There is big news in the fight against Alzheimer’s disease: The first drug that’s been proven to slow the progression of Alzheimer’s disease just received full approval from the U.S. Food and Drug Administration (FDA).


Alzheimer’s disease impacts nearly six million Americans.  All indications are that more are expected to be diagnosed with the condition in the future.  Alzheimer’s is the sixth leading cause of death in the US, according to the Centers for Disease Control.  There is currently no cure for the disease, but experts say a new drug called Leqembi (“la-kem-BE”) may help patients have a better quality of life.

Lecanemab (“lee-can-E-maab”) sold under the brand name Leqembi is a new medicine that may help people with Alzheimer’s disease, which is caused by sticky clumps of protein in the brain called amyloid plaques. Leqembi helps remove some of these clumps and slow down the disease. The FDA let Leqembi be sold in January as a safe medicine, but they did not confirm that it really works. The FDA allowed the sale of Leqembi on the condition that the medicine makers did more tests to prove that it actually helped people with Alzheimer’s disease.  The drug was approved in January under the FDA’s Accelerated Approval pathway.


There have been a couple of studies on the effectiveness of Lecanemab. The New England Journal of Medicine published results of a clinical trial conducted at 235 different medical sites across North America, Europe, and Asia that found that lecanemab reduced cognitive and functional decline in patients with Alzheimer’s disease by 27 percent. It also found that patients who took the medication had more amyloid plaques cleared after 18 months on the drug.

The trial included 1,795 adults between 50 and 90 years of age with mild cognitive impairment due to early Alzheimer’s disease or mild Alzheimer’s disease-related dementia.  Half of the participants received lecanemab via IV infusion every two weeks, with the other half getting a placebo. Participants in each group had a clinical dementia rating of about 3.2 when the trial began. (Note: A higher score means someone has more cognitive impairment.)

At the end of the 18-month trial, the group that received lecanemab had an average score that increased by 1.2 points (total of 4.2).  In the group that received the placebo, however, it went up nearly 1.7 (total of 4.9) points, a 27 percent difference.

According to the FDA, lecanemab “demonstrated a statistically significant and clinically meaningful reduction of (cognitive) decline from baseline to 18 months on the primary endpoint” compared to a placebo.


Not all the news is good.  Leqembi is very expensive and has some safety concerns.

Leqembi costs about $26,500 per year, and Medicare patients may have to pay 20% of that amount out of pocket.  Leqembi is not a Part D drug, which means that the new law that caps Part D out-of-pocket spending at $2,000 starting in 2025 will not apply to it. Medicare will only cover Leqembi for patients who have mild cognitive impairment or mild dementia with confirmed amyloid plaques and who enroll in a patient registry or a clinical trial. Some private insurers have also refused to cover Leqembi, citing doubts about its effectiveness and safety. Therefore, access to Leqembi may be limited and costly for many patients who could benefit from it.

To have Leqembi covered by Medicare, your physician must determine that you meet the clinical criteria for the treatment, and his or her practice would need to be part of a qualifying registry that allows for consistent follow-up care.

It’s important to note that lecanemab is not perfect. “There are major risks around bleeding and brain swelling,” says Amit Sachdev, M.D., medical director for neurology and ophthalmology at Michigan State University and the principal investigator for the lecanemab clinical trial program.


“Patients will need solid evidence that they have Alzheimer’s and need to have easy access to emergency care if they choose to go on the drug,” Dr. Sachdev says. “Brain swelling and bleeding are very serious side effects, and minor neurologic symptoms such as dizziness and headache could be due to such swelling.”

The actual impact on patients can vary. “For those patients who are later in their disease, it may not have a big impact,” Dr. Sachdev says. “For patients earlier in their disease, this could be a useful tool for slowing progression.”

Paul Newhouse, M.D., clinical core director of the Vanderbilt Alzheimer’s Disease Research Center, says it may take a few months before lecanemab is able to be administered at major medical centers. “It’s going to take us a little bit of time to set up a procedure to get this administered—there are many steps involved,” he says. “We have to properly screen patients, get patients genetically screened, and then set up the infrastructure to properly administer this.”

While lecanemab comes with the risk of potentially serious side effects, Dr. Sachdev says he’s “excited” for patients and their families. “The medication is far from perfect, but even having a chance to have a discussion is remarkable,” he says.