Alzheimer's disease

Last reviewed: 31 Dec 2022
Last updated: 13 Dec 2022
13 Dec 2022

Lecanemab slows cognitive decline in patients with early Alzheimer's disease

Lecanemab is a humanised monoclonal antibody that binds with high affinity to amyloid-beta. In a multicentre, double-blind, phase 3 trial involving people aged 50 to 90 years with early Alzheimer's disease (defined as mild cognitive impairment or mild dementia due to Alzheimer's disease), intravenous lecanemab was associated with moderately less decline in cognition and function, as well as reduced brain amyloid burden, at 18 months, compared with placebo. Adverse effects of lecanemab included infusion-related reactions and amyloid-related imaging abnormalities with oedema or effusions.[200]

Applications for US FDA approval of intravenous lecanemab, and marketing authorisations in Japan and Europe, are expected to be considered in 2023.

Further studies of lecanemab are ongoing, including a phase 1 study investigating subcutaneous dosing.

See Management: emerging

Original source of update



History and exam

Key diagnostic factors

  • presence of risk factors
  • memory loss
  • disorientation
  • nominal dysphasia
  • misplacing items/getting lost
  • apathy
  • decline in activities of daily living and instrumental activities of daily living (IADLs)
  • personality change
  • unremarkable initial physical examination
More key diagnostic factors

Other diagnostic factors

  • mood changes
  • poor abstract thinking
  • constructional dyspraxia
  • prosopagnosia
  • autoprosopagnosia
Other diagnostic factors

Risk factors

  • advanced age
  • family history
  • genetics
  • Down's syndrome
  • cerebrovascular disease
  • lifestyle factors and medications
  • less than secondary school education
  • traumatic brain injury
  • depression
  • hearing loss
  • hyperlipidaemia
  • female sex
  • elevated plasma homocysteine level
  • artificially sweetened soft drink consumption
More risk factors

Diagnostic investigations

1st investigations to order

  • bedside cognitive testing
  • FBC
  • metabolic panel
  • serum thyroid-stimulating hormone (TSH)
  • serum vitamin B12
  • urine drug screen
  • CT
  • MRI
More 1st investigations to order

Investigations to consider

  • cerebrospinal fluid (CSF) analysis
  • serum rapid plasma reagin/Venereal Disease Research Laboratory (VDRL)
  • serum HIV
  • formal neuropsychological testing
  • genetic testing
  • fluorodeoxyglucose-PET (FDG-PET)
  • single-photon emission CT (SPECT)
  • electroencephalogram (EEG)
More investigations to consider

Emerging tests

  • amyloid-PET

Treatment algorithm


all patients



Judith Neugroschl, MD

Associate Professor of Psychiatry

Icahn School of Medicine at Mount Sinai

New York



JN declares that she has no competing interests.


Dr Judith Neugroschl would like to gratefully acknowledge Dr Brandy R. Matthews, Dr Asif S. Bhutto, and Dr Julie K. Gammack, the previous contributors to this topic.


BRM, ASB, and JKG declare that they have no competing interests.

Peer reviewers

Roy J. Goldberg, MD, FACP, AGSF, CMD

Medical Director

Kings Harbor Multicare Center

New York



RJG declares that he has no competing interests.

Philip Scheltens, MD, PhD

Professor of Neurology

Department of Neurology/Alzheimer Center

VU University Medical Center


The Netherlands


PS declares that he has no competing interests.

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