“This result confirms that we are now entering the treatment era of Alzheimer’s disease,” said Dr Cath Mummery, consultant neurologist at University College London Hospitals NHS Foundation Trust.
“The decades-long battle to find treatments that change Alzheimer’s disease is changing.
“We are now entering the time of disease modification, where we might realistically hope to treat and maintain someone with Alzheimer’s disease, with long-term disease management, rather than palliative and supportive care.”
Trial results ‘dispel doubts’
Current drugs for dementia work by boosting chemical signals in the brain or treating symptoms such as insomnia or depression, but cannot stop the progression.
Use on the NHS is likely to be a long way off as the new treatment, which is administered once a month by infusion, would first need to be approved for safety by the Medicines Healthcare and Products Regulatory Agency (MHRA).
The National Institute for Health and Care Excellence (Nice) would also need to approve it for cost-effectiveness. The process of these approvals can take years.
There are 944,000 people living with dementia in Britain, most suffering from Alzheimer’s.
The number is expected to increase to more than one million by 2030, with one in three people born in the UK this year expected to develop dementia in their lifetime.
The condition costs the country £34.7 billion ($70.18b) annually and is now the leading cause of death.
It is the second Alzheimer’s drug to prove successful in the past year after Eisai/Biogen’s lecanemab was shown to slow decline by 27 per cent.
Donanemab works by clearing the brain of sticky amyloid plaques that prevent brain cells from communicating.
In recent years, scientists have doubted whether removing amyloid was the correct strategy, after the failure of several trials of drugs to break up the plaques.
John Hardy, professor of neuroscience at University College London (UCL) said the trial results should “dispel any lingering doubts” that the way to treat Alzheimer’s was to remove amyloid from the brain.
The new study involved 1182 patients with early Alzheimer’s disease, including mild cognitive impairment, who were given monthly infusions of donanemab.
As well as postponing a worsening of clinical symptoms, the drug also allowed patients to continue to perform daily activities for longer, such as shopping, housekeeping, managing their finances and taking medication.
The study also enrolled 552 people who were at a later stage of Alzheimer’s. Results showed the drug slowed down disease progression by up to 29 per cent.
However, researchers warned that the drugs had troubling side effects, such as brain swelling and bleeding. One in four trial participants suffered swelling or bleeding, and three people died from the side effects.
Eli Lilly said it would apply to the US Food and Drug Administration (FDA) for approval this quarter and “will proceed with global regulatory submissions as quickly as possible”.
British experts called on the UK regulators to quickly licence the new therapies and said the NHS should get ready to administer the treatments.
Lecanemab received FDA approval in January but has yet to be granted MHRA approval.
Dr Richard Oakley, associate director of research at the Alzheimer’s Society, said: “We need decisions as quickly as possible from the regulators MHRA and Nice.
“But that’s not the end of the story - we can’t end up in a situation where there are new drugs being approved but people can’t get access to them early in their dementia journey when they work best.
“We need more accurate, earlier dementia diagnosis in the NHS.”
Dementia experts also warned that services were already struggling to diagnose patients and could not shoulder the burden of sophisticated new therapies.
Dr Tom Russ, director of the Alzheimer Scotland Dementia Research Centre at the University of Edinburgh, added: “While this is another encouraging development, the UK NHS is not ready to implement an infusion-based therapy such as donanemab or lecanemab should they become licensed treatments in the UK.
“There needs to be significant support for struggling dementia assessment services, which are still emerging from the Covid-19 pandemic to continue to diagnose, treat and support people currently presenting while developing new ways to implement the disease-modifying treatments of the near future.”
Six warnings signs of possible dementia
· Constantly forgetting things you were told recently and asking the same questions repeatedly.
· Putting objects in unusual places – like your keys in the bathroom cabinet
· Frequent problems finding the right word, using substitute words (“that thing you sit on”), jumbling sentence structures, or, if English is your second language, going back to the language you spoke as a child.
· Getting lost in a familiar place or somewhere easy to navigate such as a supermarket.
· Having difficulty making sense of what you see – for example, judging distances on stairs, or mistaking patterns or reflections for other objects.
· Regularly being unable to follow what someone is saying and finding it hard to take part in conversations.
