A CLINICAL trial of a once-promising Alzheimer's drug has been stopped.
An independent panel of experts reviewing pharmaceutical company Merck & Co's trial into Verubecestat suggested its discontinuation after it deemed there was "virtually no chance of finding a positive clinical effect".
It was initially hoped the drug would help patients with mild to moderate forms of Alzheimer's disease by targeting and blocking amyloid, a substance in the brain widely believed to cause the condition.
Alzheimer's expert Bryce Vissel, the director of the Centre for Neuroscience and Regenerative Medicine at Sydney's University of Technology, said there were lots of different reasons the drug may have failed, though a definitive answer was still not clear.
"The results of this trial were highly anticipated, not only because of hope for people with dementia, but also because, if the drug had succeeded, it would have demonstrated that beta amyloid contributes to the cause of Alzheimer's disease, a major but controversial theory in the field," Professor Vissel said.
"This is disappointing news for families who are watching Alzheimer's rob their loved ones of their memories and emotions - it consumes and absorbs families."
The news comes after Alzheimer's Australia released findings showing the multibillion-dollar cost of dementia has on Australia is rising.
"We must continue to pursue this disease," Professor Vissel said.
"There's good reason to have hope and optimism that with the pursuit of excellent science and some rethinking about this disease, a treatment will become available for this devastating disease in our lifetimes."
It's the latest promising Alzheimer's drug to have failed the clinical trial, with company Eli Lilly & Co announcing its own failure of a different drug targeting amyloid three months ago.
