Several pharmaceutical companies are currently developing drugs that target Alzheimer’s disease.
Developping a new drug takes years, and until now, no therapeutic has been able to thwart the development of the disease.
But there is hope.
Two leading drugs are currently undergoing stage 3 clinical trials. This is the last step prior to commercialization.
One of them is an antibody that targets beta-amyloid proteins before they form plaques.
It is called Aducanumab.
This antibody was first identified in the blood of aged donors with normal cognitive function.
Scientists hypothesized that this antibody protected them from developing the disease.
Biogen, the pharmaceutical company behind these trials, published results from its stage 1 clinical trial last September in an article in Nature.
This study involved 165 patients that had a prodromal, or mild, Alzheimer’s disease. One year after monthly intravenous infusions of the drug, patients showed reduced levels of brain amyloid-beta proteins in a dose-dependent manner. They also showed signs of decelerated clinical decline.
Two stage 3 clinical trials involving this drug have been underway since 2015. They involve around 2,700 patients.
According to Biogen, preliminary results from these studies will be released at the beginning of 2020. The studies will be completed by 2022.
A second drug
That said, we might have news about a different Alzheimer’s treatment before long…
The drug is called Verubecestat. It is also undergoing two phase 3 clinical trials, one of which is expected to end in 2017. Over 3,700 patients take part in these studies. (EDIT: Merck halted one of the two studies in February.)
Verubecestat is a BACE1 inhibitor. By blocking the activity of this protein, the drug prevents the production of amyloid-beta proteins.
The amyloid-beta proteins are among the leading suspects when it comes to Alzheimer’s disease. They form plaques in the brains of Alzheimer’s patients, and are thought to trigger the disease, although this hypothesis has yet to be confirmed.
The drug was used in a phase I clinical trial in 2012 involving 32 patients living with mild to moderate Alzheimer’s disease. The results of that study were recently published in Science Translational Medicine.
According to the authors, once-daily doses of Verubecestat for one week reduced up to 84 % of the levels of amyloid-beta peptide production in the cerebral spinal fluid.
Phase 3 studies will evaluate whether this biological effect translates into slowing the development of Alzheimer’s disease.
One candidate failed
Unfortunately, the news is not as good for the pharmaceutical company Eli Lilly. Its drug, Solanezumab, did not meet the primary endpoint in a phase 3 clinical trial as the company stated last November.
The drug had no significant impact on slowing the cognitive decline of patients compared to controls. It was also unable to reduce the accumulation of amyloid-beta proteins in the brain.
That said, there is still a lot of research going on in the field. Around 80 therapeutics are currently in phase 2 or a phase 3 clinical study.