Trabikibart is a fully human βc-specific monoclonal antibody, designated CSL311, that binds with picomolar affinity to the cytokine-binding epitope of the human βc receptor. Trabikibart exhibits potent inhibitory activity against the collective biological effects of IL-3, GM-CSF, and IL-5 on eosinophil survival, positioning it as a promising biologic agent for the study of chronic inflammatory and eosinophil-associated disorders.