Re-evaluating the 3-Tier ADA Paradigm: A Case Study Supporting a 1-Tier Signal-to-Noise Ratio Based Strategy for Low-Risk Biotherapeutics

Tim Schauer, Bioanalytical Operations, BioAgilytix, Hamburg, Germany (tim.schauer@bioagilytix.de)

The 3-tiered approach to anti-drug antibody (ADA) testing, comprising screening, confirmatory, and titer assays, has been the established paradigm for clinical immunogenicity assessment for nearly two decades. However, its universal application may not always be scientifically warranted, particularly for therapies with a low immunogenicity risk profile. We hereby explored whether a simplified 1-tier strategy based solely on signal-to-noise ratio (SNR) could be justified and implemented.

This case study presents results from validation of an ADA assay for a transgene-derived product expressed locally with low systemic immunogenicity risk. We evaluated performance under both 3-tier and 1-tier workflows. Data from the confirmatory and titer tiers were compared to a 1-tier approach using a 1% false-positive rate (FPR) screening cut point.

This case study provides a framework for evaluating the suitability of a 1-tier ADA strategy during method development and validation. Direct comparison of 1-tier and 3-tier outcomes within the same dataset offers a practical path to implementing risk-based immunogenicity strategies and clarifies when confirmatory and titer tiers may be unnecessary.

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Short Biography of Presenting Author

Tim Schauer, PhD, is an Associate Principal Investigator at BioAgilytix Europe in Hamburg, where he leads the development, validation, and application of bioanalytical assays for pharmacokinetics, pharmacodynamics, and immunogenicity supporting clinical and preclinical studies.

Tim obtained his Bachelor’s and Master’s degree in Biotechnology from TU Braunschweig. He earned his PhD in Clinical Cancer Research at the Centre for Physical Activity Research in Copenhagen, examining the role of exercise on immune function in patients with cancer. Before joining BioAgilytix in 2023, Tim held a postdoctoral researcher position at the same institution, managing clinical studies and authoring several peer-reviewed publications.