Can We Prevent Alzheimer’s? Scientists Say New Tests and Treatments Are ‘A Game Changer’
For years, Alzheimer’s conferences were like the obituary pages in the local newspaper: It’s where clinicians and researchers in the field went to find out the names of the latest promising drugs to die. Between 1998 and 2017 alone, 146 clinical trials of new Alzheimer’s drugs failed.
So when Randall Bateman showed up outside a restaurant in Bar Harbor, Maine, one evening in the fall of 2022 during an industry confab and announced to a couple of tables full of his colleagues drinking on the patio that he had something important to share with them, no one was prepared for what came next.
Bateman, a neurologist and Alzheimer’s researcher at the Washington University School of Medicine in St. Louis, told them he had just received a phone call from his contact at the drug company running the trials of lecanemab, an experimental drug designed to facilitate the removal of the toxic plaques in the brain associated with the disease. The results, set for public release the following morning, were in: In a study of 1,800 Alzheimer’s patients over 18 months, the treatment had reduced the rate of cognitive decline by close to 30 percent.
There was a stunned silence and some sceptical questions. Then the table erupted in applause. “It’s all anybody talked about for the rest of the meeting,” says Bateman. “The agenda was blown. Nobody was paying attention to what we should have been doing. It’s reenergized, recharged, everything.”
The trial results Bateman reported were just the first in a flurry of positive developments. A few months later, the U.S. Food and Drug Administration approved the drug, now marketed as Leqembi. In July, Eli Lilly reported that a second drug, donanemab, had an even greater effect on slowing the progress of the disease, in a study of more than 1,700 Alzheimer’s patients. The FDA is expected to approve it soon. As with Leqembi, many expect that Medicare will eventually agree to pay for it—marking the first time new treatments have become available for the terminal neurodegenerative disease in 20 years.
To be sure, these drugs are not cures. They offer little relief for patients already in the late stages of Alzheimer’s dementia, for whom the effects of the new drugs are modest. They can slow the decline, giving those in whom the disease is moderately advanced an extra year of cognitive lucidity. For those patients and their families that’s certainly significant, but nowhere close to a reversal.
The big potential benefit, say Alzheimer’s experts, lies in using these drugs, or others soon to come, in conjunction with a second recent development in the field: diagnostic blood tests that can identify the presence of Alzheimer ‘s-associated proteins. With many blood tests currently undergoing clinical trials, scientists believe that in a few years, clinicians may be able to use them to make quick, early diagnoses cheaply, even before patients show any outward symptoms of dementia. That suggests a new strategy against the disease: GPs could screen otherwise healthy people for early-stage Alzheimer’s and treat them with drugs that slow the progress of the disease before major damage has occurred. The hope is that eventually, Alzheimer’s will no longer be a terminal disease but a chronic one that can be managed with drugs and perhaps be staved off indefinitely.
There is no guarantee, however, that the drugs and tests now being developed will fulfil this promise. Some scientists, sceptical of the influence of Big Pharma, believe the field is moving too quickly, particularly in starting clinical trials on patients who have no symptoms of dementia. And even with the best drugs and tests, many hurdles would still remain before early detection and prevention could become a standard of care—not least the U.S. healthcare system’s abysmal track record in preventing chronic, slow-developing diseases, such as diabetes and heart disease, that are already eminently manageable in theory.
Still, many Alzheimer’s researchers are calling the new developments, which break a 20-year logjam in Alzheimer’s research, a “game changer.” That is hopeful news for the 13 million Americans who are expected to have the disease by 2050 (up from 11 million today), and millions of their loved ones.
