Aim: To demonstrate the importance of critical reagent characterization for immunogenicity assay development for multi-specific drugs using two case studies.Methods: Bridging anti-drug antibody (ADA) assay with acid-dissociated samples were used for both cases.Results: In the first case study, the unexpected interference in an ADA assay from clinical samples was identified; a model was created to replicate the issue, and an anti-target antibody was identified to mitigate the target interference. In the second case study, an issue due to non-specific binding of a domain-specific confirmatory reagent was identified, and various mitigation techniques were evaluated.Conclusion: A thorough characterization of the critical reagents helped identify the issues with these ADA case studies and provided strategies for resolving them.
Keywords: LBA; anti-drug antibody; critical reagents; immunoassay; immunogenicity; multi-specific antibodies.
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