Compatibility study of routine chromatographic analytical testing of antibody-drug conjugate payload-linkers

Payload-linkers are essential components of antibody-drug conjugates (ADCs), connecting the antibody to the cytotoxic drug through complex chemical structures that include PEG chains, peptide sequences (e.g., GGFG, VC, etc.) linked by disulfide, carbonate, amide, or pyrophosphate bonds. These features make payload-linkers highly sensitive to hydrolysis, oxidation, photodegradation, moisture absorption, and metal ion complexation, posing significant challenges during analytical testing. Their instability requires strict control of sample preparation, storage, and analysis conditions to ensure accurate and reliable data. This study aimed to identify suitable analytical conditions for different structural types to support robust characterization and quality control. We systematically evaluated preparation processes, diluents, mobile phases, consumables, and instrumentation to minimize degradation and variability. The optimized method incorporates inert consumables, chromatography columns with appropriate packing material and pore size, and stability-preserving diluents to reduce analytical instability. These measures enable reproducible and accurate analysis of payload-linkers, supporting specification setting and quality assurance in ADC development. Our findings underscore the importance of tailored analytical strategies for structurally complex and highly reactive intermediates in bioconjugation platforms.