Lecanemab (Anti-Amyloid Monoclonal Antibody)

How it works

It is a monoclonal antibody that preferentially binds soluble amyloid-beta protofibrils and promotes clearance of amyloid, reducing plaque burden.

Prescribing in practice

• Amyloid-related imaging abnormalities (ARIA) with cerebral oedema and microhaemorrhage are the principal safety concern, requiring baseline and follow-up MRI, with heightened risk in ApoE e4 carriers.
• Confirmation of amyloid pathology and assessment for haemorrhage risk are required before starting, with treatment given by infusion under specialist supervision.
• Concomitant anticoagulation increases the risk of serious intracerebral haemorrhage and must be carefully weighed.

Monitoring

Scheduled MRI surveillance for ARIA, together with monitoring for infusion-related reactions and clinical response, is required throughout treatment.

Counselling the patient

• You will need regular brain scans to look for swelling or small bleeds.
• Report new headache, confusion, weakness or visual disturbance without delay.
• The treatment is intended to slow decline, not cure the disease.

Evidence & guidelines

Phase 3 trial data demonstrate that lecanemab reduces amyloid and modestly slows cognitive and functional decline in early Alzheimer's disease.