You may qualify for Leqembi or Kisunla if you have early Alzheimer's disease — meaning mild cognitive impairment or mild dementia — and a brain scan or spinal fluid test confirms you have amyloid buildup. You will not qualify if your dementia has reached the moderate or severe stage, or if testing shows your memory problems are not driven by Alzheimer's amyloid.
Leqembi and Kisunla are the first FDA-approved drugs shown to slow the underlying disease rather than just ease symptoms. Both are antibody infusions that clear amyloid, a sticky protein that clumps in the brain during Alzheimer's. This page explains who fits the criteria, what testing is required, and the trade-offs to weigh with a doctor.
Medical information disclaimer: This article is for general educational purposes only and does not provide medical advice, diagnosis, or treatment. Always consult a physician or other qualified health professional about symptoms, medications, tests, or treatment decisions.
Table of Contents
- The two core requirements: early stage plus confirmed amyloid
- Who does not qualify
- Genetic testing and the ARIA risk
- What the drugs actually deliver — and don't
- A practical checklist and how delivery is changing
- Frequently Asked Questions
The two core requirements: early stage plus confirmed amyloid
Eligibility for both drugs rests on two things. First, you must be at the **early symptomatic stage** — either mild cognitive impairment (MCI, subtle memory or thinking changes that don't yet disrupt daily life) or mild dementia. Second, a test must confirm that amyloid plaque is actually present in your brain. That second step is not optional.
Doctors confirm amyloid with a **PET scan** (a specialized brain image) or a **cerebrospinal fluid test** (a sample drawn by lumbar puncture). Newer blood tests are emerging but are used alongside, not in place of, these confirmatory methods. These criteria mirror the patients studied in the approval trials. According to the FDA's approval of Leqembi, the drug is indicated for early Alzheimer's with confirmed elevated beta-amyloid; Eli Lilly reports the same early-stage, amyloid-confirmed indication for Kisunla. Leqembi (lecanemab-irmb) earned full approval on July 6, 2023, and Kisunla (donanemab-azbt) followed on July 2, 2024.
Who does not qualify
The same rules that define eligibility also rule people out. If Alzheimer's has advanced to the moderate or severe stage, neither drug is approved for you, because the trials did not study those patients and the benefit was not established there.
You also will not qualify if your cognitive symptoms stem from something other than Alzheimer's amyloid — for example, vascular dementia or Lewy body disease without confirmed amyloid. This is exactly why the biomarker test matters: a clinical memory diagnosis alone is not enough. Certain medical factors can also exclude or delay treatment, such as being on blood thinners or having a history of significant brain bleeding, which raise the risk of the side effects covered below.
Genetic testing and the ARIA risk
Before starting either drug, labels recommend a genetic test for **APOE ε4**, a gene variant that affects your risk of the most serious side effect. Both carry an FDA **Boxed Warning for ARIA** — amyloid-related imaging abnormalities, meaning brain swelling or small bleeds that show up on MRI. The Leqembi safety information details this warning and the genotype recommendation.
Your APOE ε4 status changes the risk math. According to NCBI's Medical Genetics Summaries, people who carry two copies of ε4 (homozygotes) developed brain swelling in about 45% of cases on Leqembi, versus roughly 13% in non-carriers. Testing is recommended but not mandatory. Its purpose is informed counseling: a high-risk result doesn't automatically disqualify you, but it should shape a frank conversation about whether the benefit outweighs the danger for you specifically.
What the drugs actually deliver — and don't
These drugs slow decline; they do not stop, cure, or reverse Alzheimer's. In the Phase 3 CLARITY AD trial of 1,795 patients, Leqembi slowed cognitive and functional decline by 27% over 18 months compared with placebo. Kisunla's TRAILBLAZER-ALZ 2 trial slowed decline by about 35% at 76 weeks in patients with low-to-medium tau, though ARIA occurred in roughly 24% of treated patients, mostly without symptoms. It helps to translate that.
A 27% to 35% slowing means the disease still progresses — just more slowly. For some families that extra time holding onto independence is meaningful; for others it may not justify the burden and risk. The Alzheimer's Association's overview frames these as disease-slowing, not curative. Both require ongoing commitment. Treatment involves regular infusions plus **serial MRI scans** to monitor for ARIA, so eligibility also depends on access to that monitoring infrastructure.
A practical checklist and how delivery is changing
Use this as a quick self-check before a specialist visit: Delivery options are expanding. The FDA has approved an at-home subcutaneous starting dose for Leqembi with IV maintenance, and Kisunla's label was updated with a revised titration schedule designed to lower the chance of brain swelling. For the current indication and eligibility language, the Leqembi prescribing information is the primary reference to review with your doctor.
- **Stage:** Are symptoms still mild (MCI or mild dementia), not moderate or severe?
- **Confirmation:** Has a PET scan or spinal fluid test confirmed amyloid?
- **Genetics:** Have you discussed APOE ε4 testing and your ARIA risk?
- **Monitoring:** Can you commit to repeat infusions and follow-up MRIs?
- **Other risks:** Do blood thinners or prior brain bleeds apply to you?
Frequently Asked Questions
Can I start treatment based on a memory-clinic diagnosis alone?
No. Both drugs require biomarker proof of amyloid from a PET scan or spinal fluid test, not just a clinical diagnosis of Alzheimer's.
Does a high-risk APOE ε4 result automatically disqualify me?
No. Testing is recommended for counseling, not as a hard cutoff, but two copies of ε4 sharply raise ARIA risk and should factor into the decision.
Will these drugs restore memory I've already lost?
No. They slow decline by roughly 27% to 35% in trials but do not reverse damage or cure the disease.
