Treatments for Alzheimer’s disease seemed unlikely just a few months ago. For 20 years, drug trials have tried unsuccessfully to produce treatments capable of stopping the progression of the disease, and several large pharmaceutical companies have completely abandoned the mission of developing treatments for Alzheimer’s disease. The only hope for improvement for patients, therefore, were drugs that alleviated the symptoms of the disease – such as memory loss, insomnia, and loss of language or reasoning skills – for a limited period of time.
Today, the world of treatments for Alzheimer’s disease could finally open up. Last week, Brigham and Women’s Hospital announced it would conduct the first human trial of a nasal vaccine against the disease, designed to prevent or slow its progression. The trial is small – 16 people aged 60 to 85 with symptoms of Alzheimer’s will receive two doses of the vaccine one week apart. But it draws on decades of research suggesting that boosting the immune system may help clear beta-amyloid plaques in the brain.
These sticky plaques are a hallmark of Alzheimer’s disease. They form when pieces of the beta-amyloid protein build up between nerve cells, which can interfere with a person’s ability to think or remember information.
The vaccine sprays a medicine called Protollin directly into the nasal passage, with the aim of activating immune cells to remove plaque. The concept isn’t entirely new, but it’s particularly promising now that scientists have a better understanding of how to treat the disease, Jeffrey Cummings, professor of brain science at the University of Nevada in Las Vegas, told Insider.
“The idea of activating immune cells is becoming more and more central in the perspective of treating Alzheimer’s disease,” said Jeffrey Cummings. He added that a nasal spray might be more effective at delivering protollin to immune cells than an infusion or inhaler.
The results of the trial may tell us more about how to counteract the progression of the disease, since participants must be at an early stage of their disease and otherwise in good health. However, before the nasal vaccine can be tested on a larger scale, researchers must demonstrate that it is safe and determine the dose to be administered.
Controversial new drug for Alzheimer’s disease approved
The nasal vaccine trial comes in a prolific year for Alzheimer’s disease treatments. In June, the Food and Drug Administration (FDA), the US administration of drugs, approved the first new drug for Alzheimer’s disease in almost 20 years, an antibody infusion called Aduhelm. But that approval quickly became controversial: Many scientists questioned whether the drug deserved the FDA green light, given that it did not permanently improve memory or cognition in clinical trials.
Aduhelm has been shown to reduce the level of sticky plaque in the brains of patients with Alzheimer’s disease, but an FDA advisory committee determined that there was not enough evidence to confirm that this drug worked as a treatment. This skepticism was in part caused by the fact that the drug’s maker, Biogen, halted late-stage clinical trials in 2019 because it assumed the drug would fail. Then, about six months later, a small group of participants started showing positive results.
“Biogen stopped the trial thinking it was in vain, then followed the patients, and it turned out it was not in vain – but, of course, this created a great deal of controversy in the interpretation of the data, ”said Jeffrey Cummings.
The FDA voted to approve the drug under a special fast-track process, which allows drugs to be approved that may benefit patients, even when there is uncertainty about their effectiveness.
Scientists say they have ‘turned a corner’ in disease research
As many as 5.8 million Americans live with Alzheimer’s disease – one of the leading causes of death among American adults. Nearly 122,000 Americans died from the disease in 2019, according to the latest data available.
Deaths from Alzheimer’s disease are also on the rise as the American population ages. From 1999 to 2019, the death rate linked to Alzheimer’s disease in the United States increased by 88% – going from 16 deaths per 100,000 people to 30 deaths per 100,000 people. This death rate can be underestimatedbecause people with cognitive decline sometimes have trouble finding a diagnosis of Alzheimer’s or suffer from other health problems.
But over the past five years, new technologies like brain scans and blood tests have made it easier to confirm Alzheimer’s diagnoses and measure the effectiveness of treatments, Cummings said. “I feel like we have taken a step forward,” he said.
Besides Aduhelm, he added, a few other antibodies have shown promise. Pharmaceutical company Eli Lilly plans to submit data for its Alzheimer’s drug, donanemab, to the FDA by the end of the year, putting it on track for approval in 2022. Two other companies, Biogen and Eisai, are jointly completing an FDA clearance request for their antibody drug, lecanemab.
“These other drugs, which look a lot like Aduhelm, appear to be producing ‘clinical benefit’,” said Jeffrey Cummings. And to add: “This is the key: do patients get better, or at least do they lose their cognitive abilities less quickly, if they are treated? This seems to be true for this whole class of drugs.”
Original version : Aria Bendix / Insider
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