Recent Advances in Bioanalytical Methods for Quantification and Pharmacokinetic Analyses of Antibody-Drug Conjugates.

Antibody-drug conjugates (ADCs) represent a rapidly expanding class of therapeutics, uniquely combining the specificity of monoclonal antibodies with the potency of cytotoxic small-molecule payloads. Due to their inherent structural complexity and heterogeneous composition, accurate characterization and quantification of ADCs pose significant bioanalytical challenges. This review discusses recent advancements in bioanalytical methodologies, including ligand binding assays (LBAs), liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based approaches, and emerging hybrid LBA-LC-MS/MS platforms. In addition, this review will discuss pharmacokinetic (PK) modeling approaches essential to ADC development, ranging from population PK models to mechanistic frameworks, including physiologically based pharmacokinetic (PBPK) and quantitative systems pharmacology (QSP) models. These modeling strategies allow detailed characterization of ADC absorption, distribution, metabolism, and elimination processes while also accounting for complexities introduced by payload deconjugation and drug-to-antibody ratio variability. By integrating robust bioanalytical methods with advanced modeling techniques, this review provides researchers with essential insights to enhance ADC characterization, inform experimental design, and ultimately facilitate the development of safer, more effective therapeutic candidates.