Refined analysis of antigen-specific antibody responses--a new one-step tool in immunogenicity studies

Immunogenicity is a continuous efficacy and safety issue of biopharmaceuticals. Pre-clinical models for prediction of immunogenicity itself as well as biomarkers to reveal potential mechanisms behind an already existing antibody response are still needed. A sensitive, robust and specific immunogenicity assay has therefore been developed that can detect and measure antibodies of five classes against an administered recombinant human protein drug. Additionally, a validation was performed to evaluate the reproducibility and specificity of this newly developed assay. The production of drug-induced antibodies in mice injected with a recombinant human protein drug has been measured by using a modified version of a multi-parametric bead analysis technique. Competitive binding was used to verify drug-specificity of the antibodies. Results showed that the mouse response against the recombinant human protein was IgG1- and IgG2b-specific, suggesting that the drug-induced response was driven by both Th1/Th2 cells; a finding confirmed by measurement of the cytokine profile. With this assay, anti-drug antibody class and subclass screening may be executed in one step.