In the struggle to cure Alzheimer’s disease, results from clinical trials of a new drug look promising in both understanding its cause and reducing its impact.
Flossing your Brain Plaque
The drug, called Aducanumab, is produced by American biotechnology firm Biogen. It works by inciting the body’s immune system to identify and attack amyloid beta, a protein that grows in clumps in the brain, forming plaque that many suspect is the cause of Alzheimer’s.
Researchers developed the drug by studying the brain chemistry of older individuals who do not have Alzheimer’s or dementia. They came across an immune compound that seemed to be keeping brains plaque-free, synthesized it, tried it on animals, and found that it effectively targeted and cleared amyloid beta clumps.
Unprecedented Efficacy
In recent human trials, researchers gave 165 patients an injection of either Aducanumab or a placebo once a month for a year. While there was little change in the control group, those receiving the drug showed stark reductions in the amount of amyloid beta in their brains, as identified with magnetic resonance imaging scans. Additionally, there was a direct correlation between amount of drug received and amount of protein eliminated.
MRI scans taken during the drug trial demonstrate its effectiveness at clearing amyloid beta plaques, which show up as red.
Describing the patients’ MRI scans, co-author of the study and director of the Institute for Regenerative Medicine at the University of Zurich Dr. Roger Nitsch explains that “after one year, you can see no red on the image, meaning the amyloid has almost completely disappeared.” While discussing the results published this summer by Biogen, he also explained that compared to other studies published in the past, the effect size of this drug was unprecedented.
Biogen’s headquarters in Cambridge, Massachusetts.
Towards a Confirmed Hypothesis
The hypothesis that amyloid beta kills neurons and causes Alzheimer’s has been around since the early 1990s. Since then, thousands of experiments have been done to confirm it, and many drugs have been developed that target the protein. These drugs have so far failed to make a significant dent in treating the disease, leading many to question the hypothesis.
So far, this research has only shown that the drug can clear amyloid beta, not that it can cure Alzheimer’s disease. It is however more effective at this task than any previous drug, and Biogen notes that there have been some hints that it can restore cognition. It is now launching a new research phase that will specifically test for this, due to complete in 2020. If successful, this would confirm the amyloid beta hypothesis and provide an important tool in treating the disease and its symptoms for the millions of people afflicted.
Lab at Biogen where Aducanumab is being developed.
From Reactive to Proactive Treatment
Additionally, a drug like this could become a preventive measure in the future. As Biogen’s chief medical officer Dr. Al Sandrock envisions: “Everyone gets genotyped after a certain age, and if you have a certain genetic makeup, then those people might have amyloid looked for using a biomarker. If you have the amyloid, I see people starting treatment very very early. Some people are now talking about even treating before symptoms.”
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Photo source: Raymond – Technosmart.
Photo credits: Onur Senturk & Troublemakers.