Rituxan ADCP Assay
Sartorius Stedim BioOutsource has a significant level of expertise and capability in the analysis of effector functions for a range of monoclonal antibody (mAb) based therapeutic products. This includes off-the-shelf methods for the analysis of Antibody Dependent Cellular Phagocytosis (ADCP), Antibody Dependent Cell-mediated Cytotoxicity (ADCC) and Complement Dependent Cytotoxicity (CDC). In addition, we can also support the analysis of binding kinetics to the full range of Fc-gamma receptor proteins and relevant complement system components, in order to provide a comprehensive depiction of the effector function of an antibody.
Rituximab is a therapeutic mAb which targets CD20 that is present on the surface of B cells. Such B cells are sometimes present in higher abundance in patients suffering from lymphomas and leukaemias. By targeting CD20, Rituximab signals for B cell depletion by calling upon the full range of Fc-Fc gamma receptor interaction activities.
ADCP is a complex activity which utilises the patient’s immune system through the recruitment of macrophages, monocytes, neutrophils and dendritic cells which attach and kill antigen-expressing target cells recognised by the complementarity determining region of the antibody. Once the target cell has been recognised by the Fab domain of the mAb, Fc-gamma Receptor I (FcγRI, CD64) Fc-gamma Receptor IIa (FcγRIIa, CD32a), Fc-gamma Receptor IIIa (FcγRIIIa, CD16a) expressed on the effector cell binds the projected Fc region resulting in the activation of intracellular signalling pathways leading to the phagocytic destruction of the target cell.
Utilising a gene reporter bioassay approach, we have developed a method to analyse the ADCP activity of a mAb, without the obstacles and run-to-run variability evident in a classical assay. This assay has shown the appropriate attributes allowing in-house qualification following the principles of ICH harmonised guidelines for validation of analytical procedures (ICHQ2).
Contact our scientists today to discuss your ADCP assay requirements.