Key takeaways:
Lecanemab (Leqembi) is an injectable medication that treats mild stages of Alzheimer’s disease. It aims to slow down disease progression by targeting protein clusters called beta-amyloid plaques.
In a phase 3 clinical trial, Alzheimer’s drug lecanemab helped lower the risk of mental decline by an average of 27% compared to placebo (an injection with no medication in it).
There are many ways to save on lecanemab. If you’re eligible, a manufacturer savings card can help you access lecanemab for as little as $0 per month. A patient assistance program also exists, and a temporary supply program can help you receive free medication if you’re waiting for your insurance to approve coverage for lecanemab.
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Finding the best treatment for Alzheimer’s disease is an ongoing process. For many years, Alzheimer’s medications treated the condition by managing symptoms alone. They didn’t treat any root causes of Alzheimer’s disease itself.
In June 2021, this changed. The FDA approved Aduhelm (aducanumab-avwa), the first medication to treat one of Alzheimer’s’ underlying disease processes. It’s thought to work by interfering with protein clusters in the brain called beta-amyloid plaques.
Fast-forward to January 2023, when a second Alzheimer’s-fighting medication obtained accelerated approval — a type of FDA approval based on relatively preliminary data. It’s called lecanemab-irmb (Leqembi). The medication won full approval in July 2023, and it’s now available for use.
What is lecanemab?
Lecanemab is an injectable biologic medication that’s approved to treat Alzheimer’s disease. It aims to prevent the condition from getting worse in people living with symptoms of mild dementia or mild cognitive impairment.
However, not everybody who falls into this category is eligible for lecanemab. Your healthcare provider will need to perform tests to confirm if beta-amyloid plaques are present in your brain. The medication attacks these plaques, so if you don’t have any, lecanemab won’t be useful.
At this time, lecanemab is only approved for mild stages of Alzheimer’s disease. There currently isn’t any data to suggest it's effective for more severe stages.
How does lecanemab work to treat Alzheimer’s disease?
Health experts are actively researching ways that Alzheimer’s disease affects the brain. There’s evidence that suggests that a buildup of beta-amyloid proteins (plaques) between nerve cells in the brain can contribute to Alzheimer’s disease. This buildup can disrupt how your brain cells communicate with each other.
What’s more, the severity of the condition has been connected to how widespread these plaques are. In milder stages of Alzheimer’s disease, these plaques cover smaller regions of the brain. This can interfere with functions like memory and learning. When these plaques spread, it can contribute to cognitive changes like confusion, speech issues, and worsening behavior.
The earlier these plaques are stopped in their tracks, the better. This is what lecanemab aims to do. It helps attack and reduce further buildup of beta-amyloid plaques. It’s not a cure for Alzheimer’s disease, but it may delay dementia symptoms from worsening.
How is lecanemab dosed?
Lecanemab is administered as an intravenous (IV) infusion every 2 weeks (14 days). Each time you receive it, the medication will take about 1 hour to infuse into your body.
Since it’s an IV injection, you won’t be able to give the medication to yourself. Your healthcare provider will administer lecanemab at a hospital or infusion center. They’ll calculate your dose based on your body weight. The recommended dosage is 10 mg per kg body weight. For example, if you weigh 80 kg (176 lbs), you’ll likely receive 800 mg of medication every 2 weeks.
Understandably, it can be tough to schedule an infusion appointment every 2 weeks without any variation. If you miss a dose, try to get it as soon as you can.
How effective is lecanemab?
Initially, what we knew about lecanemab’s effectiveness came from a phase 2 clinical trial. Phase 2 clinical trials are meant to determine whether a medication works in at least a few hundred participants.
In this trial, over 800 people with mild Alzheimer’s disease were given either lecanemab or placebo (an infusion with no medication in it). After 18 months (1.5 years) of consistent use, lecanemab reduced beta-amyloid levels. People receiving placebo didn’t see any reduction. These results lead to the FDA’s accelerated approval of lecanemab.
What’s more, in a phase 3 trial that aimed to confirm lecanemab’s clinical benefits, the medication reduced the likelihood of progressing to the next stage of Alzheimer's disease by an average of 27% over an 18-month period. A panel of FDA expert advisors reviewed the data from this study, and they recommended that the agency fully approve the medication.
How does lecanemab compare to Aduhelm?
Aduhelm and lecanemab are often mentioned in the same conversation. They’re similar medications, but they haven’t been directly compared in clinical studies. So we can’t assume one is better than the other. But there are still some similarities and differences to keep in mind.
