Alzheimer's disease (AD) presents a pressing global health challenge, with amyloid-β (Aβ) accumulation in the brain being a hallmark feature. While monoclonal antibodies targeting Aβ have shown cognitive benefits, safety concerns remain. Here, we introduce the Amytrapper catheter, a novel extracorporeal device developed by Recombinant Technologies to trap circulating Aβ using a retro-inverso peptide conjugated to polyethylene glycol. Through in vivo experiments using a rat model of AD, we demonstrate significant reductions in blood Aβ levels and behavioral improvements following Amytrapper catheter treatment. This innovative approach holds promise as a disease-modifying therapy for AD, offering a complementary strategy to existing treatments and advocating for further clinical development.