Researchers at three pharmaceutical companies are reporting results of new drugs that show promise for slowing the rate of cognitive decline in patients with early stage Alzheimer's disease.
The three companies – Eli Lilly, Roche and Biogen – have all been developing drugs based on genetically engineered monoclonal antibodies to mimic the actions of the immune system and target the buildup in the brain of beta amyloid, an abnormal form of protein that builds up as plaque and can destroy brain cells.
Researchers at Eli Lilly say their drug, solanezumab, can attack the sticky plaque buildups.
The drug has long been considered a potential dementia treatment, but a trial ending in 2012 seemed to suggest it failed to improve the outcome for Alzheimer's sufferers.
However, a closer analysis of the data suggests it may have been effective in patients who were in the earliest stages of the disease, company researchers told attendees at the Alzheimer's Association International Conference 2015 in Washington.
In those patients, solanezumab appeared to slow the progression of cognitive decline by about 34 percent, they said.
"It's another piece of evidence that solanezumab does have an effect on the underlying disease pathology," says Dr. Eric Siemers of the Lilly Research Laboratories. "We think there is a chance that solanezumab will be the first disease-modifying medication to be available."
Although the drug did not stop the progression of the disease, only slowed it, Alzheimer's experts said it represented a step forward.
"Think about a disease that has a 10-year span. We're talking about delaying progression to [a nursing home] or to loss of ability to communicate with family," says Paul Aisen, director of the University of Southern California's Alzheimer's Therapeutic Research Institute.
Two similar drugs that also target the accumulation in the brain of the protein known as beta amyloid, are also in development; aducanumab, from Biogen, and gantenerumab from Roche.
The race to develop effective Alzheimer's treatments becomes ever more pressing as the baby boomer generation moves into old age, experts say.
By the middle of the century – when that generation will be between 75 to 95 years old – it is predicted 13.5 million people in the U.S. will be suffering from Alzheimer's.
Dealing with the disease is expected to account for a quarter of all Medicare spending each year, around $325 million.
As encouraging as the recent announcement might be, experts cautioned patients and their families that progress would likely continue to be slow and incremental.
"To be honest, these results are not going to be something they can get next week," says physician David Knopman, vice chairman of the Alzheimer's Association medical and scientific advisory council.
