Lecanemab treatment for mild alzheimer's disease with high risk of cerebral hemorrhage: a case report.

BACKGROUND

Lecanemab has been approved for the treatment of mild cognitive impairment due to Alzheimer's disease (AD) and mild AD dementia based on the efficacy in slowing cognitive decline and preliminary safety data from the phase Ⅲ Clarity AD trial. However, this trial excluded patients with high risk of cerebral hemorrhage, such as individuals with intracranial aneurysms or > 4 microhemorrhages.

CASE PRESENTATION: A 70-year-old male with mild AD, intracranial aneurysm, microhemorrhages, and APOE ε3/ε4 genotype received lecanemab after multidisciplinary evaluation and informed consent. Over six months of intensive monitoring, cognitive function stabilized with no deterioration, daily activities were preserved, microhemorrhages remained stable (with one new small lesion noted at 3 months), and no aneurysm rupture or severe adverse events (including amyloid-related imaging abnormalities) occurred.

CONCLUSIONS

This case suggests that, despite hemorrhage risks, lecanemab may have a manageable risk-benefit profile in selected real-world AD patients under intensive monitoring and multidisciplinary care, with its application beyond clinical trial criteria requiring more nuanced and individualized consideration.