What is lecanemab?

Lecanumab is a monoclonal antibody developed by Biogen through partnership with Eisai pharmacuticals that removes a protein called beta-amyloid from the brain. It is infused through a vein for about 1 hour every two weeks for a total of 18 months.

Patients with Alzheimer’s disease have a build-up of the proteins, beta-amyloid and tau in their brain. The accumulation of these proteins is thought to result in the degeneration of neurons and the associated cognitive decline. With the help of your immune system, lecanumab selectively targets and removes the beta-amyloid from the brain.

Lecanemab Phase 3 Trial: Clarity

Lecanemab slows cognitive decline in patients with Alzheimer’s disease

Commentary

Lecanemab slows cognitive decline (as detected by the ADAS-Cog14) and activities of daily living (as detected by the CDR-SB) over the course of 18 months by about 30%. Whether this slower rate of decline is permanent or worsens after stopping lecenemab is not known.

Only patients with Mild Cognitive Impairment or Early Dementia from Alzheimer’s Disease were enrolled in this study.

Lecanemab removes amyloid from the brain

Commentary

There is no evidence that those patients with the most amyloid removed had the most benefit clinically. We do not know the significance of the amyloid removal.

Which patients benefit the most from lecanemab?

Commentary

Male patients, ApoE4 noncarriers, and patients older than 75 responded better to lecanemab.

Conversely ApoE4 carriers and patients younger than 65 did not respond as well to lecanemab.

African Americans/Blacks had a highly variable response to lecanemab.

Adverse Events

Commentary

The most concerning side effect was ARIA – Amyloid Related Imaging Abnormalities. This is either swelling (ARIA-E) or bleeding (ARIA-H) in the brain.

13% of patients receiving lecanemab will develop ARIA-E and about 1/5 of these patients will have symptomatic ARIA-E requiring stopping lecenemab. Symptoms include headaches, visual problems, and confusion.

17% of patients will develop ARIA-H and only 4/100 will have symptomatic ARIA-H requiring stopping lecanemab. Most common symptom was dizziness.

There have been 2 fatalities from brain bleeding. One patient was taking an oral anticoagulant and the second patient had a stroke and received TPA, a clot busting agent.

And there has been 1 fatality from brain swelling and edema in patients who received lecanumab.

FAQs

What is lecanemab?

Lecanumab is a monoclonal antibody developed by Biogen through partnership with Eisai pharmacuticals that removes a protein called beta-amyloid from the brain. It is infused through a vein every two weeks.

How does lecanemab work? 

Patients with Alzheimer’s disease have a build-up of the proteins, beta-amyloid and tau in their brain. The accumulation of these proteins is thought to result in the degeneration of neurons and the associated cognitive decline. With the help of your immune system, lecanumab selectively targets and removes the beta-amyloid from the brain.

How much does lecanemab cost?  

Lecanumab will cost $26,500 annually. Additional costs such as, but not limited to, amyloid PET and MRI scans and related blood tests are not included in the cost.

When will lecanumab be available?  

The FDA has announced that lecanemab’s prescription drug user fee act action date is July 6, 2023. If FDA grants traditional approval, CMS has already announced that they will cover anti-amyloid monoclonal antibodies therapies (lecanemab), which are approved by the FDA, on the same day the FDA grants traditional approval. The CMS will require all patients receiving lecanemab be enrolled in a clinical registry. We are working to ensure that lecanumab will then be available to patients at the BIDMC once the FDA and CMS grant traditional approval. The CNU, BIDMC, and the BI-Lahey system are working together to ensure that the medication can be delivered as safely and effectively as possible to eligible patients when available. 

Who is eligible to receive lecanemab?  

Lecanumab was shown to be effective in the treatment of mild cognitive impairment or mild dementia stage of disease caused by Alzheimer’s. There is no evidence that it would be effective in the treatment of other types of diseases or in later stages of Alzheimer’s disease. Patients with mild cognitive impairment or mild dementia from Alzheimer’s disease with confirmed amyloid pathology, through either a lumbar puncture or amyloid beta positron emission tomography (PET) scan of the brain, will be eligible.

What are some potential risks of lecanemab?

Patients who receive lecanumab are at risk for developing a kind of brain inflammation called amyloid-related imaging abnormalities (ARIA), which involves brain bleeding, brain swelling, or a combination of the two. A few of these will need to discontinue their treatment due to concerns related to ARIA. Before and after lecanumab is started, patients must receive special monitoring (including brain MRI scans) to screen for ARIA.

There have been 2 fatalities from brain bleeds and 1 fatality from brain swelling and edema in patients who received lecanumab.

What if I am enrolled in a clinical trial?  

We would encourage you to continue participation in ongoing clinical trials. If you have any questions or concerns about how starting aducanumab may impact your continued participation in the clinical trial, please discuss them with the principal investigator of your clinical trial or your physician.

Next steps at BIDMC

The BI-Lahey Pharmacy and Therapeutics Committee has voted to add lecanumab to our formulary. Our team will keep this webpage up to date with information about our lecanumab program as it develops, and we will update patients through our Memory A2Z clinic email list (see above for instructions on getting added to this list). We will also include updated educational materials as they become available.

If you or your loved one is worried about new and progressive concerns with memory, language or behavior, the first best step is to consult with a doctor and specifically consider a referral to a neurologist. If you are specifically interested in receiving diagnostic assessment and care at BIDMC, please contact the BIDMC Cognitive Neurology Unit at 617-667-4074.