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Leqembi Side Effects

Generic name: lecanemab

Medically reviewed by Drugs.com. Last updated on Sep 1, 2023.

Note: This document contains side effect information about lecanemab. Some dosage forms listed on this page may not apply to the brand name Leqembi.

Applies to lecanemab: intravenous solution.

Warning

Intravenous route (Solution)

Warning: Amyloid Related Imaging AbnormalitiesMonoclonal antibodies directed against aggregated forms of beta amyloid, including lecanemab-irmb, can cause amyloid related imaging abnormalities (ARIA), characterized as ARIA with edema (ARIA-E) and ARIA with hemosiderin deposition (ARIA-H). Incidence and timing of ARIA vary among treatments. ARIA usually occurs early in treatment and is usually asymptomatic, although serious and life-threatening events rarely can occur. Serious intracerebral hemorrhages, some of which have been fatal, have been observed in patients treated with class of medications.ApoE e4 HomozygotesPatients who are apolipoprotein E e4 (ApoE e4) homozygotes (approximately 15% of Alzheimer's disease patients) treated with this class of medications, including lecanemab-irmb, have a higher incidence of ARIA, including symptomatic, serious, and severe radiographic ARIA, compared to heterozygotes and noncarriers. Testing for ApoE e4 status should be performed prior to initiation of treatment to inform the risk of developing ARIA. Prior to testing, prescribers should discuss with patients the risk ARIA across genotypes and the implications of genetic testing results. Prescribers should inform patients that if genotype testing is not performed they can still be treated with lecanemab-irmb; however, it cannot be determined if they are ApoE e4 homozygotes and at higher risk for ARIA.Consider the benefit of lecanemab-irmb for the treatment of Alzheimer's disease and potential risk of serious adverse events associated with ARIA when deciding to initiate treatment with lecanemab-irmb.

Serious side effects of Leqembi

Along with its needed effects, lecanemab (the active ingredient contained in Leqembi) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur while taking lecanemab:

More common

Less common

Incidence not known

For Healthcare Professionals

Applies to lecanemab: intravenous solution.

General

The most common adverse reactions reported were infusion-related reactions, headache, and amyloid related imaging abnormalities.[Ref]

Cardiovascular

Common (1% to 10%): Atrial fibrillation[Ref]

Gastrointestinal

Common (1% to 10%): Diarrhea[Ref]

Hematologic

Common (1% to 10%): Lymphopenia[Ref]

Other

Very common (10% or more): Infusion-related reactions (20%)[Ref]

Respiratory

Common (1% to 10%): Cough[Ref]

Nervous system

Very common (10% or more): Amyloid related imaging abnormalities (10%), headache (14%)[Ref]

Frequently asked questions

References

1. Product Information. Leqembi (lecanemab). Eisai Inc. 2023;1.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.