A statin-like drug could prevent the onset of Alzheimer’s disease in later life, according to scientists who believe the medication might one day be taken by millions of healthy people in their 30s and 40s.
Preliminary lab tests show bexarotene can block the build-up of a key brain protein linked with the early development of Alzheimer’s, although clinical trials on humans are still years away, scientists said.
The drug is already an approved cancer treatment, so switching its use would not require the extensive safety testing needed fora new drug, researchers said.
Bexarotene appeared to prevent the onset of Alzheimer’s in nematode worms that had been genetically programmed to suffer the same accumulation of amyloid beta protein seen in the brains of people with the disease.
If further work shows the same effect in humans, it raises the possibility of bexarotene becoming the first “neurostatin” that can be taken to lower the risk of developing the disease in later life, said Professor Michele Vendruscolo of Cambridge University.
“The same way statins reduce the risk of heart disease, neurostatins decrease the risk of Alzheimer’s disease. They prevent the initial events,” Professor Vendruscolo said.
“The body has a variety of natural defences to protect itself against neurodegeneration, but as we age, these defences become progressively impaired and can get overwhelmed. By understanding how these defences work, we might be able to support them by designing drugs that behave in similar ways,” he said.
A study in Science Advances journal indicated that bexarotene, which is licensed for the treatment of lymphoma, blocks the “primary nucleation” of the amyloid-beta protein seen in the early stage of Alzheimer’s. This prevents amyloid beta from aggregating together in the brain to form protein “plaques”, he said.
“If you stop the process before aggregation has started, you can’t get proliferation,” Professor Vendruscolo said. “The evidence is that this problem of amyloid-beta aggregation is starting in your 40s, perhaps even earlier. So it would not be a bad idea to start taking these neurostatins in your 30s,” he added.
Professor Chris Dobson at Cambridge said: “You wouldn’t give statins to someone who had just had a heart attack, and we doubt that giving a neurostatin to an Alzheimer’s patient who could no longer recognise a family member would be helpful. But if it reduces the risk of the initial step, then it has a serious prospect of being an effective preventive treatment.”
Rosa Sancho, head of research at Alzheimer’s Research UK, said the accumulation of amyloid protein is a hallmark of Alzheimer’s and that drugs to halt this build-up could help protect nerve cells from damage and death.
Over the next 35 years, the number of people in the world with Alzheimer’s disease is predicted to grow from 40 million to 130 million, with 70 per cent of those in middle or low-income countries.
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