A ONCE-A-DAY pill that scientists hope could stop Alzheimer's disease in its tracks is due to go on trial.
A small number of patients with mild-to-moderate Alzhei-mer's could get access to the drug, known only as MK-8931, when the trial starts in the new year.
Should it prove effective, hundreds of thousands of sufferers in this country could potentially benefit from it in just a few years, experts have suggested.
Early tests indicate that the drug could be remarkably effective at halting the biochemical process, known as the amyloid cascade, that causes the disease.
Alzheimer's results from brain cells dying off, linked to the build-up of structures between cells called amyloid plaques.
Pharmaceutical firms have had some success with drugs that clear these plaques. One, called solanezumab, has been shown to slow mental decline in people with a mild-to-moderate stage of the disease by a third.
However, results were less positive than hoped, and researchers are increasingly convinced that the best way to attack Alzheimer's is before the plaques form in large numbers.
They are looking at agents which tackle the key ingredient of the plaques, a protein called beta amyloid.
In a pilot study of 200 healthy volunteers, the drugs company MSD showed that MK-8931 reduced levels of beta amyloid in spinal fluid by 92pc. Results were presented to the American Academy of Neurology earlier in the year.
MSD is rolling out the study to 1,700 people with mild-to-moderate Alzheimer's worldwide. Half will be given the drug and half a placebo, and researchers will measure rates of cognitive decline.
Dr Richard Perry, a consultant neurologist at Imperial College Healthcare NHS Trust in London, said: "It's about getting in early, so that if less amyloid is produced, less plaques will come together.
"From what I have seen, this drug looks encouraging in terms of reducing the level of abnormal beta-amyloid."
The researchers are not expecting the pill to improve the abilities of sufferers. Most experts think there is no way of reversing Alzheimer's damage. (© Daily Telegraph, London)