En español | After years of setbacks, things are looking a little more hopeful on the Alzheimer's treatment front. Biogen is waiting to hear whether the Food and Drug Administration will approve its somewhat controversial antibody therapy, aducanumab. If it gets the green light, aducanumab would be the first drug available to slow the progression of Alzheimer's disease, not just treat its symptoms. And earlier this year, Eli Lilly announced positive results from a phase 2 clinical trial, finding its experimental drug, donanemab, may delay cognitive decline in people in the early stages of Alzheimer's disease.
Even as researchers inch closer to a major breakthrough, experts aren't ready to hang their hats on one specific treatment to bring relief to the more than 6 million Americans who suffer from Alzheimer's disease. More than 200 government-funded studies and clinical trials are underway, and many of them could hold an answer for ending Alzheimer's.
"The growing realization” among people who study Alzheimer's and related dementias “is that the underlying processes and pathologies that lead to dementia can be very diverse,” explains Richard Hodes, director of the National Institute on Aging (NIA) at the National Institutes of Health (NIH). And so different people may require different treatments — or a combination of a few — depending on what's driving the progression of their disease.
This tailored approach, known as precision medicine, is the topic of an NIH Alzheimer's research summit taking place this week. You may have heard of precision medicine in cancer care, where doctors piece together specific treatments based on a person's genes or the genetic changes in their cancer.
"We're discovering that maybe a similar approach could be taken with Alzheimer's disease,” says Eliezer Masliah, director of the NIA's Division of Neuroscience. “Not all cancers are the same or are created equal. And I think the thing we can say about Alzheimer's disease and related dementias is not all of them are the same.”
Researchers explore diverse ‘targets’ for answers
To get to the point where physicians can help prevent Alzheimer's in people at risk, or help those diagnosed with the disease avoid its debilitating symptoms, scientists are studying a variety of so-called targets for intervention.
At the forefront is amyloid, a protein that clumps together and forms plaques in the brains of people who have Alzheimer's. Both aducanumab and donanemab — the two experimental drugs making headlines — are designed to cling to and clear these toxic plaques. Another popular target, and also a hallmark of Alzheimer's disease, is tau, which forms abnormal tangles inside the neurons, disrupting cell function in the brain.
Inflammation has become “a major subject and target for therapeutics” as well, Masliah points out. Chronic inflammation is often seen in the brains of people who have Alzheimer's. It sets in when microglia cells, which normally keep the brain free of waste and toxins, fail to do so, according to the NIA.
Among a myriad of other targets, researchers are also looking at the connections between neurons, called synapses, which break down in the disease course, in hopes of learning whether it's possible to enhance their function or “reestablish the rhythm of those connections in the brain,” Masliah says.
Even still, “just targeting [amyloid] or just inflammation or just synapses is not going to be enough,” he adds. “We're probably going to have to combine some of these things. And those combinations might be unique for different populations.” Lifestyle interventions such as sleep and blood pressure management may also be a part of the equation.
Closing in on a breakthrough
While it's hard to predict a timeline for treatments that will stop or slow these changes in the brain, Hodes says the current pace of research leads him to be “optimistic.”
Advances in blood and imaging biomarkers, which help scientists predict or identify Alzheimer's disease and monitor its progression, have aided in this acceleration by making it easier for researchers to screen trial participants and study interventions at earlier stages of the disease — ideally, before symptoms set in.
Another factor that can influence the treatment timeline: participation. With hundreds of studies underway, there are more opportunities than ever for people to take part in clinical trials and other Alzheimer's research projects. (For more information on research opportunities near you, visit alzheimers.gov.)
"We're getting closer [to a breakthrough], and we're getting closer at a more rapid rate,” Hodes says.
Rachel Nania writes about health care and health policy for AARP. Previously she was a reporter and editor for WTOP Radio in Washington, D.C. A recipient of a Gracie Award and a regional Edward R. Murrow Award, she also participated in a dementia fellowship with the National Press Foundation.