LC/MS versus Immune‐Based Bioanalytical Methods in Quantitation of Therapeutic Biologics in Biological Matrices

Abstract This chapter reviews the main characteristics of liquid chromatography/mass spectrometry (LC/MS) and ligand‐binding assay (LBA) methods. If an LBA method for biotherapeutics quantification is well established, it usually provides sufficient sensitivity and selectivity and is considered the method of choice. The LC/MS method emerged as an alternative strategy for quantification of proteins of interest in complex biological matrices. Multiplexed capacity and selectivity are critical features determining the applicability of a bioanalytical method. Well‐established LBA methods usually provide adequate sensitivity for quantification analysis of biotherapeutics in preclinical/clinical pharmacokinetic (PK)/pharmacodynamic (PD) study. LC/MS with high resolution analyzer has become a promising technology for characterization of antibody‐drug conjugate (ADC) in the recent years. An affinity capture capillary LC coupled to quadrupole‐time‐of‐flight (TOF) MS has been employed to analyze anti‐MUC16 TDC, which obtained bothin vitroandin vivodrug‐to‐antibody ratios (DARs) information.