As anti-amyloid therapy moves from clinical trials into everyday medical practice, the gap between controlled trial populations and real-world patients becomes critical. A large Chinese multicentre cohort now provides some of the first real-world safety and short-term efficacy data for lecanemab outside the Western populations that dominated pivotal trials — data that matter because genetic risk profiles, disease staging distributions, and healthcare monitoring infrastructure can differ substantially across populations.
Across seven hospitals in China, 407 patients received at least one lecanemab infusion and were followed for a mean of approximately 5.6 months. The cohort was notably advanced in disease burden: 83% were classified at biological Stage C, indicating established amyloid and tau pathology. APOE ε4 carriers comprised 56.5% of participants — a proportion relevant because this genotype is the dominant known risk factor for amyloid-related imaging abnormalities (ARIA). Overall, 22.2% of patients experienced treatment-related symptoms, while 12.15% developed at least one ARIA event on MRI monitoring. Severe or symptomatic ARIA events were comparatively rare, with only four symptomatic and seven severe cases recorded. Six-month cognitive and plasma biomarker assessments were conducted, with changes analyzed via linear mixed-effect models, though the absence of an untreated control group limits causal interpretation.
These figures land in a broadly comparable range to the CLARITY AD trial's ARIA incidence, though direct comparison is complicated by differences in staging and monitoring intervals. The high proportion of Stage C patients — more advanced than typical trial eligibility — is a meaningful signal: real-world prescribers appear to be extending treatment to patients who may derive less benefit or carry higher risk. The absence of a control arm means cognitive trajectory changes cannot be cleanly attributed to the drug versus natural disease progression over a short window. Still, for a field hungry for non-Western pharmacovigilance data, this 407-patient dataset is a substantive increment. The findings suggest lecanemab's safety profile is broadly consistent across this Chinese cohort, but the advanced staging distribution warrants monitoring as prescribing expands.