Trials have shown that a new Alzheimer’s drug successfully targets one of the main signs of the disease in the brain, by halting the production of toxic amyloid proteins that cause the plaques found in the brains of Alzheimer’s patients. Following major clinical trials to be conducted next year, which will assess whether or not the drug slows mental decline in Alzheimer’s patients, it may become the first treatment to be approved for Alzheimer’s in over a decade.
The tablet is produced by the pharmaceutical company Merck.
UCL neuroscientist Professor John Hardy, who was among the first scientists to propose that amyloid proteins play an important role in Alzheimer’s disease, praised the results of the trials, saying “People are excited. This is a very nice drug and I’m sure Merck are feeling very pleased with themselves.”
Lead researcher in Merck’s trial, Matt Kennedy, put the results in context, saying “Today there are very limited therapeutic options available for people with Alzheimer’s disease, and those that exist provide only short-term improvement to the cognitive and functional symptoms. They do not directly target the underlying disease processes. There is an urgent need for [these drugs].”
In Alzheimer’s cases, the enzyme BACE1 breaks longer proteins into amyloid beta pieces, which themselves form sticky plaques in the brain. The new drug, a BACE1 inhibitor stops the production of the enzyme, in order to prevent plaques from forming. One leady theory on the process of Alzheimer’s is that accumulated proteins kill neurons, causing memory loss, cognitive decline, and other changes associated with Alzheimer’s.
As to when the drug might hit markets if next year’s trials are successful, Kennedy explained, “We are eagerly awaiting the results of the phase three clinical trials. It is premature to speculate on availability.”
The recent trial was published in the journal Science Translational Medicine on Wednesday. In the trial, 32 patients with early stage Alzheimer’s were given the drug, which is called verubecestat, every day for seven days. Healthy volunteers were also given the drug for two weeks. While this time period was not long enough for MRI scans to show visible changes in the accumulation of plaques, samples of the fluid surrounding the brain showed that levels of two compounds that are crucial for the formation of the amyloid proteins had been reduced.
Other attempts have been made to create a drug that inhibits BACE1, but most have caused unacceptable side effects such as liver toxicity. The new drug from Merck seems have few side effects, and it will be the first to show enough promise for next year’s large efficacy trials. Results of the first round of trials are expected to be reported in July of 2017.