Ersodetug is an investigational, fully human monoclonal antibody developed as a novel therapy for congenital and acquired forms of Hyperinsulinism (HI), a condition characterized by excessive and dysregulated insulin secretion leading to severe hypoglycemia. It functions through a unique, allosteric mechanism of action. Unlike traditional insulin receptor antagonists that directly compete with insulin for binding, ersodetug binds to a distinct, allosteric site on the insulin receptor (IR). This binding negatively modulates the receptor's signaling in response to insulin or related hormones (such as IGF-1 and IGF-2). By acting as a negative allosteric modulator, it effectively dampens the downstream signaling cascade (e.g., through the PI3K/Akt pathway) that would otherwise be overactivated in HI, thereby reducing the inappropriate cellular responses (like excessive glucose uptake and inhibition of gluconeogenesis) that cause dangerous low blood sugar.