The Food and Drug Administration has approved a drug that can help people in the early stages of Alzheimer’s maintain their mental abilities.
Lecanemab, which will be marketed as Leqembi, is likely to reach far more patients than a similar product, Aduhelm, which failed after receiving a controversial approval in 2021.
“This is a milestone for people eligible for this treatment, for their families, for the research community,” says Maria Carrillo, scientific director of the Alzheimer’s Association.
But Leqembi, like Aduhelm, can cause swelling or bleeding in the brain, which means patients need to have regular brain scans after starting treatment. It’s also unclear whether Medicare and private health insurers will cover the drug, which will likely cost tens of thousands of dollars each year.
Eisai and Biogen, the companies that developed Leqembi, have not yet announced pricing.
The new drug, which is given intravenously every two weeks, removes a substance called amyloid from the brain. Sticky amyloid plaques are a hallmark of Alzheimer’s disease, although many previous drugs that targeted amyloid have failed to slow patients’ loss of mental abilities.
In a study of 1800 people with early Alzheimer’s, those who took Leqembi for 18 months experienced 27% less decline in memory and thinking.
That’s a modest benefit, says Dr. Joy Snider, a professor of neurology at Washington University School of Medicine in St. Louis.
“It’s not a cure. It doesn’t completely stop the disease. It doesn’t make people better,” says Snider. “But it slows the progression into very mild disease.”
And even a modest slowdown could be meaningful for patients and their families, says Snider, who helped lead the study that found a benefit.
“Maybe you could continue driving for another six months or a year,” he says. “Maybe you could keep doing your checkbook for another six months or a year.”
It could be many months, though, before Leqembi reaches many of the millions of patients who could benefit from it.
To qualify for treatment, people must undergo tests that prove they are in the early stages of dementia and that their brains contain the amyloid deposits that are a hallmark of Alzheimer’s. That process is likely to include at least two visits to specialists, which are in short supply.
The result is likely to be a very long tail, says Jakub Hlávka, a health policy expert at the University of Southern California.
“Roughly speaking, we can expect it to be about five years before all currently eligible patients can make it through that queue,” he says.
Leqembi has received what is known as accelerated approval, a conditional permit to market a drug based on its ability to remove amyloid from the brain. The FDA is likely to consider a full approval later this year, after reviewing evidence that the drug also helps preserve mental function.
Carrillo is confident the drug will receive full approval.
“The science speaks for itself,” he says. “Science is telling us that lowering amyloid is leading to clinical benefits.”
But until Leqembi gets full FDA approval, Medicare is unlikely to cover it.