Comparing ELISA and surface plasmon resonance for assessing clinical immunogenicity of panitumumab.

Evaluation of the immunogenicity of panitumumab, a fully human anti-epidermal growth factor receptor mAb approved for use in colorectal cancer patients, led to the development of two separate immunoassays for the detection of anti-panitumumab Abs. The first immunoassay used a bridging ELISA capable of detecting 10 ng/ml positive control anti-panitumumab Ab. The ELISA incorporated an acid dissociation step to reduce drug interference and tolerated the presence of approximately 100-fold molar excess of drug.

Detection of neutralizing anti-therapeutic protein antibodies in serum or plasma samples containing high levels of the therapeutic protein.

Neutralizing antibodies against therapeutic proteins can be potentially harmful if the antibody blocks not only the therapeutic activities of the therapeutic protein but also the normal functions of the endogenous counterpart. Detection of the neutralizing anti-therapeutic protein antibodies generally relies on bioassays measuring changes in the biologic activity of the therapeutic protein triggered by the presence of the antibody. Most of the bioassays, particularly the cell-based in vitro assays, fail to detect neutralizing anti-therapeutic protein antibodies when the remaining therapeutic protein level in the assay samples is high.