Lecanemab Is a New Drug to Slow Alzheimer’s Disease

The memory loss and cognitive decline caused by Alzheimer’s disease are devastating — even worse, no cure and few treatments exist for it. 

Now that is starting to change. The Food and Drug Administration (FDA) recently approved a new medication called lecanemab, or Leqembi, that helps slow cognitive decline in people with early-stage Alzheimer’s.  

“This is a really exciting moment, not just for behavioral neurology but for the field of medicine as well,” says Dr. Michael Rosenbloom, a neurologist at the Memory and Brain Wellness Center at Harborview Medical Center.

And, of course, it’s exciting for prospective patients. 

How does lecanemab work?   

Lecanemab is given via intravenous (IV) infusion, not a pill. It’s administered every two weeks for as long as 18 months. (More research is needed to understand if giving someone lecanemab for longer is beneficial.) 

The brains of people with Alzheimer’s don’t properly clear away proteins called amyloid, which leads to the proteins building up and forming clumps. This accumulation is thought to cause brain damage that leads to memory loss and cognitive decline. Lecanemab binds to these plaques and alerts the immune system to remove them.  

In research, lecanemab was shown to slow cognitive decline by 27%. This may not seem like a lot, but for someone who has Alzheimer’s and their family and loved ones, it gives hope for delaying the effects of the disease. 

What’s even more exciting is that lecanemab is just the start: There is one other, similar drug that has shown promise in research studies and is on track for FDA approval soon. 

Who is eligible for the new treatment?  

Currently, only people who have early-stage Alzheimer’s disease can take lecanemab. That means people who were recently diagnosed and have mild cognitive impairment (this is different from early-onset Alzheimer’s).

Some of the first signs of Alzheimer’s disease are things like short-term memory issues (someone forgetting things they just learned), having a hard time planning or problem-solving, having a hard time completing normal, daily tasks and routines, and things like personality changes and withdrawing from social activities. 

The drug has not yet been tested in people with later-stage Alzheimer’s or people with other types of dementia, so doctors don’t know yet if it will work for those patients.  

How can I or a loved one get a lecanemab prescription?  

The FDA requires that anyone who is eligible for and interested in lecanemab get tested first to confirm they have amyloid in their brain. This can be done either by a spinal tap or a PET scan that detects amyloid.  

The treatment does have side effects: the most concerning are swelling and mild bleeding in the brain. But, as scary as that sounds, most people who develop these conditions don’t have symptoms and even fewer have life-threatening complications. But because of the danger, patients are monitored with brain scans over the course of treatment. 

If you’re interested in lecanemab for yourself, a family member or a loved one, talk with your or their doctor. The drug is still being rolled out at different facilities — the Memory and Brain Wellness Center is one of them.  

Doctors from the Center are also involved in a study that is currently enrolling patients and will learn more about if lecanemab is effective in patients who don’t currently have Alzheimer’s but have higher levels of amyloid in the brain and are at higher risk for developing it.  

Michael McCarthy contributed to this article. A version of this story originally appeared on the UW Medicine Newsroom.