Treatments

Lecanemab (Leqembi)

Lecanemab is one of the first FDA-approved infusions that clears amyloid plaques from the brain. It's not a cure — it slows decline modestly in early Alzheimer's.

Updated 2026-02-15

How it works

Lecanemab is a monoclonal antibody. Given by IV every two weeks, it sticks to amyloid plaques and signals the immune system to clear them. Clinical trials showed roughly 27% slower decline over 18 months in early-stage Alzheimer's.

Who qualifies

  • Confirmed early-stage Alzheimer's (mild cognitive impairment or mild dementia).
  • Amyloid biomarker positive — either PET scan or cerebrospinal fluid result.
  • No history of recent stroke, brain bleed, or active anticoagulation in some clinics.
  • Able to attend infusions every two weeks and tolerate frequent MRIs.

Side effects to know

  • ARIA — amyloid-related imaging abnormalities. Roughly 12–17% of patients show brain swelling or microbleeds on MRI. Most cases are mild and symptom-free; some are serious.
  • Higher risk for people with two copies of the APOE-ε4 gene.
  • Infusion reactions — chills, nausea, headache — usually first dose.

Frequently asked questions

Does Medicare cover Leqembi?
Yes — Medicare Part B covers it for eligible patients with amyloid confirmation and ongoing safety monitoring.
Is Donanemab the same?
Different drug, same class (anti-amyloid). Donanemab (Kisunla) is monthly and stops once amyloid is cleared. Roughly similar slowing of decline.
Will my mom recognize me longer if she takes it?
Possibly — the slower decline is real but modest. Most families report subtle stability rather than dramatic improvement.

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