New research gives hope that a new drug, called Rember, could help slow the progression of Alzheimer's, by tackling the protein tangles that cause brain cell death.
Initial research suggests that Rember slows cognitive decline in people with Alzheimer's and could be more than twice as effective as current treatments.
The research findings are being presented at the International Conference on Alzheimer's Disease in Chicago.
Tau is a protein that helps brain cells keep their structure and communicate with each other. In people with dementia this protein becomes tangled and it causes brain cell death.
Studies in specially designed mice have shown that Rember reduces the tangles and improves cognition, but trials in humans have so far only suggested Rember slows cognitive decline.
Professor Clive Ballard, the director of research at the Alzheimer's Society, said: "This is a major new development in the fight against dementia. It is the first realistic evidence that a new drug can slow cognition decline in people with Alzheimer's, by targeting the protein tangles that cause brain cell death.
"This first modestly sized trial in humans is potentially exciting. It suggests the drug could be over twice as effective as any treatment that is currently available.
"However, we are not there yet. Larger scale trials are now needed to confirm the safety of this drug and establish how far it could benefit the thousands of people living with this devastating disease."