There’s some rare good news in the effort to treat Alzheimer’s disease. The Food and Drug Administration (FDA) recently approved the first drug shown to slow the disease’s progression.
In clinical trials involving 1,795 participants, Leqembi (generic name: lecanemab), manufactured by Eisai in partnership with Biogen Inc., appeared to slow declines in memory and cognition by about 27% after 18 months of treatment, according to a recent NPR story.
More good news: Leqembi is expected to be covered by Medicare, which serves Americans who are 65 and older. This development means more people in the early stages of the disease will have affordable access to the drug.
We talked to Dr. Robert Wiggins, a neurologist with Novant Health Neurology & Sleep - Midtown and interim director of Novant Health’s Memory Care Center in Charlotte, about what this could mean for the millions of people living with Alzheimer’s.
Let’s start with what Alzheimer’s disease is.
It’s a progressive, neurological condition that can lead to dementia. And dementia is a neurological condition that results in severe trouble with memory. Alzheimer’s damages and kills nerve cells in the brain. Over time, it can result in the inability to recall, reason, speak and recognize even people and places that were once familiar to us.
Worried about your memory? Start with your primary care doctor.
I see a lot of patients who have Alzheimer's dementia, which is a specific type of dementia. It’s characterized by trouble with daily functioning. Alzheimer's is the most common form of dementia in America. And it can happen at any age, but it’s more common as we get older.
The first sign of Alzheimer’s is memory loss that interferes with daily life.
How significant is FDA approval of this new drug?
Very. For a long time, we didn’t have any medications that could change the course of the condition – nothing that would be what we call “disease-modifying” that would actually slow the progression of Alzheimer's.
As we all get older, we all have normal cognitive aging, right? We don't remember quite like we did when we were in our 20s and 30s. That’s expected. But sometimes, changes in our cognition can be such that we develop Alzheimer's dementia.
Until now, we only had medications that might help treat some of the symptoms of dementia, helping optimize our cognition or aid the memory just a little bit – but no medication that would slow down the progress of Alzheimer's dementia.
How does the drug work?
By removing a sticky protein from the brain that we believe causes Alzheimer’s to progress. Subjects in the research trials showed a modest slowing down of worsening cognition.
We're still learning a lot about dementia, and specifically Alzheimer's dementia. There is growing thought that a compound called amyloid plaque, or beta amyloid plaques, are associated with Alzheimer's disease and might even be causative of some of its neurological changes. Now, we have a medication that can address that. Leqembi actually directly targets beta amyloid.
People who have Alzheimer's disease have these beta amyloid plaques that deposit in the brain. And though amyloid is present in all brains, when it deposits in the wrong places, we think that’s what can cause Alzheimer's.
Now, this is different from the plaque that can build up in the arteries. It's a type of plaque that's only present in the brain. When we're trying to diagnose people who may have Alzheimer's, we can do brain scans that look specifically for this amyloid plaque. And the drug reduces the plaque and slows the spread of Alzheimer's.
Leqembi is not a pill; it’s more involved than just swallowing a tablet. It’s an IV infusion. And a patient will have to go to an infusion center and be there for a few hours at a time, every other week.
Does Leqembi remove the plaque buildup – those deposits you were referring to?
It appears to. During research trials, investigators looked at brain scans and saw that people with Alzheimer’s had this amyloid plaque – an abnormal buildup. After the infusion of this medication, they repeated the scans and looked for this specific protein. And in many cases, they saw fewer amyloid deposits.
We're still learning about exactly what happens in the brain with the amyloid, but we know this medication can slow down the progression of dementia and, hopefully, allow people to remain independent for as long as possible.
How do doctors know if a patient might benefit from Leqembi?
There’s an initial test to determine amyloid levels in their brain. If they’re determined to be an amount that could benefit from the drug, the patient may be eligible. Once treatment is underway, a patient will have brain scans from time to time to look for evidence of side effects.
Speaking of, what are the potential side effects?
They can be significant. Bleeding and swelling of the brain are among them.
The most common side effects, which occurred in a little more than a fourth of participants, were mild to moderate and were related to the infusion – chills, fever, body aches and a rash. And 75% of people who experienced those reactions had them after the first dose only.
Fluid formation on the brain occurred in about 12% of trial participants. They didn’t typically experience symptoms, but the condition can be detected with an MRI.
The drug label includes warnings about brain swelling and bleeding and indicates that people with a gene mutation that increases their risk of Alzheimer’s are at increased risk of brain swelling as a result of being on the drug. Furthermore, patients shouldn’t take blood thinners while on Leqembi.
Who’s a good candidate for Leqembi?
It’s not right for everyone who shows signs of Alzheimer’s. It's really targeted to people who have mild cognitive impairment or very early dementia. That means they’re not yet at a point where it's supremely affecting their daily living.
Someone who’s just beyond the point of, you know, losing their keys or forgetting the name of someone they haven't talked to in a while – that’s a good candidate.
Unfortunately, this medication is not a cure. We're not able to reverse dementia, but the hope is that if we can give this medication to people at the very earliest stages of dementia or cognitive impairment, we'll be able to slow that process down and maximize the time they're able to remain independent.
And there are a lot of patients we think could benefit from learning about this medication for the future, for their family, for their parents, for their loved ones.
What should someone do who wants to investigate use of this drug for themselves?
If I were concerned about my memory, I would talk with my primary care doctor and ask: Could the medications I'm currently on be causing this? Could anxiety or depression or stress lead to more trouble with my memory?
If your primary care doctor is concerned, they’ll refer you to a neurologist, who will ask similar questions. They can do a cognitive screen to figure out some objective measures of how your cognition actually is.
I recently heard a story on NPR about an even newer Alzheimer’s drug that’s showing early promise.
Yes, that’s donanemab, and the trial results were just announced. It’s a medication in the same category as lecanemab and has a similar mechanism of action. They have recently presented and published Phase 3 trials, which we’ve been very excited to review. Donanemab is now being reviewed by the FDA for approval. We are optimistic about the game-changing effects both lecanemab and donanemab will have and hope they will lead to better quality of life for patients and caregivers.