ABSTRACT
Development and Validation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 2.4 Method Transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
The assessment of immunogenicity depends on appropriate detection, quantification, and characterization of ADAs. However, there are multiple challenges for successfully developing ADA assays. Unlike biological assays for measuring drug concentration or protein concentration in human serum, concentrations of ADAs are very low and often in magnitude of ng/mL. Due to the heterogeneity of patient characteristics and multiple epitopes on biotherapeutics,
ADA responses are likely to vary from patient to patient and change during the course of treatment. For instance, immunogenic responses can develop against epitopes previously not immunogenic. In addition, various factors such as the presence of circulating drug and concomitant drug adminstration make accurate detection of ADA even more difficult.
