Wang Liao, Qun Yu, Bin Chen, Hualin Chen, Liangyu Zou, Haiqun Xie, Haobo Chen, Chenyang Wang, Yiming Li, Xiaoya Gao, Hongbo Guo, Ying Yang, Ziyu She, Qinggan Zeng, Zengqiang Zhang, Guihua Li, Shujun Feng, Han Lin, Jipeng Ouyang, Junyan Liang, Wenling Ao, Qiong Zeng, Yang Liu, Hanyu Weng, Hongqiang Huang, Feiqi Zhu, Runni Liu, Yingte Wang, Dapeng Yu, Xue Li, Yingren Mai, Shengnan Jiang, Yu Tu, Zhiming Li, Jun Liu, for the Alzheimer's Disease Neuroimaging Initiative
BACKGROUND: Lecanemab, an anti-amyloid beta (Aβ) protofibril antibody, was introduced in China in 2024, but its real-world performance remains unknown. METHODS: In this prospective, multicenter study across 21 sites, 261 Alzheimer's disease patients (mild cognitive impairment to moderate dementia) received biweekly lecanemab (10 mg/kg). A matched Alzheimer's Disease Neuroimaging Initiative (ADNI) cohort served as comparator. Cognitive tests, plasma biomarkers, and optional amyloid/tau positron emission tomography (PET) were assessed over 6 months. RESULTS: Lecanemab significantly attenuated cognitive decline versus ADNI. Plasma Aβ42, Aβ40, phosphorylated tau 217 (p‑tau217), glial fibrillary acidic protein (GFAP), and ratios showed robust changes; a p‑tau217 reduction correlated with amyloid PET clearance (mean -22.1 Centiloid; 29.2% turned amyloid-negative). Apolipoprotein E (APOE) ε4 non-carriers showed greater improvements. Infusion reactions occurred in 11.1% and amyloid-related imaging abnormalities in 9.2% (1.6% symptomatic), with no stage-related safety differences. CONCLUSION: Lecanemab was effective and well tolerated in real-world Chinese patients. Plasma p‑tau217 may serve as a sensitive, minimally invasive treatment-response biomarker.