A novel approach to assess domain specificity of anti-drug antibodies to moxetumomab pasudotox, an immunotoxin with two functional domains.

A novel approach to assess domain specificity of anti-drug antibodies to moxetumomab pasudotox, an immunotoxin with two functional domains. J Immunol Methods. 2019 Oct 29;:112688 Authors: Vainshtein I, Sun B, Roskos LK, Liang M Abstract Biologics are potentially immunogenic and can elicit immune response. Complex biologics, such as bispecific antibodies or multi-domain molecules can induce anti-drug antibodies (ADA) with specificity to different domains. Domain specific ADAs may differently affect drug efficacy and safety, and thus, characterization of ADA domain specificity has become a regulatory expectation for multi-domain biologics. Unlike well-established methods for screening, confirmation, titer and neutralizing ADA detection, characterization of ADA domain specificity is an emerging field. The conventional approach for determination of ADA domain specificity is a competitive inhibition with domain-containing molecules. When developing a conventional domain specificity assay for moxetumomab pasudotox, a recombinant anti-CD22 immunotoxin, comprised of two functional domains (CD22-binding fragment and truncated Pseudomonas exotoxin A (PE38), we encountered a bioanalytical challenge. The method was able to detect immunodominant anti-PE38 (ADA-PE) but generated false negative results for low abundant CD22-binding domain ADA (ADA-BD) in a polyclonal sample. Troubleshooting experiments using control samples with varying levels of e...
Source: Journal of Immunological Methods - Category: Allergy & Immunology Authors: Tags: J Immunol Methods Source Type: research