Preparing for a world where Alzheimer's disease is treatable

Alzheimer's disease is the most common cause of dementia. Of the 944,000 people living with dementia in the UK, 60-80% have Alzheimer's. Currently, the only available drugs for Alzheimer's treat symptoms. However, recent clinical trials show that new therapies -- which use monoclonal antibodies to remove amyloid plaques that form on the brain -- may slow down disease progression. Two of these 'disease-modifying therapies' (DMTs) have been granted 'breakthrough therapy' designation in the UK and are likely to become available to patients by mid-2024 (pending regulatory approval).

In the UK, dementia care is mostly centred around psychiatry-led memory clinics in the community. In their current state, it is extremely unlikely that DMTs will be administered in these settings. Delivery of these new treatments will require a major restructure to existing dementia services -- from determining eligibility to delivery of the treatment itself, including follow-up. It will require additional staff and training across imaging, diagnostics and pathology, and other clinical services. It will also require access to laboratories that can carry out biomarker testing to confirm whether a patient is eligible for the treatment.

The potential roll-out of DMTs presents major challenges for services and has real potential to amplify existing inequities in service access. To anticipate and mitigate these challenges, researchers from Queen Mary's Centre for Preventive Neurology, UCL's Dementia Research Centre, and UCL Partners carried out essential research to estimate how many patients are likely to be eligible for DMTs.

The researchers compared clinical case notes from over 1,000 people attending either community memory clinics or specialist cognitive services in England. They found that 32% of those attending memory services and 14% of people attending specialist cognitive services would likely be referred for consideration for the new DMTs. Researchers found that amyloid biomarker tests were available for people attending specialist cognitive services in the form of specialist scans called PET scans and spinal fluid tests. However, fewer than 1% of people attending community memory clinics had undergone biomarker tests.

While a sizeable proportion of patients attending memory clinics may be referred for therapy for Alzheimer's disease, only a minority are likely to be suitable, once they have undergone biomarker testing. The researchers highlight an immediate need for biomarker testing to ensure that the right patients can be identified for these treatments.

First author, Professor Ruth Dobson, Professor of Neurology at Queen Mary University of London, Consultant Neurologist and Dementia Theme Co-Lead for UCL Partners, said: "The development of disease modifying therapies for dementia has the potential to drive significant service changes. We have seen the impact of this in MS and stroke. It is crucial to understand and plan such changes proactively in order to ensure best care for all people living with dementia, regardless of initial treatment availability and eligibility."

Study lead, Professor Rimona Weil, Consultant Neurologist at UCL and the National Hospital for Neurology and Neurosurgery, and Dementia Theme Co-Lead for UCL Partners said: "Working with clinicians running memory clinics was crucial to this work, meaning that we could get real-world estimates for how many people are likely to be referred for these new drugs for the first time."

Study co-lead, Professor Catherine Mummery, Consultant Neurologist at UCL and the National Hospital for Neurology and Neurosurgery, said: "We demonstrate that diagnostic resources affect the accuracy of diagnosis and referral habits, and that a collaborative networked approach is critical to developing a functioning treatment service in preparation for these new therapies."

David Thomas, Head of Policy and Public Affairs at Alzheimer's Research UK, said: "New Alzheimer's drugs are finally on the horizon, but for their full potential to be realised, health systems need to be able to offer people with symptoms of dementia an accurate and early diagnosis to find out whether these treatments could benefit them.

"As this research demonstrates, the NHS is a long way from being able to do this testing routinely. Whoever forms the next government must invest in the NHS urgently, to ensure we have the right diagnostics and workforce in place to help identify people who could benefit from new treatments should they be deemed safe and effective by the regulators. A key part of the solution is cheaper, more scalable diagnostics, such as blood tests, for use in clinical care."

This study was produced by researchers from a network of universities who form the Academic Health Science Centre for UCLPartners and in collaboration with a network of clinicians in memory clinics in London and the South East.