Approved use | Treating Alzheimer’s disease in people living with mild cognitive impairment or mild dementia | Same as lecanemab |
Medication type | IV infusion | IV infusion |
Dosage frequency | Every 2 weeks | Every 4 weeks |
Clinical effectiveness data is available | Yes | |
Brain-related side effects | Less common | More common |
Manufacturer | Biogen, Eisai | Biogen, Eisai |
If you’re curious if lecanemab or Aduhelm would be a better option for you, it’s important to loop in your healthcare provider. Research will continue to come out about both medications, so they can help you weigh the pros and cons of each option in real time.
What are the known side effects of lecanemab? [Side effects]
Lecanemab’s most notable side effect is ARIA (amyloid-related imaging abnormalities). More specifically, the concern is with ARIA-E and ARIA-H. ARIA-E is a type of fluid buildup in the brain. ARIA-H refers to small bleeds near the surface of the brain. ARIA doesn’t usually cause noticeable symptoms, but some people report short-term effects like dizziness, confusion, and balance problems. The FDA even issued a boxed warning about ARIA from Leqembi — the most serious type of medication warning.
ARIA isn’t thought to be a long-term problem, but your healthcare provider may delay or stop your lecanemab infusions if a routine MRI shows signs of ARIA. ARIA is more likely to happen during the first 14 weeks (3.5 months) of treatment. In most cases, ARIA resolves on its own.
Other possible lecanemab side effects include:
Infusion-related reactions, including temporary flu-like symptoms, blood pressure changes, and nausea
Headache
Cough
Diarrhea
Serious risks and side effects are rare, but possible. Three deaths have been potentially linked to lecanemab in clinical trials so far. Heart problems, including new or worsening atrial fibrillation, have also been reported.
Certain people may be more likely to develop serious side effects from lecanemab, such as potentially serious brain bleeds related to ARIA. These side effects may be more likely for people:
Taking blood thinners
With two copies of a gene called APOE4
With a brain condition called cerebral amyloid angiopathy
Does lecanemab interact with other medications?
We don’t know for sure. Lecanemab’s manufacturer hasn’t officially reported any drug interactions. As more studies take place, health experts will learn more about potential lecanemab interactions.
How to save on lecanemab
There are ways to save on lecanemab, which is only available as a reference (“brand-name”) medication. It should largely be covered by Medicare, but GoodRx can also help you navigate between patient assistance programs and copay savings cards to save money on your prescription.
Save with patient assistance programs. If you’re uninsured or underinsured, you may be eligible for lecanemab’s patient assistance program, which offers the medication free of charge.
Save with a copay savings card. If you have commercial insurance, you may be eligible to pay as little as $0 for lecanemab using a savings card from the manufacturer.
What’s more, lecanemab’s manufacturer is also offering a temporary supply program. If you have commercial insurance and you’ve been waiting at least 5 business days for your insurer to make an approval decision, you may be able to receive up to 75 days of free medication. Call 1-833-453-7362 for details.
The bottom line
Lecanemab, also known as Leqembi, is an IV medication that’s approved to treat early stages of Alzheimer’s disease. It works by targeting beta-amyloid plaques in the brain, helping fight a possible root cause of the condition. However, it can cause some side effects, including ARIA, infusion reactions, and headaches. Your healthcare provider can tell you if you or a loved one are eligible to receive Alzheimer’s drug lecanemab.
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References
Biogen. (2022). Aduhelm- aducanumab injection, solution [package insert].
Biogen. (2023). FDA approves leqembi (lecanemab-irmb) under the accelerated approval pathway for the treatment of alzheimer's disease.
ClinicalTrials.gov. (2023). A study to confirm safety and efficacy of lecanemab in participants with early alzheimer's disease (Clarity AD). U.S. National Library of Medicine.
Eisai, Inc. (2023). Leqembi injection, for intravenous use [package insert].
George, J. (2023). Alzheimer's drug clears major hurdle toward full approval. MedPage Today.
Kimball, S. (2023). FDA approves alzheimer’s drug leqembi, paving way for broader Medicare coverage. MSN.
Leo, L., et al. (2023). Eisai-Biogen alzheimer's drug data confirms benefits, FDA staff says. Reuters.
MedlinePlus. (2022). Cerebral amyloid angiopathy.
National Institute on Aging. (2017). What happens to the brain in alzheimer's disease?
National Institute on Aging. (2021). Study reveals how APOE4 gene may increase risk for dementia.
U.S. Food and Drug Administration. (2023). FDA converts novel alzheimer’s disease treatment to traditional approval.
U.S. Food and Drug Administration. (2023). FDA grants accelerated approval for alzheimer’s disease treatment.
Woloshin, S., et al. (2022). What to know about the alzheimer drug aducanumab (aduhelm). JAMA Internal Medicine.
