Real world clinical practice of lecanemab at PUMCH dementia cohort: focus on dynamic imaging and biomarker evolution.

BACKGROUND: Lecanemab is an anti-Aβ antibody approved in China for mild cognitive impairment (MCI) and mild dementia. Real-world application requires comprehensive assessment beyond MMSE scores, considering factors like ARIA risk. This single-center, real-world study aims to evaluate its efficacy in an expanded population, observe biomarker changes, and assess its safety profile in clinical practice. METHODS: We recruited adults aged 40-90 with early AD from the PUMCH Dementia Cohort. A total of 42 patients received lecanemab treatment, of whom 29 completed the 6-month treatment evaluation. Participants had confirmed amyloid and tau pathology and met clinical criteria (CDR ≤ 1, CDR-SB ≤ 8and MMSE ≥ 18). Comprehensive assessments included neuropsychological testing, CSF and plasma biomarkers (Lumipulse G1200), multi-sequence 3T MRI (volumetric and ALPS index analysis), and amyloid/tau PET imaging (Centiloid quantification). All were monitored for adverse reactions. Matched control groups (matched for sex, age, APOE genotype, disease severity, and baseline therapy) were established for comparison of longitudinally changes in cognitive function, daily living ability and structure MRI. RESULTS: Treatment was effective even for patients with lower MMSE scores but still classified as having mild dementia by CDR. A significant median Centiloid reduction of 30.9 was observed, with a 24.1% amyloid PET negativity rate after six months. While scores on cognitive and functional scales (CDR-SB, ADL) significantly worsened, indicating disease progression, the rate of progression was significantly slower compared to the control group. Structural MRI showed significant volume reduction in multiple brain regions and increased ventricular volume post-treatment, with no statistically significant change in the ALPS value. The rate of brain volume reduction is faster than that in the control group. Plasma biomarker dynamics (Aβ42, GFAP) indicated effective disease-modifying therapy. Greater Centiloid reduction was linked to more brain volume loss, higher baseline Centiloid levels, higher plasma Aβ42 increase and older age of onset. APOE ɛ4 homozygotes showed less Centiloid reduction. A favorable safety profile was observed, with a 7.1% incidence of asymptomatic, mild ARIA. CONCLUSIONS: This study confirms the clinical efficacy, biomarker changes, and safety profile of lecanemab treatment over a 6-month period, demonstrating its positive therapeutic value and a favorable safety profile in the Chinese population with AD.