Antiamyloid Monoclonal Antibody Therapy Protocol

Patient Selection and Eligibility Criteria

• The American College of Radiology recommends that treatment must be initiated in patients with mild cognitive impairment or mild dementia stage of Alzheimer's disease, with mandatory baseline brain MRI screening and regular MRI monitoring for amyloid-related imaging abnormalities (ARIA) 1
• Patients with moderate or advanced dementia are not candidates for these therapies, as specified by the FDA approvals and clinical trials 1

Mandatory Biomarker Confirmation

• Blood-based biomarkers, such as plasma p-tau217, can confirm amyloid pathology with high accuracy (AUC 0.92-0.98) and are sufficient evidence without requiring additional amyloid PET, according to Nature Reviews Neurology 2
• Amyloid PET imaging can also demonstrate amyloid burden, with Centiloid values above 30 CL corresponding to pathological amyloid levels, as recommended by Praxis Medical Insights 1

Pre-Treatment Imaging Requirements

• The Journal of the American College of Radiology recommends obtaining brain MRI without IV contrast on a 3T scanner to screen for contraindications before initiating therapy, including macrohemorrhages, multiple microhemorrhages, superficial siderosis, significant vasogenic edema, and extensive white matter hyperintensities 3, 1, 4

Dosing Protocols

• Lecanemab should be administered at a dose of 10 mg/kg intravenous infusion every 2 weeks, with ongoing therapy required, as recommended by Praxis Medical Insights 1

Mandatory MRI Monitoring During Treatment

• The Journal of the American College of Radiology recommends that only MRI can detect ARIA, and that MRI monitoring is required to detect ARIA-E (edema) and ARIA-H (microhemorrhages/superficial siderosis) 3
• ARIA-E occurs in 12.6-35.2% of treated patients, with 72.7% of initial events occurring within the first 8 doses, as reported by Praxis Medical Insights 1

Clinical Efficacy Expectations

• Both lecanemab and donanemab demonstrate approximately 30% slowing of cognitive decline in early Alzheimer's disease, with clinical benefit being modest but statistically significant on CDR-SB (Clinical Dementia Rating-Sum of Boxes), as recommended by Praxis Medical Insights 1

Critical Implementation Pitfalls to Avoid

• The Journal of the American College of Radiology recommends avoiding common errors, such as initiating treatment without baseline MRI screening, skipping APOE ε4 testing, using CT instead of MRI for ARIA monitoring, treating patients beyond mild dementia stage, and failing to obtain scheduled monitoring MRIs 3, 1