Scientists have identified a promising new class of treatments for Alzheimer’s disease, and they’re already widely used to treat HIV and hepatitis B.
Along with their antiretroviral effects, drugs called nucleoside reverse transcriptase inhibitors (NRTIs) inhibit the activation of inflammasomes, which, as the name suggests, are mechanisms that trigger inflammation.
This inflammasome blocking was the reason the US research team was looking at NRTIs. They analyzed information from two large health insurance databases in the US on 271,198 people aged over 50 with either HIV or hepatitis B.
The individuals in this group with a history of taking NRTIs showed “significant and substantial reductions” in their risk of developing Alzheimer’s, compared to those who were receiving different treatments.
In the Veterans Health Administration database, composed of mainly older males, that reduction in risk was 6 percent for every year of taking NRTIs.
The MarketScan database, which the team notes includes “a broader, commercially insured population with a more balanced age and sex distribution”, showed that risk reduction was 13 percent for every year of NRTIs.
It’s not a direct sign of cause and effect due to the observational nature of the study, but it’s a strong association that’s well worth investigating further.
“The reduction in risk was observed in two large, diverse health insurance databases after correcting for numerous comorbidities known to be associated with Alzheimer’s disease,” write the researchers in their published paper.
Inflammasomes act like alarms triggering inflammation in the body, and are thought to be involved in the way Alzheimer’s takes hold in the brain.
While scientists aren’t sure exactly how Alzheimer’s gets started, it’s clear that neuroinflammation triggered by the buildup of amyloid-beta and tau proteins is somehow involved, and could give us a way into treating the disease.
Repurposing existing drugs offers one way of developing Alzheimer’s treatments more quickly, and the researchers behind this new study now want to see clinical trials of NRTIs for Alzheimer’s. Work is already underway to tackle some of the side effects that can come with these drugs, which include liver problems and impacts on the nervous system.
“We have also developed a new inflammasome-blocking drug called K9, which is a safer and more effective version of NRTIs,” says ophthalmologist Jayakrishna Ambati, from the University of Virginia.
“This drug is already in clinical trials for other diseases, and we plan to also test K9 in Alzheimer’s disease.”
We’re now seeing regular progress in understanding more about Alzheimer’s and developing potential treatments for the disease. While this latest study only looked at people with specific medical conditions, the findings are notable enough to justify broader research into ways of regulating inflammation in the body.
“It’s estimated that over 10 million people around the world develop Alzheimer’s disease annually,” says Ambati. “Our results suggest that taking these drugs could prevent approximately 1 million new cases of Alzheimer’s disease every year.”
The research has been published in Alzheimer’s & Dementia.
