Introduction <p>Nipocalimab is a high-affinity, fully human, immunoglobulin G (IgG) 1 monoclonal antibody that inhibits the neonatal Fc receptor. Nipocalimab is under development for the treatment of various IgG autoantibody- and alloantibody-mediated diseases. This study assessed the safety, pharmacokinetics (PK), and pharmacodynamics (PD) of a single dose of nipocalimab in healthy Chinese volunteers.</p> Methods <p>In this phase I, open-label study, healthy volunteers received single doses of intravenous (IV) nipocalimab at 15, 30, or 45&#xa0;mg/kg. The primary objective was to assess the PK following a single administration of nipocalimab. Secondary objectives included the PD effects of nipocalimab on change from baseline in total serum IgG levels, safety, and tolerability.</p> Results <p>A total of 30 healthy Chinese volunteers (mean age 31.0&#xa0;years, 93.3% men) received single doses of IV nipocalimab. Following a single infusion of nipocalimab, mean exposure increased as the dose of nipocalimab increased. Maximum serum nipocalimab concentrations increased proportionally with doses, whereas the area under the concentration–time curve increased by greater than a dose-proportional manner. Nipocalimab led to dose-dependent reductions in serum IgG levels from baseline; this decrease was sustained over a longer period of time with higher dose levels. Nipocalimab was generally well tolerated, with an acceptable safety profile, across all three doses; most of the treatment-emergent adverse events (TEAEs) were mild. Higher doses of nipocalimab were not associated with increased frequency of TEAEs.</p> Conclusion <p>Our findings add to the evidence on the safety, tolerability, and PD of nipocalimab in the Chinese population, and support for the treatment of pathogenic IgG-mediated diseases in this population.</p> Trial registration <p>ClinicalTrials.gov NCT05151692.</p>