s mental ability.
It is a group of symptoms, such as memory loss, confusion, problems with language and understanding, and behaviour changes.
There are many different types of the debilitating condition, and Alzheimer’s is the most common.
It accounts for 60 to 80 per cent of dementia cases, which is why the names may sometimes be used interchangeably.
An estimated 944,000 people in the UK have dementia. This is projected to rise to 1.6million by 2040.
Source: Alzheimer’s Society and NHS