The recoveryELISA--a newly developed immunoassay for measurement of therapeutic antibodies and the target antigen during antibody therapy.

Therapeutic antibodies are an important part of Biopharmaceuticals. They are highly innovative and specific drugs. Additionally, they play a challenging role in new demands in diagnostics because they disturb conventional antibody-based tests, such as immunoassays. The recoveryELISA is a newly developed immunoassay technology for monitoring such therapeutic antibodies or comparable biologics during the therapy. The recoveryELISA determines three results in one test: the free level of antigen (if available in serum), the level of therapeutic antibody and the specific dose-response interaction. The free level of antigen is the amount that can be measured in the immunoassay, as it exists unmasked under assay conditions. The relationship between therapeutic antibody level and neutralization rate of target protein is shown by the so-called 'recovery curve'. The recoveryELISA is demonstrated with the example of Omalizumab/IgE.