A new drug is making headlines around the world for becoming the first-ever drug to slow the progression of Alzheimer’s disease.
After an 18-month trial of 1,800 patients, lecanemab Slows down the patient’s mental decline by 27%.
While scientists are hailing a “new era” of treatment, the pressure on the NHS and the scale and complexity of the disease mean it could be a long time before patients and their families really benefit in the UK.
What is Alzheimer’s disease – how is it different from dementia?
Alzheimer’s disease is the most common dementia.
Dementia is an umbrella term for a group of conditions that cause brain decline and lead to memory loss, confusion and difficulty performing everyday tasks.
Other types of dementia include vascular dementia, mixed dementia, dementia with Lewy bodies, and frontotemporal dementia.
Alzheimer’s disease causes proteins to build up in the brain and form abnormal structures sometimes called “plaques” or “tangles,” which kill nerve cells and brain tissue.
It also makes it harder for chemical signals to pass between brain cells.
All forms of dementia are progressive and get worse over time.
Every patient’s disease trajectory is different, and some will decline faster than others.
There are generally three stages—early or mild, moderate or intermediate, and severe or late.
Symptoms of Alzheimer’s disease include:
- memory loss
- decreased mental acuity
- Difficulty remembering words or speaking
- Problems with movement, including eating, drinking, and walking
- behavior or personality changes
Alzheimer’s disease limits life in two ways.
Research suggests it may be strongly linked to other physical health conditions such as cardiovascular disease and diabetes.
But in later stages of dementia, a person’s immune system is weakened and they are likely to be unable to swallow or use the toilet independently.
This increases the risk of infection and other conditions that can lead to death.
Life expectancy depends on when a person is diagnosed – but is about 8 to 10 years, longer than other forms of dementia.
How common is it?
More than 850,000 people in the UK live with dementia, but this number is expected to exceed 1 million by 2025 as more and more people live longer.
Most of them – 520,000 – have dementia.
One in 14 people over the age of 65 has dementia, and this number increases to one in six people over the age of 80.
According to the latest Dementia UK report in 2014, it costs the UK £26.3bn a year – more than cancer, heart disease and stroke.
While the NHS pays £4.3bn of this – the social care sector pays more – £10.3bn.
This is because most dementia is managed in the community and nursing homes, not in hospitals.
Hospitals are usually only involved in diagnosing conditions and caring for patients admitted for other or related medical problems.
Two-thirds of the total annual cost of £26bn is paid by patients, their families and carers.
According to Paul Edwards, Director of Dementia UK Clinical Services: “The NHS is already struggling to provide care for the growing number of people living with dementia, partly because of a lack of post-diagnosis and community support.”
His charity is calling on the government to deliver on a pledge it made in May to develop a 10-year dementia strategy.
Is there a cure now?
Unlike some other types of dementia, people with mild or moderate Alzheimer’s require medication.
Patients in early or intermediate stages can take donepezil, rivastigmine, or galantamine, all of which work by boosting chemical messengers in the brain.
They may also help reduce anxiety, which is often experienced by people with dementia as they experience cognitive decline.
People with moderate or severe Alzheimer’s are given a drug called memantine, which also boosts chemical messengers but also reduces challenging behavior changes and delusions.
There is no cure for dementia, so all drug treatments currently available only work for a limited time and do not slow the progression of the disease, only the symptoms.
Why is lecanemab different?
As Dr Susan Kohlaas, research director at Alzheimer’s Research UK, explains: “This is the first time a drug has been shown in a clinical trial to both reduce brain disease and slow memory decline.
“While the benefit is small and the side effects are significant, it marks the arrival of treatments that could slow the course of Alzheimer’s disease.”
So while current treatments only reduce symptoms, lecanemab can reduce amyloid in patients’ brains, which kills nerve cells and tissue.
In fact, the study showed that over the course of 18 months, the drug delayed the time to worsening in patients by 5 months.
Other pharmaceutical companies and trials can build on this to give patients, their caregivers and loved ones more time to live with better quality of life and fewer symptoms.
Will it be available on the NHS?
There are significant barriers to using lecanemab on the NHS.
That’s because it’s only available for people in the early stages of Alzheimer’s, and current pressure on health services means one in six people wait more than a year to see a specialist after being referred by a GP .
At that stage – it is too late for most patients to benefit.
And because the drug works by reducing amyloid, they must be detected by brain scans before it can be prescribed.
According to the Alzheimer’s Association, one in 10 people waits more than six months for a brain scan, again reducing the window in which lecanemab is available.
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The brain scans that the NHS uses to help diagnose dementia are usually MRI or CAT scans as well.
They can only eliminate other possible conditions, such as tumors — or show brain shrinkage and changes in blood vessels — rather than protein buildup.
A small percentage of patients are then sent for PET scans, which do show amyloids — but they’re not widespread.
Third, many people with dementia are diagnosed with “unknown dementia” – in 2021, the proportion will be 6.6% of people over 65 years old, and 17.2% of people under 65 years of age.
That means they can’t be given lecanemab because it’s only effective for Alzheimer’s.
What do I have to do?
Increased access to PET scans and blood tests in the NHS, which could also help with Alzheimer’s diagnoses, is key, dementia charities and research bodies say.
Dr Richard Oakley, deputy director of research for the Alzheimer’s Association, said: “More than ever, this highlights the need to prioritize early diagnosis, through wider use of PET brain scans and research to convert blood tests to Bring it into the clinic so people can access these when the drug becomes available.”
His colleague, Fiona Carragher, director of research and impact, also stressed the importance of early diagnosis.
“We may see a situation where people are on the waiting list for so long that their disease progresses too far to receive a potentially life-changing drug,” she said.
“We urgently need to focus on better ways to quickly and accurately diagnose people in their early stages.”