Progress in the assessment of immunogenicity over the past decade has been rapid; therapeutics in late-phase clinical studies today are subject to antidrug antibody analyses that have evolved considerably since the start of their clinical development. Data from bridging and direct ELISA methods used for the analysis of antidrug antibodies generated in response to an antibody therapeutic will be presented. The case study will highlight some of the challenges faced and the learning points gained from supporting immunogenicity analysis for these therapeutics.