Scientists trialling a new treatment, called LMTX, slowed the progression of the disease over 15 months.
When the drug was the only treatment that patients took, it had a beneficial effect on key measures of Alzheimer’s — such as memory — for those with mild or moderate forms of the disease.
In the small trial, the 136 patients took the drug, leuco-methylthioninium-bis (hydromethanesulfonate), as a pill twice a day.
However, in a bigger trial, patients taking other drugs, alongside LMTX, did not have the same benefit.
The Alzheimer’s Society of Ireland (ASI) has described the progress as “heartening”.
Despite the lack of benefit in the larger trial, the ASI claimed it was still a positive step forward.
Emer Begley, policy manager with the ASI, said that “while, in this instance, the larger clinical trial didn’t meet its goal, the drug did show some benefits to a small subset of the study’s sample”.
Ms Begley said the results “should give us hope that the development of drug therapies to treat dementia are possible.”
The results of the study were announced at the Alzheimer’s Association International Conference in Toronto.
Serge Gauthier, from McGill University, in Canada, claimed the developments were incredibly encouraging for the future.
“Where there has been no practical therapeutic advance for over a decade, I am excited about the promise of LMTX as a potential new treatment option for patients,” he said.
It is unclear why the LMTX treatment only worked when it was the sole drug that patients took, or why its results failed to apply to the larger sample. Future research into questions raised by the trial need to be “explored further”, according to David Reynolds, of Alzheimer’s Research UK.
But the results of the small sample were still the “silver lining” of the study, said Mr Reynolds, chief scientific officer at Alzheimer’s Research UK.
Mr Reynolds said the discovery “marks an important step in the evolution of Alzheimer’s clinical trials”.
He said the “positive findings will need to be confirmed” in a second, ongoing trial, before they can assess if the LMTX treatment will be better for dementia patients than existing drugs.
Ms Begley said the initial finding is an example of the benefits of increasing funding. She said that “recent, large-scale investment into dementia research is starting to bear fruit, which is creating a greater potential for positive outcomes to emerge, for people with dementia, into the future”.
In Ireland, 48,000 people have dementia. The majority of patients are older, but 4,000 of these are under 65 and have what is called early onset dementia.
The ASI estimate that the number of people with dementia is set to rise substantially in Ireland. They state that by 2046 more than 150,000 people will have the disease, due to an ageing population.
Mr Gauthier said that, “as a practising clinician, I see Alzheimer’s patients, their families and care-givers, every day, and continually share their desperate need for a truly therapeutic product.
“This is the first time it has happened, in our field, that a drug reduced the rate of brain atrophy.”
Alzheimer’s Society of Ireland national helpline is 1800 341 341, or www.alzheimer.ie