Affinity capture elution bridging assay: A novel immunoassay format for detection of anti-therapeutic protein antibodies

Increased emphasis on the development of biologics has placed a significant focus on anti-drug antibody (ADA) detection. To address this need, several immunoassay formats have been described for use in characterizing potential immune responses. Two commonly utilized methods include the affinity capture elution (ACE) and bridging formats. While these approaches have been effective in supporting many clinical initiatives, both possess potential disadvantages. Here, we compare these standard methods to a novel format that addresses these noted drawbacks. A novel assay format has been designed to incorporate the benefits of the ACE and bridging methods while overcoming the disadvantages incurred with each approach. The described ACE–Bridge format exhibits excellent sensitivity and precision while providing superior drug tolerance when compared to bridging formats. Further, this assay format is not susceptible to the endogenous target interference that can be an issue in the ACE format. The ACE–Bridge format provides an often superior option as a screening method to monitor patient ADA responses. This method is unique in its ability to measure ADA in the presence of high circulating endogenous target concentrations (>100ng/mL) while demonstrating very high drug tolerance.