Fc function of a new intravenous immunoglobulin product: IGIV 10% triple virally inactivated solution

Background and Objectives Baxter AG has developed a new liquid intravenous immunoglobulin product [Immune Globulin Intravenous (IGIV) 10%] using a new manufacturing procedure. A modified Cohn fractionation and ion exchange chromatography is used to produce an IgG solution with no alterations to the Fc region. Three dedicated virus reduction steps are included: solvent‐detergent treatment, nanofiltration, and incubation at low pH and elevated temperature in final formulation. We applied the reference method of the European Pharmacopoeia (EP) together with a flow‐cytometric binding assay for the evaluation of the Fc function of the new product. Materials and Methods The EP reference method was done as described in the EP. The flow‐cytometric method measured binding of IgG to Fc receptors of human monocytic THP‐1 cells after exclusion of apoptotic cells. Results Sixteen lots of the new product expressed Fc functions between 84% and 110% when analysed with the EP reference method and Fc‐binding activities between 82% and 121% when determined by the flow‐cytometric method. Conclusion All tested lots of the new product demonstrated a high level of Fc activity and met the requirements of the EP for Fc function.