In the second half of 2021, the world of Alzheimer’s research saw renewed excitement in a class of experimental Alzheimer’s drugs, according to a nonprofit that pushes for the prevention and cure of the disease.
The buzz came amid the news that the U.S. Food and Drug Administration approved Aduhelm, or aducanumab, for the treatment of Alzheimer’s, a memory-affecting disease that worsens over time.
“It is the first new treatment approved for Alzheimer’s since 2003,” the FDA said in a news release.
The Colorado branch of the nonprofit Alzheimer’s Association highlighted some advancements made in understanding the disease in 2021.
The key difference between the new treatment and old methods is that Aduhelm is the first drug approved by the FDA that addresses the underlying biology of Alzheimer’s, said Jim Herlihy, spokesperson for the Alzheimer’s Association’s Colorado chapter.
“All previously approved medications have only provided relief from Alzheimer’s symptoms,” Herlihy said. “These (new) drugs focus on enabling the immune system to clear protein in the brain before it forms the toxic clumps that drive the death of neurons in the brains of those with Alzheimer’s.”
While the specific causes of Alzheimer’s are not fully known, the disease is characterized by changes in the brain — including “amyloid plaques” — that result in loss of neurons and their connections, according to the FDA. Those changes affect a person’s ability to remember and think.
Aduhelm was approved using the “accelerated approval pathway,” which can be used for a drug for a serious or life-threatening illness that provides a meaningful therapeutic advantage over existing treatments, according to the FDA.
The Alzheimer’s drug pipeline heated up last year beyond just the approval of aducanumab, according to the Alzheimer’s Association.
In the second half of 2021, there was renewed excitement in the class of experimental Alzheimer’s drugs that target beta-amyloid, according to the association. Those included drugs from Eli Lilly (donanemab), Eisai (lecanemab) and Roche (gantenerumab), all of which received “Breakthrough Designation” by the FDA in 2021.
COVID in the mix
Research appears to point to a link between COVID-19 and the brain, according to the association.
In July, the Alzheimer’s Association’s international, multidisciplinary coronavirus group presented its first data on the short- and long-term consequences of COVID infection on the brain. The data suggested a link between COVID and persistent cognitive impairment, including the acceleration of Alzheimer’s symptoms.
“Since COVID is relatively new, it is too soon to predict the long-term implications,” Herlihy said. “However, one study conducted over six months in nearly 300 older adults from Argentina who had COVID-19 found more than half had continuing problems with forgetfulness, and 25% had additional problems with cognition.”
The risk of both contracting COVID and serious implications of it are higher as people age, Herlihy noted.
Race remains an issue
Researchers are working to better understand how Alzheimer’s risk and progression differ in different populations, according to the association.
“What is currently known is that Blacks are twice as likely as Whites to develop Alzheimer’s while Hispanics are 50% more likely than Whites,” Herlihy said.
But researchers are also exploring other issues that could influence those trends, he added.
That includes “level of education, the physical environment — air pollution, which can have economic implications, such as proximity to heavy industry, highways — and other factors that may play a role,” Herlihy said. “This research is ongoing.”
Research also pointed to another benefit of exercise on the brain, according to the association.
An August 2021 study found a hormone produced by muscles during exercise can bolster the health of neurons and improve thinking and memory.
“While the results are very preliminary, this offers more evidence that exercise is good for the long-term health of the brain,” according to the news release.
Blood tests for Alzheimer’s took a major step forward, according to the association.
“We’ve seen advances in the development of blood tests that provide a simple, accurate, non-invasive way to detect Alzheimer’s years before symptoms appear. Now, they’re being used to screen people for participation in a new clinical trial to prevent memory loss,” the news release said.
If drugs prove effective in limiting the progression of the disease in people’s brains, earlier diagnosis will be key in helping people, Herlihy said.
Any test, such as ones involving blood, eyes or saliva, “would be less invasive and less expensive than brain imaging or other current tests and could be made part of an annual physical,” Herlihy said. “There are a number of blood tests in the research process, but none have received FDA approval yet.”