Lirentelimab (also known as AK002) is an investigational, humanized monoclonal antibody that targets sialic acid-binding immunoglobulin-like lectin 8 (Siglec-8), an inhibitory receptor selectively expressed on eosinophils, mast cells, and to a lesser extent on basophils. By engaging Siglec-8, lirentelimab induces antibody-dependent cellular cytotoxicity (ADCC) and apoptosis in eosinophils and inhibits mast cell activation. This dual mechanism aims to deplete pathogenic eosinophils and dampen mast cell-mediated inflammation. It is being developed for the treatment of eosinophil and mast cell-driven diseases, with clinical trials in eosinophilic gastritis/gastroenteritis (EG/EoG), eosinophilic esophagitis (EoE), and chronic spontaneous urticaria (CSU).