Characterization of Critical Reagents for Ligand Binding Assays

the immunogenicity of biotherapeutic molecules, and determine drug concentrations for pharmacokinetic analyses. The accuracy and performance of LBAs, however, depends on the quality of key reagents, called critical reagents. The Global Bioanalysis Consortium (GBC) and the European Medicines Agency classify critical reagents as analyte specific or binding reagents, specifically antibodies; peptides; engineered proteins; antibody, protein and peptide conjugates; reagent drugs; aptamers and anti-drug antibody (ADA) reagents including positive and negative controls (King et al. 2014). In 2014, the GBC expanded this definition to include biological matrices, in some instances (King et al. 2014). Utilizing poorly characterized critical reagents in LBAs could lead to inaccurate conclusions and delays in the drug development process. It is therefore necessary to properly characterize them early in the drug development program. However, their characterization and management varies between bioanalytical laboratories.