Precision Immunomodulation in Pregnancy — Lessons from Nipocalimab

The development of neonatal Fc receptor (FcRn)-blocking therapies represents a profound shift in the management of maternal alloimmune disease, offering a mechanism-based strategy to prevent the transplacental transfer of pathogenic immunoglobulin G (IgG). 1 Nipocalimab, a fully human IgG1 monoclonal antibody that inhibits FcRn-mediated IgG transport, 2 is the first of such therapies to be evaluated in pregnancy.In the phase 2 UNITY study, 3 antenatal nipocalimab was associated with decreased fetal anemia, and fewer intrauterine transfusions, as compared with a historical benchmark, among women at high risk of early-onset severe hemolytic disease of the fetus and newborn, a condition traditionally associated with substantial fetal morbidity and procedural risk.