Here we set out some of latest thinking on the diseases of the brain and nervous system that lead
to dementia.
Much of this thought and the practical research it inspires may lead nowhere: theories are literally
tested to destruction. Not all research is equally rigorous and the many well-designed trials can
fail. Sometimes there are breakthroughs that promise real advances in treatment and management
of disease but these can take many years to become widely available and, over time, found to be
more or less effective than expected. So please treat all that you read here with caution, but not
without hope..
Lacanemab: the big news
When this new Alzheimer’s medication was licensed for use in the UK this summer, what really
attracted the headlines was the sheer cost of it.
Best cost estimates were around £20,000 a year for the drug and a further £20,000 a year in
monitoring and administration of it. In fact it is so expensive that NICE (National Institute for
Health and Care Excellence) decided it was too expensive for use by the NHS.
The possibility of serious side effects is the reason for the high cost of administering it – by
infusion -and monitoring patients closely for possible adverse reactions. On top of this, trials
suggest the drug, trade name Leqembi, is effective only for up to a year and only for those in the
earliest stages of Alzheimer’s.
But all this tends to obscure the real news: that for the first time we have a drug that actually
treats the disease, not just the symptoms of it. It is the first real breakthrough in decades.
Lacanemab is a monoclonal antibody, a laboratory produced protein that binds to and attacks the
amyloid plaques in the brains of Alzheimer’s patients which is thought to cause their
dementia.This monoclonal antibody (MAB) recognises the amyloid (another form of protein) and
works with the brain’s immune cells to clear the build-up of this material which is thought to be
toxic to brain cells.
MABs are already used in the diagnosis and treatment of other diseases, including some cancers,
often to carry drugs or toxins directly to cancer cells. Anti-amyloid MABs are the first AD therapies
that can actually slow down the disease by interfering with the basic biological processes of it.
The fact that this therapy works at all supports the view that it is the build up of amyloid that is a
root cause of AD and it therefore clears the way for further development of amyloid targeting
therapies and new therapies for other neurodegenerative diseases.
Donanemab “poor value”
The latest new treatment for early stage Alzheimer’s Disease, donanemab, has been licensed for
use in the UK, but rejected as too costly for NHS use.
Donanemab, is similar in its action to lacanemab, which has already suffered the same fate. The
National Institute for Health and Care Excellence (NICE) has judged it poor value for money at a
similar price to lacanemab and effective for less than a year.
The Alzheimer’s Society’s Chief Policy and Research Officer, Professor Fiona Carragher said: “In
other diseases, like cancer, treatments have become more effective,safer and cheaper over time
and we hope to see similar progress in dementia.”
Dementia is ‘highly preventable’
The Lancet Commission on dementia, which in 2020 identified 12 risk factors for the development
of dementia has now identified two more.
Factors identified in 2020 were:
- Low educational achievement
- Hearing loss
- Hypertension
- Smoking
- Obesity
- Depression
- Physical inactivity
- Diabetes
- Excessive alcohol consumption
- Traumatic brain injury
- Air pollution
- Social isolation
To these we can now add:
- Untreated loss of vision
- High LDL cholesterol
There is now compelling evidence for all these factors according to The Lancet Commission’s
2024 update based on further meta analysis of research studies.And it is really good news, says
the commission, in that all these factors can be either minimised or eliminated, offering new hope
of prevention and care.
In their update, the Lancet Commission says: “As people live longer, the number of people who
live with dementia continues to rise, even as the age-specific incidence decreases in high-income
countries, emphasising the need to identify and implement prevention approaches.
“We have summarised the new research since the 2020 report of the Lancet Commission on
dementia, prioritising systematic reviews and meta-analyses and triangulating findings from
different studies showing how cognitive and physical reserves develop across the life course and
how reducing vascular damage (eg, by reducing smoking and treating high blood pressure) is
likely to have contributed to a reduction in age-related dementia incidence.
“Evidence is increasing and is now stronger than before that tackling the many risk factors for
dementia that we modelled previously… reduces the risk of developing dementia. In this report,
we add the new compelling evidence that untreated vision loss and high LDL cholesterol are risk
factors for dementia”.
Read more here:
https://www.thelancet.com/commissions/dementia-prevention-intervention-care
Quick and easy dementia tests?
A blood test for early stage Alzheimer’s Disease and similar brain diseases could be available to
the NHS within five years.
UK-wide trials are being conducted by teams of researchers to develop blood tests that will boost
early diagnosis of all the diseases that lead to dementia. One team, from University College
London, and another from Dementias Platform UK, University of Oxford, will be carrying out the
clinical trials.
Reliably accurate blood tests will complement the development of a new generation of drugs, like
lacanemab and donanemab, that are most effective at treating early stage disease. At present it
can take years for a formal diagnosis to be made and, even then, it may not be fully accurate.
NHS England reports that only 2% of people who receive a dementia diagnosis have actually
undergone tests such as PET scans and lumbar punctures that produce the most reliable
diagnosis at an early stage.
According to NHS England 478,822 people had a recorded dementia diagnosis in February 2024,
an increase of 1,199 since the previous month.
The research teams will start recruiting trials participants soon. Although blood tests have been
developed for AD and other dementia-causing diseases that show very promising results, none
has yet been tested in ‘real life’ situations.
The two research teams will take different approaches. The Oxford based READOUT study will
test both existing and new blood tests for a range of types of dementia and test whether or not
the test can identify the diseases at different stages. The second study, ADAPT, based at
University College London, will focus on the most promising test for Alzheimer’s disease, which
measures levels of a protein called p-tau217. This increases in the blood as other proteins build
up in the brain during the development of Alzheimer’s disease. The researchers will carry out a
clinical trial to see whether measuring p-tau217 in the blood increases the rate of diagnosis for
AD.
The two-pronged approach to the research is designed to boost the chance of providing enough
evidence to validate the use of blood tests in the NHS.
If you’re interested in taking part in this research, please visit Dementias Platform UK’s
website, or get in touch with our Information Services team on
infoline@alzheimersresearchuk.org or 0300 111 5 111.