Free versus total ligand-binding assays: points to consider in biotherapeutic drug development

“It is therefore very helpful for end users of bioanalytical data such as pharmacokinetic scientists and toxicologists to work together with bioanalytical scientists to assess the needs, technical feasibility and challenges of developing suitable bioanalytical assays in order to form a sound bioanalytical strategy.” Accurate quantitative information on biotherapeutic drug concentrations from both preclinical and clinical studies is critical to support drug development. These data reveal the relationship between drug concentrations in circulation and drug exposure; help characterize pharmacokinetics (PKs) of the drug candidates; facilitate projection of doses for human Phase I–III studies; and provide the foundation of PK/pharmacodynamic (PD)...