Validation of Anti-Adeno Associated Virus Serotype rh10 (AAVrh.10) Total and Neutralizing Antibody Immunogenicity Assays

Purpose

Immunogenicity assessments as inclusion/exclusion criteria to predict investigative drug safety and efficacy are critical in the development of Adeno-Associated Virus (AAV)-based gene therapies. Although multiple assay formats which measure distinct endpoints (i.e., binding versus neutralizing antibody activity) are applicable and being used in this context, it is not clear which assays should be selected and at what stage of drug development these methods should be implemented. Here, we provide data for the validation of a total antibody (TAb) assay and a neutralizing antibody (NAb) assay for detection of anti-AAVrh.10 antibodies with the intent to use these assays for screening patients prior to enrollment in an AAVrh.10 gene therapy clinical study. The AAVrh.10 TAb and NAb validation data sets are compared in terms of minimum sample dilution, cut point, assay sensitivity, drug tolerance, and precision. Further, a concordance analysis was performed to determine if the assays produced similar results when used for screening a population of potential patients. This comparison is meant to provide insight into the utility of each assay as a potential tool for inclusion of select individuals into clinical studies.