In a breakthrough, an antibody that can almost clear the visible signs of Alzheimer's disease from the brain has been discovered.
Researchers scanned the brains of people with the degenerative condition as they were given doses of the drug, which is based on an immune cell taken from the blood of elderly people aged up to 100 who showed no signs of the disease. After a year, all the toxic "amyloid plaques" that build up in patients disappeared from the brains of those given the highest doses of the antibody. The findings suggest the plaques are part of the cause of the disease - not simply a byproduct.
One of the researchers, professor Roger Nitsch of Zurich University described what they found when they scanned the brains of patients given either a placebo or three different doses of the antibody, called aducanumab. "One year later, the images of the placebo group were unchanged. In the antibody group, where patients were given 10mg of dose, reduction in amyloid plaques was visible - the higher the dose, the larger the degree of reduction," he said.
"Compared to other studies, the effect size of this drug is unprecedented."
Commenting on the research in journal Nature, professor Eric Reiman of Arizona University said, "Confirmation that an anti-amyloid plaque treatment slows cognitive decline would be a game-changer for how we treat and prevent Alzheimer's disease."
The study, led by scientists at pharmaceutical companies Biogen and Neurimmune, sparked major interest from experts. Dr Tara Spires-Jones, interim director of Edinburgh University's Centre for Cognitive and Neural Systems, said the research showed the antibody "robustly reduced amyloid pathology in a small group of people in very early stages of the disease". "But many drugs make it through this early stage of testing then go on to fail in larger trials," she said.
And Dr James Pickett, head of research at the Alzheimer's Society, said, "No existing treatments for Alzheimer's directly interfere with the disease process - and so a drug that slows the progress of the disease by clearing amyloid would be a significant step." He noted the researchers had found some side-effects, such as headaches, and the initial trial had not been designed to measure whether the drug slowed the decline in memory and thinking. Presently, larger trials are now under way, including in the UK, and due to finish in 2020.
However Gordon Wilcock, professor of geratology at Oxford, was downbeat about the findings. "We have had previous trials of anti-amyloid strategies, especially the monoclonal antibodies, that have failed to deliver at phase three." the independent