Pozelimab is a monoclonal antibody designed to inhibit the complement component C5, a key protein in the complement system involved in inflammatory and immune responses. By blocking C5, pozelimab prevents the formation of the membrane attack complex (MAC), which reduces uncontrolled complement-mediated damage to host cells. This antibody has shown therapeutic potential in rare complement-driven diseases, particularly in conditions like CD55-deficient protein-losing enteropathy (PLE), also known as CHAPLE disease. In such disorders, unregulated complement activation leads to gastrointestinal inflammation, severe protein loss, and malnutrition. Pozelimab helps restore immune balance by suppressing excessive C5 activity, leading to improved intestinal function and clinical stability. It is also being explored in other complement-mediated conditions where targeted inhibition of C5 can prevent tissue damage, offering a precision medicine approach for patients with limited treatment options. Due to its high specificity, pozelimab minimizes broad immunosuppression, reducing the risk of infections compared to non-selective therapies.