Mild cognitive impairment and early Alzheimer's disease eligibility for disease modification therapies in a tertiary centre for cognitive disorders: A simultaneous real-word study on aducanumab and lecanemab.

Background and purpose: The Food and Drug Administration approved two disease-modifying treatments (DMTs) for Alzheimer's disease (AD), aducanumab and lecanemab, with limited clinical impact but significant biomarker changes. Identifying suitable candidates for these DMTs outside randomized clinical trials (RCTs) remains uncertain.

Methods: This cross-sectional study, conducted in an Italian tertiary centre for cognitive disorders, aimed to evaluate how the RCT eligibility criteria for DMT treatments applies to participants with early AD. The broader Cummings et al. (Journal of Prevention of Alzheimer's Disease, 2021, 2023) criteria and the clinical differences between DMT candidates were also assessed.

Results: The study involved 408 participants (mean age 71.1 ± 8.5 years, 48% male) with a clinical diagnosis of mild cognitive impairment (161/408, 39.5%) or mild dementia (247/408, 60.5%). Amongst them, 169 individuals (41%) showed positive AD pathology biomarkers. Eligibility RCT assessment revealed 14 patients eligible for aducanumab (3.43% of 408) and 28 for lecanemab (6.86% of 408). Following Cummings' real-world criteria, aducanumab eligibility increased to 9.56%, whereas lecanemab eligibility rose to 8.33%. Applying selection criteria to only the amyloid positive (169 out of 408), the selection for DMTs was 8.3% for aducanumab and 16.5% for lecanemab.

Conclusion: Amongst subjects diagnosed with mild AD and mild cognitive impairment in a tertiary centre for cognitive disorders, only a small percentage of patients using RCT diagnostic criteria are eligible for DMT. The application of Cummings criteria strongly increased the DMT candidates. Nevertheless, the majority of patients with cognitive disorders have been excluded from DMTs approved so far.