Validation of Immunogenicity Assessments for Non-Clinical Toxicology Evaluation

Abstract

Abstract To determine the immunogenic potential of biotherapeutics in nonclinical species, assays for anti-drug antibody (ADA) detection must be developed and validated before testing of samples from toxicity studies, to ensure accurate assessment of immunogenicity. ADAs can cause adverse events effecting drug exposure and efficacy complicating the interpretation of the toxicity, pharmacokinetics and pharmacodynamics data. For each compound, a validation is performed prior to study sample analysis. Parameters assessed include Inter analyst, sensitivity, accuracy, drug tolerance, precision, interference and stability of reagents and ADAs. The first step in the validation is to perform precision analysis. Precision is used to determine acceptance criteria for the assay. The inter-analyst experiment is performed by two scientists to show reproducibility. Assay acceptance criteria consists of the acceptable criteria for the pooled negative control (PNC), low quality control (LQC), high quality control (HQC) and LQC/PNC ratio to set the assay cut point. Once this criteria is determined, sensitivity, drug tolerance, interference, and stability are performed to set validation criteria for study samples, reagents, and controls. The drugs to be used on study are labeled with Biotin and Sulfotag and ADAs are assessed utilizing immuno-assay such as a standard ELISA or an electrochemiluminescent immuno-bridging assay. Once study samples are analyzed, it can be determined which subjects have an ADA response elicited by the compound and at what severity. An ADA response helps determine immunogenicity in toxicological evaluations, so it is important to assess for this response when dealing with immunotherapeutic.