• Novel High Sensitivity Bispecific Antibody ELISA

    Posted on Aug 6, 2023

    Introducing Our Cutting-Edge ELISA Method

    Bispecific antibodies are a groundbreaking class of molecules that hold tremendous promise for revolutionizing targeted therapies. These unique antibodies are designed to simultaneously bind two different targets at each terminus.  Some bispecific constructs consist only of Fab pieces, or Fv pieces, the ~25,000 Da complete antigen binding site of one Light chain. These smaller “nanobodies” are a challenge for an ELISA technique. An example is blinatumomab or BlincytoTM that links CD3 bearing human host killer T cells with CD19 bearing B cell malignances leading to their death, see the figure below.

    Key challenges in developing an ELISA for bispecific antibody constructs are listed below, including related to being more sensitive to degradation and lower affinity due to having a scFv region rather than a Fab2 dimer property or a complete two-antigen binding arms of an IgG molecule.

    Bispecific antibody properties Challenge
    Confirmation of Bispecific Antibodies Validating the bispecific nature and functionality of both antigen-binding domains
    Conformational Changes Overcoming induced conformational changes  upon binding targets
    Differential Binding Affinities Quantifying across concentrations when  each target has varying affinities
    Detection Assay Design Developing specific assays without cross-reactivity with other antibody formats
    Analytical Sensitivity Detecting low levels of bispecific antibodies for accurate PK/PD analysis
    Sample Matrix Interference Overcoming the interference from complex biological matrices that impact assay sensitivity and reliability.


    Key features and benefits of our ELISA method

    The principle of the MarinBio bispecific ELISA is shown in the figure below.


    The sensitivity of MarinBio’s ELISA surpasses that other bispecific antibodies.

    The reported sensitivity of the ELISA for various bispecific antibodies is shown in the Table below.

    Bispecific Antibody ELISA Sensitivity
    CD3 x BCMA (B cell maturation antigen) 4ng/mL (1)
    CTLA-4 (cluster of differentiation 152, CD152) x OX40 (tumor necrosis factor receptor superfamily, member 4,TNFRSF4), ATOR-1015 4ng/mL(2)
    Blinatumomab, BlincytoTM, anti cD3 x anti cD19 50 -100ng/mL (3)

    The sensitivity of the MarinBio’s bispecific antibody ELISA MarinBio is 0.016ng/mL in buffer and 0.06ng/mL in neat serum.

    Results of the MarinBio bispecific Fab ELISA.

    Key features of the MarinBio’s bispecific Fab ELISA

    Specificity: The ELISA assay is designed to specifically detect both target proteins of the bispecific construct, ensuring accurate and reliable results without interference from other antibody formats.

    Sensitivity: The method has a lower limit of quantitation of 0.060ng/mL while using only 17µL serum per well.

    Versatility: MarinBio’s ELISA method can be applied to various bispecific antibody formats.,

    Flexibility: The assay can be customized to accommodate specific study objectives, whether it is pharmacokinetics/pharmacodynamics (PK/PD) analysis, preclinical toxicology studies, or clinical trials.

    GMP/GLP ELISA: MarinBio has validated this bispecific antibody ELISA and can adapt the technology to detect other bispecific antibodies in GLP or cGMP assays.

    Conclusion: The development of a novel bispecific antibody ELISA method marks a significant leap forward in the analysis and characterization of bispecific nanobodies.

    Marin Biologic Laboratories is proud to offer this innovative service, supporting researchers, pharmaceutical / biotech companies, in their quest to develop and optimize bispecific antibody-based treatments.







    “Parts of the figure were drawn by using pictures from Servier Medical Art. Servier Medical Art by Servier is licensed under a Creative Commons Attribution 3.0 Unported License (https://creativecommons.org/licenses/by/3.0/).”