How do I decide between Leqembi and Kisunla?

Leqembi (lecanemab-irmb) and Kisunla (donanemab-azbt) are two injectable treatments for Alzheimer’s disease. While both medications work by reducing amyloid plaques in the brain, there are some differences to consider when deciding between the two. These include effectiveness, side effects, and cost.

How are Leqembi and Kisunla given?

Both Leqembi and Kisunla are injected into the veins as an intravenous infusion, but they differ in terms of how often you need to receive a dose.

• Leqembi is typically infused over an hour once every 2 weeks.
• Kisunla is typically infused over 30 minutes once every 4 weeks.

With Kisunla, the infusions are shorter and you need to get them less often.

How effective are Leqembi and Kisunla?

Leqembi and Kisunla have not been studied in the same clinical trial, so it is difficult to directly compare how well they work. Each medication was studied in separate clinical trials.

Kisunla was FDA approved based on an 18-month, double-blind, placebo-controlled study called TRAILBLAZER-ALZ 2. Participants taking Kisunla had a slowing of decline up to 35% compared to placebo on the integrated Alzheimer's Disease Rating Scale (iADRS). These results suggest that Kisunla can help people with mild dementia symptoms perform better at thinking, memory, and daily functions for longer than if they did not take the medication.

Leqembi received traditional FDA approval after initially being approved under the Accelerated Approval pathway based on a phase-3 clinical trial called Clarity AD. The study showed that participants taking Leqembi had 27% slower cognitive decline at 18 months compared to placebo. Researchers used tests including the CDR-SB, ADAS-Cog14, and Alzheimer's Disease Cooperative Study-Activities of Daily Living Scale for Mild Cognitive Impairment (ADCS MCI-ADL) to assess cognition and function.

What are the side effects of Leqembi and Kisunla?

Leqembi and Kisunla have some similar and some different side effects. The safety of Kisunla was studied in over 2,800 patients and Leqembi was studied in over 2,000 patients.

The most common side effects of Leqembi reported during clinical trials included:

• Infusion-related reactions (up to 26%)
• Headache (up to 14%)
• Amyloid related imaging abnormalities with hemosiderin deposition, or ARIA-H (up to 14%)
• Amyloid related imaging abnormalities with edema, or ARIA-E (up to 13%)
• Cough (9%)
• Diarrhea (up to 8%)
• Superficial siderosis (up to 6%)
• Rash (up to 6%)
• Nausea/vomiting (up to 6%)

The most common side effects of Kisunla reported during clinical trials included:

• ARIA-H microhemorrhage (25%)
• ARIA-E (24%)
• ARIA-H superficial siderosis (15%)
• Headache (13%)
• Infusion-related reactions (9%)
• Allergic reaction (3%)

Both Leqembi and Kisunla have a risk of developing amyloid related imaging abnormalities (ARIA). People with ARIA have swelling in certain areas of the brain with or without small spots of bleeding. This usually happens early in treatment and most people do not have symptoms. Rarely, it can cause seizures and other serious problems. Symptoms of ARIA may include:

• Nausea
• Headache
• Vision changes
• Dizziness
• Trouble walking

Discuss these risks and the benefits of Leqembi and Kisunla with your healthcare provider.

What is the cost of Leqembi and Kisunla?

The cost of treatment with Leqembi and Kisunla depends on how long you need treatment. Your healthcare provider may consider stopping treatment once the amyloid plaques in your brain reach a certain level. The amount of time it takes for these medications to remove amyloid plaques is different for each person.

As of July 2024, a single 20 mL vial of Kisunla was priced at $695.65. Keep in mind that for the first three doses, you will require two vials for each treatment. After that, you will need four vials per treatment.

In early 2023, Eisai announced the wholesale price of the 200 mg vial of Leqembi would be $254.81 and $637.02 for the 500 mg vial. The usual dose is 10 mg/kg of body weight, so the price can vary depending on how much medication you need for each treatment.

Your out-of-pocket cost depends on your insurance plan. Contact your insurance to find out if Leqembi or Kisunla are covered, and how much you will be responsible for. Medicare coverage is available for both medications, but you must meet certain requirements.

This is not all the information you need to know about Leqembi (lecanemab) and Kisunla (donanemab-azbt) for safe and effective use and does not take the place of your doctor’s directions. Review the full product information and discuss this information and any questions you have with your doctor or other health care provider.