Functional assays to assess binding properties and potency are essential Critical Quality Attributes to meet ICH Q6B and cGMP requirements. Functional assays are tailored, depending on the mechanism of action, to meet specific requirements, which may vary depending on therapeutic protein type.
As example, for mAbs, cell-based neutralization assays aim to assess Fab-associated functions and ADCC and CDC assays to measure Fc-associated functions of mAbs. On the other hand, assessing the potency of various types of insulin and insulin analogues requires to determine both isoforms of the insulin receptor (IR-A and IR-B) activation in a cell-based assay, and at least metabolic assays (e.g., Glucose uptake, Lipogenesis, Inhibition of lipolysis). Affinity is often assessed with Enzyme-Linked Immuno Sorbent Assays (ELISA) or Surface Plasmon Resonance (SPR) to measure on-off kinetics.
Our expertise in development and validation of bespoken functional assays can successfully support comparative testing of biologics and cGMP batch release testing.