31-07-2025
Alzheimer's wonder drug delays disease for four years
Alzheimer's patients can stave off the progression of disease for four years with radical new treatments, The Telegraph can reveal.
Trial findings show that some patients – who were given the drug lecanemab at an early stage and had little 'pathological' change to the brain – even saw improvements in their cognitive scores.
The drug was licensed for use in the UK last year after trials found it was the first medication to slow progression of disease. Over 18 months, it was found to have slowed it by 5.7 months.
The new findings, from a trial of 478 patients who stayed on the drug for four years, found an average delay of almost 11 months before their disease progressed to the next stage.
Remarkable results were seen in a sub-group of patients who had low levels of tau, the protein that accumulates as Alzheimer's progresses. In total, 69 per cent of those in this group had no decline at all over four years, and 56 per cent saw an improvement in their cognitive scores.
Prof Christopher Van Dyck, the director of the Alzheimer's Research unit at the Yale school of medicine and the study leader, said: 'The thing I really focus on is the time saved. You will get worse over time, but it will take longer to get there.'
He said the findings, presented for manufacturers Eisai, made the case for starting early in treatment of Alzheimer's as 'people with the lowest pathology do tend to do the best'.
Experts said the results – presented at the Alzheimer's Association International Conference in Toronto – offered hope that the new class of medicines could 'meaningfully change the course of the disease', not just slow decline in the short-term.
They also said there was growing evidence to support earlier prescribing of such drugs, with trials planned shortly to see if similar medications, which appear to have fewer side effects, could one day be used preventively.
About one million people in the UK suffer from dementia, with Alzheimer's disease the most common form.
Lecanemab is part of a new class of medicines aimed at clearing amyloid plaques, the hallmark of Alzheimer's.
Typically, patients with mild dementia see scores rise by between one and two points a year on scoring systems used to track the disease. But across the whole trial group, decline was measured at an increase of just 1.75 points over four years.
Results from a separate trial of donanemab, a similar drug, also showed powerful results.
The drug is normally given for 18 months, or until amyloid in the brain is cleared. Scientists tracked patients for a total of three years, including the time off the drug.
The changes in dementia scores, compared with untreated patients, suggest that those prescribed donenamab had gained between six and 12 months before disease progressed.
Dr Sheona Scales, the director of research at Alzheimer's Research UK said: 'These latest findings offer renewed hope that Alzheimer's treatments can meaningfully change the course of the disease, not just slow decline in the short term.
'New long-term data show that the benefits of donanemab may continue even after treatment ends, and people on lecanemab for up to four years maintained cognitive gains, with some even improving. Among those treated early with lecanemab and with low levels of tau, over half showed no decline after four years.
'This is the first wave of disease-modifying treatments for Alzheimer's and, while the progress is encouraging, there are still many pieces of the puzzle we don't yet have.'
Dr Scales said studies were helping to address key questions about long-term benefits, but uncertainties remained over what happens in the brain when treatment stops and whether amyloid levels stay low long-term.
'As the evidence grows, it's vital that in the UK we continue to evaluate the potential benefit that the treatments could offer to people with Alzheimer's,' she added.
Results from another trial earlier this week suggest that a third treatment called trontinemab, which works in a similar way, but is engineered to reduce side effects, could be the most powerful weapon yet against dementia.
The study presented earlier this week found the treatment can clear the devastating plaques associated with Alzheimer's far more rapidly than any current licensed drug.
The lack of side effects means it could be offered to large populations. This also means it could be offered at a far lower price than current medications, which require intense monitoring – including regular scans – meaning it is more likely to be funded by the NHS.
