Scientists have developed a drug they hope will benefit people with Alzheimer’s disease, which afflicts an estimated 44 million people around the world. The new compound sweeps away abnormal protein clumps in the brain which are a hallmark of the neurodegenerative disorder.
In a study reported in the journal Science Translational Medicine, researchers describe how a synthetic drug, called antisense oligoneucleotide, reduced the production and in some cases cleared clumps of tau in the brain.
Tau bundles are one of the hallmarks of the disease, along with beta amyloid deposits, another destructive protein.
By stopping the formation of tau, researchers at Washington University School of Medicine in St. Louis, Missouri, found they could extend the lives of mice that were bred to have collections of human tau in their brains.
Lead author Sara DeVos said scientists saw an improvement in their condition.
“So these mice die earlier than normal. So when we treat with our drug, the mice live longer and we can also prevent neurons from dying. So if we give this drug, the neurons will no longer die as a result of these tau bundles,” said DeVos
The investigators also tested the compound in monkeys and saw positive results.
Human testing expected soon
Antisense oligneucleotide targets the genetic instructions for building tau. The molecule binds to messenger RNA, which carries out the DNA blueprint for life, preventing tau from being produced. The drug can be made to target RNA for destruction of any protein, said scientists.
Tim Miller, a professor of neurology at Washington University and senior author of the study, hopes the drug, developed with Ionis Pharmaceuticals, will soon be tested in humans with Alzheimer’s disease.
“The most exciting and most interesting … is to apply this to people who we presume have abnormal tau to test the hypothesis whether lowering tau in those people will be of benefit to those people,” he said.
Other types of antisense oligoneucleotides have been approved by U.S. regulators and are being used to treat the neurodegenerative disease muscular dystrophy and spinal muscular atrophy. The compound is in clinical trials for Huntington’s disease and ALS, also known as Lou Gehrig’s disease.
Because tau deposits are only a piece of the puzzle that causes Alzheimer’s, the investigators envision using the drug with other treatments, also in development.
There is no cure for Alzheimer’s disease, which primarily strikes senior adults, leading to a decline in mental functioning and eventually death.