Donanemab (Kisunla)
The monthly anti-amyloid infusion for early Alzheimer's—how it works, results, ARIA risk, and the option to stop once amyloid clears.
Last reviewed: October 2026
Donanemab (brand name Kisunla) is an anti-amyloid medicine approved by the FDA in July 2024 for early Alzheimer's disease. Like Lecanemab (Leqembi), it removes amyloid plaques from the brain and modestly slows decline. Its distinctive features are a monthly infusion schedule and the possibility of stopping treatment once amyloid has been cleared.
How it works
Donanemab is a monoclonal antibody that targets a modified form of beta-amyloid found in established plaques. By binding to plaques, it signals the immune system to clear them. In trials, amyloid levels dropped quickly; many participants reached levels considered "amyloid-negative" within 6 to 12 months.
Who it's for
Donanemab is approved for people with Mild Cognitive Impairment (MCI) or mild dementia due to Alzheimer's Disease, with amyloid confirmed by PET scan or spinal fluid testing. As with lecanemab, it is not approved for later stages or other dementias, and it may not be suitable for people on blood thinners or with significant changes on brain MRI.
How well does it work?
In the TRAILBLAZER-ALZ 2 trial of about 1,700 people, published in JAMA in 2023, donanemab slowed decline over 76 weeks by about 35% on the trial's main measure of memory and daily function in people with low to intermediate levels of tau (another Alzheimer's protein), and by about 22% in the whole group. People earlier in the disease appeared to benefit more. Participants still declined, but more slowly. Some reported outcomes, such as the risk of progressing to the next stage of disease, also favored donanemab.
About half of participants met criteria to switch to placebo by one year because their amyloid had cleared—and the benefit appeared to continue for the rest of the trial. This "treat to clearance" approach can reduce the number of infusions and total cost.
Side effects: ARIA
Like other anti-amyloid drugs, donanemab can cause ARIA:
- ARIA-E (brain swelling) occurred in about 24% of participants in the trial.
- ARIA-H (small bleeds or iron deposits) occurred in about 31%.
Most cases had no symptoms and were found on MRI, but some caused headache, confusion, nausea, vision changes or seizures. In the trial, serious ARIA occurred in a small percentage of people and three deaths were attributed to it. Risk is highest for people with two copies of APOE4, and the medicine carries a boxed warning. In 2025, the FDA approved an updated label with a more gradual starting-dose schedule, which in a follow-up study (TRAILBLAZER-ALZ 6) lowered the rate of ARIA-E without reducing amyloid clearance.
Infusion reactions (chills, rash, nausea, breathing changes) can also occur.
Anyone on donanemab who develops sudden neurological symptoms should get prompt medical care and tell clinicians about the treatment.
What treatment involves
- Before starting: confirmation of amyloid, a baseline MRI, discussion of APOE testing and risks.
- Dosing: an IV infusion about every four weeks, lasting roughly 30 minutes.
- Monitoring: MRI scans at set points during the first months to check for ARIA, and more if symptoms appear.
- Stopping: doctors may stop treatment when an amyloid PET scan shows that plaques have been cleared.
Cost and coverage
The list price is high, though limited-duration treatment may lower total cost. Medicare covers donanemab for eligible people through a registry-based process, and testing, MRI and infusion costs add up. Ask the treating center and your insurer about out-of-pocket costs.
Lecanemab vs. donanemab
There are no head-to-head trials. Key differences people consider:
| Lecanemab | Donanemab | |
|---|---|---|
| Schedule | IV every 2 weeks; at-home injection option for maintenance | IV every 4 weeks |
| Duration | Ongoing | May stop when amyloid is cleared |
| ARIA-E in pivotal trial | ~13% | ~24% (lower with newer dosing) |
The best choice depends on the individual, the treatment center and personal preferences. See Dementia Treatments: An Overview.
The bottom line
Donanemab offers a modest slowing of early Alzheimer's, with a monthly schedule and the possibility of finishing treatment, but it carries a meaningful risk of ARIA. It requires a careful, informed decision with a specialist.
Sources
- Sims JR et al. Donanemab in Early Symptomatic Alzheimer Disease (TRAILBLAZER-ALZ 2). JAMA, 2023
- FDA: FDA approves treatment for adults with Alzheimer's disease (July 2024)
- Alzheimer's Association: Kisunla (donanemab)
- Rabinovici GD et al. Donanemab: Appropriate use recommendations. J Prev Alzheimers Dis, 2025
Not medical advice. This article is general information, not a diagnosis or treatment plan for any individual. Talk with a doctor about your situation.
Related articles
- Lecanemab (Leqembi)
- Dementia Treatments: An Overview
- Alzheimer's Disease
- Cholinesterase Inhibitors and Memantine
- Non-Drug Treatments for Dementia
Ask a question
Have a question about memory, Alzheimer's, or caregiving? Email us at:
Open in my email app · Write in Gmail (opens in a new tab)
We may answer common questions in future updates (we won't share your name). We can't give personal medical advice; for urgent help call the Alzheimer's Association Helpline at 800-272-3900.