An electrochemiluminescence (ECL)-based assay for the specific detection of anti-drug antibodies of the IgE isotype

Abstract To address a possible linkage between the occurrence of the hypersensitivity reactions and the induction of IgE anti-drug-antibodies (ADA), a drug specific IgE ADA assay was developed using electrochemiluminescence (ECL) technology. In the assay a drug-specific IgE isotype chimeric antibody was generated and used as an ADA positive control. The biotinylated drug X (an antibody) and ruthenium-labeled omalizumab (an anti-human IgE antibody) were used as capture and detection reagents, respectively. The binding affinities of the chimeric IgE isotype positive control have been shown to be highly comparable to drug X and drug Y (drug X is the 2nd generation of drug Y), indicating that it could serve as a highly useful control to compare and contrast the relative ability of the two generations of drug to elicit IgE ADA responses. The assay cut point factor (CPF) was estimated to be 1.13. The cut point factor derived from normal human serum samples was statistically equivalent to the cut point factor determined from targeted population samples. The assay could detect less than 250 ng/mL of IgE antibodies in the presence of 300 μg/mL drug X. The assay sensitivity was