Alzheimer’s disease is on the rise, even as doctors continue to struggle to find potential treatments for it. Researchers expect the number of those suffering from dementia to grow from 44 million at present to three times that by 2050.
The growing number puts increased pressure on researchers to do something to ameliorate the disease. And one drug is attracting the spotlight as it enters clinical trials. Eric Karran, the director of research at Alzheimer’s Research UK, said in a press conference in the lead-up to a G8 summit on dementia that he is “full of hope” that a drug now being tested in the United States on patients with mild dementia may be to Alzheimer’s disease what statins are to heart disease.
The drug, called solanezumab, appears to slow the buildup of amyloid beta in the brain and improves cognitive function in patients with mild dementia when given as a monthly shot.
But the excitement about the drug is as much a measure of other treatments’ failures as it is of its success. Researchers don’t even know for sure that amyloid beta causes Alzheimer’s-related dementia, although it is clearly linked. And solanezumab has already been shown not to help those whose dementia is more than mild.
In a clinical trial on patients with mild and moderate dementia, the results first showed no cognitive improvements. It was only after researchers re-crunched the data, which included standard mental tests used on patients with dementia, that they found improvements in patients with mild dementia hiding in the overall results.
Other drugs that have showed promise in the lab have sometimes affected amyloid beta levels but have not produced even these small cognitive improvements in Alzheimer’s patients.
“The marginal benefits of solanezumab are encouraging to support continued evaluation in future studies, and offer small support in favor of the ongoing viability of the ‘amyloid cascade hypothesis,’” Harvard researchers tepidly concluded in a recent review of the literature on the drug.