How a new FDA-approved drug can — and can’t — help people with Alzheimer’s

Here’s what you need to know about Leqembi, the latest treatment on the market.


Couple hugging

If you have a loved one with Alzheimer’s disease, you may have read about a newly approved drug. And you may have heard that the drug has caused some controversy. So, what’s really going on?

In early 2023, the U.S. Food and Drug Administration (FDA) granted accelerated approval to a new Alzheimer’s drug called Leqembi. (Biogen, a biotechnology company, and Eisai, a pharmaceutical company, collaborated on it.)

Leqembi’s approval made headlines, and for good reason. More than 6 million Americans live with Alzheimer’s. And 1 in 3 adults ages 65 and older dies with it or another form of dementia, according to the Alzheimer’s Association.

Leqembi has been shown to successfully reduce amyloid plaques in the brain. (It’s actually the second drug shown to do this; the first one was Aduhelm.) Amyloid plaque is a substance that may lead to tissue loss in parts of the brain related to memory, thinking, and learning. It’s one of the hallmarks of Alzheimer’s disease.

So, what exactly does this drug do? And how effective is it, really? Find out below.

Did you know that access to BrainHQ may be included with your Medicare Advantage plan? Check your eligibility today.

What Leqembi does and doesn’t do

Leqembi targets amyloid plaques in the brain. It’s a monoclonal antibody that is delivered through an intravenous (IV) infusion every four weeks. Monoclonal antibodies are man-made proteins that can bind to certain targets in the body.

“The antibodies go up to the brain and attack the plaque,” says Dung Trinh, M.D. He’s the founder and chief medical officer of the Healthy Brain Clinic in Long Beach, California. “They kind of light it up for the immune system to recognize, and then the immune system does its job in removing the plaque.”

The 18-month clinical trial of Leqembi involved 856 patients with early Alzheimer’s disease. That means they were in the mild cognitive impairment or mild dementia stage of the disease. Researchers found a significant reduction in brain amyloid plaques that were seen on imaging tests of patients’ brains. And crucially, they found that the drug slowed the cognitive decline that is the most important part of Alzheimer’s disease.

But Leqembi did not halt the progression of Alzheimer’s. Nor did it restore any memory loss. But it did buy patients some extra time, says Dr. Trinh.

Scientists are excited to see anything with a measure of success after two decades of failure. “It’s a breakthrough, it’s progress, but it’s not a slam dunk,” Dr. Trinh says.

Smiling women on a beach
Want to get more great articles on brain health?

Sign up for our brain fitness newsletter and get research-backed tips and activities delivered straight to your inbox.

Leqembi’s side effects and other potential issues

Leqembi offers doctors the first new Alzheimer’s treatment option in years. But it also has some possibly dangerous side effects. Those include:

  • Swelling of the brain (edema)
  • Small spots of bleeding in the brain (microhemorrhages)

These side effects happen to about 1 in 5 patients who take the drug, notes Dr. Trinh. The better news: In most patients, those side effects haven’t been serious, or even noticeable sometimes.

However, Dr. Trinh does warn that Leqembi could be fatal if taken with certain strong blood thinners such as Coumadin (warfarin). “I’m talking about blood thinners people go on when they have blood clots in the lungs or atrial fibrillation,” he says. (Atrial fibrillation is an irregular, often rapid heartbeat that can cause poor blood flow.)

Also, Leqembi has only been tested in people with the earliest stages of Alzheimer’s disease. Doctors don’t know if it will slow the decline in people with moderate or severe Alzheimer’s, or other types of dementia.

If you think your loved one might benefit from Leqembi, it’s a good idea to talk to their doctor. They can help discuss potential benefits, side effects, and other factors to determine whether Leqembi might be right for them.

Will Leqembi be covered by Medicare?

Just because the FDA approves a drug doesn’t necessarily mean that Medicare will pay for it for all patients. Before Leqembi was approved, another similar medication was approved called Aduhelm.

But while Aduhelm clearly removed Alzheimer’s plaques, Medicare wasn’t convinced that it really helped patients. So, Medicare only covers Aduhelm for Medicare members who are enrolled in clinical trials. “Aduhelm never took off,” Dr. Trinh says. “It was approved, but there was so much controversy around that approval that it never launched.”

The Centers for Medicare & Medicaid Services hasn’t approved Leqembi for everyone on Medicare yet either. For now, the same rules apply to Leqembi as they do Aduhelm.

“The next questions will be whether Medicare covers it, how much would it cover, and under what setting,” says Dr. Trinh.

Without Medicare coverage, Leqembi costs $26,500 per year. Also, there are additional costs for brain imaging to ensure that a patient is eligible for the drug, and to monitor the safety risks.

While Alzheimer’s patients wait for more news on Leqembi, there may be a third Alzheimer’s drug hitting the market as early as this year. It’s called donanemab, a drug from pharmaceutical giant Eli Lilly. If the FDA approves donanemab, it could come later this year. But that doesn’t guarantee that Medicare will cover it either.

Access to BrainHQ may be included with your Medicare Advantage plan. Check your eligibility today.

What the future holds

It’s true that Leqembi and other Alzheimer’s drugs don’t offer a cure for the disease. But Dr. Trinh, who is involved in ongoing clinical trials at Healthy Brain Clinic, is optimistic about the future of Alzheimer’s treatments.

“I see medications in the pipeline that potentially will be even better than what we have,” he says. “My hope is that this opens an entire door of hope for Alzheimer’s patients.”

Many scientists are excited by the prospect of keeping people’s brains healthy before they develop Alzheimer’s disease — and before they need expensive drugs. A recent editorial in the medical journal Lancet pointed out that up to 40% of dementia cases might be preventable by people adopting more brain-healthy lifestyles.

Studies show that brain training and physical exercise can improve cognitive function and brain health — which might protect against the onset of dementia in the first place. And the National Institutes of Health has funded two big studies with BrainHQ (the PACT study and the ACTIVE MIND study) to answer that exact question.

Dr. Trinh is excited about the future. “We have 6 million Americans with Alzheimer’s,” he notes. “And they can’t wait for a perfect drug.”

Looking for more ways to build a healthy brain? Try BrainHQ, a brain-training program designed by leading scientists that rewires the brain to help you think faster, focus better, and remember more. And it may be included at no cost with your Medicare Advantage plan. Check your eligibility today.

Additional sources
Alzheimer’s facts and figures: Alzheimer’s Association
FDA approval of Leqembi: U.S. Food and Drug Administration
Leqembi study: New England Journal of Medicine
Aduhelm background: Alzheimer’s Association
Pricing information: Eisai
Donanemab: Eli Lilly
Dementia stat: Lancet