What are the contraindications for starting Lecanemab (generic name) in patients with early Alzheimer's Disease (AD)?

Contraindications for Starting Lecanemab in Early Alzheimer's Disease

Lecanemab is contraindicated in patients with serious hypersensitivity to lecanemab-irmb or to any of the excipients of LEQEMBI, with reactions including angioedema and anaphylaxis. 1

Primary Contraindications

• Serious hypersensitivity to lecanemab-irmb or any excipients in the formulation 1
• History of angioedema or anaphylaxis related to lecanemab or similar medications 1

Risk Factors Requiring Careful Evaluation

Amyloid-Related Imaging Abnormalities (ARIA) Risk Factors

• ApoE ε4 homozygous status - these patients have significantly higher risk of severe ARIA-E (5%) and severe ARIA-H (13.5%) compared to heterozygotes or non-carriers 1
• Current use of anticoagulant therapy - associated with increased risk of intracerebral hemorrhage 2
• Use of tissue plasminogen activator - associated with increased risk of intracerebral hemorrhage 2

Contraindications for Lumbar Puncture (if CSF biomarkers are being used)

• Use of anticoagulant medications 3
• Blood clotting disorders 3
• Recent seizures 3
• Intracranial lesions associated with increased intracranial pressure 3
• Papilledema 3
• Impaired consciousness 3

Monitoring Requirements

• Baseline brain MRI is required before initiating treatment 1
• Enhanced clinical vigilance for ARIA is necessary during the first 14 weeks of treatment 1
• Regular MRI monitoring is required throughout treatment 1
• Ability to comply with monitoring protocols is essential 1, 2

Clinical Considerations

• Lecanemab is specifically indicated for early Alzheimer's disease (mild cognitive impairment or mild dementia due to AD) with confirmed amyloid pathology 4
• Treatment should not be initiated in patients with moderate to severe dementia as efficacy has not been established in these populations 4
• Patients must be able to tolerate intravenous infusions, as infusion-related reactions occur in approximately 26% of patients 1, 2

Common Adverse Events to Consider

• Infusion-related reactions (26.4% of patients) - including fever, flu-like symptoms, nausea, vomiting, and blood pressure changes 1, 2
• ARIA-E (edema) occurs in approximately 13.6% of patients 2
• ARIA-H (microhemorrhages) occurs in approximately 16% of patients 2
• Transient decreased lymphocyte counts and increased neutrophil counts may occur after infusion 1

Practical Approach to Patient Selection

1. Confirm early Alzheimer's disease diagnosis (MCI or mild dementia) with evidence of amyloid pathology 4
2. Screen for contraindications, particularly hypersensitivity to lecanemab 1
3. Assess ApoE ε4 status to determine ARIA risk 1
4. Evaluate concurrent medications, particularly anticoagulants 2
5. Confirm ability to comply with required MRI monitoring 1
6. Ensure appropriate resources for managing potential adverse events 2, 5

When considering lecanemab treatment, the risk-benefit profile must be carefully evaluated for each patient, with particular attention to the risk of ARIA in ApoE ε4 homozygotes and patients on anticoagulation therapy 1, 2.