Background: Antibody–drug conjugates (ADCs) are a promising modality for cancer treatment; however, considering their complicated nature, analytical complexity in understanding their pharmacokinetics and pharmacodynamics in the body presents a significant challenge. Results: Vorsetuzumab maleimidocaproyl valine-citrulline p-aminobenzyloxycarbonyl monomethyl auristatin E was used to develop pretreatment and analytical workflows suitable for ADCs. Monomethyl auristatin E release and drug-to-antibody ratio retention were consistent in mouse plasma but inconsistent in monkey and human plasma. Further, metabolites were species-specific. Microflow-liquid chromatography/high-resolution mass spectrometry (LC–HRMS) resulted in a 4–7-fold improvement in detection sensitivity compared with conventional flow LC–HRMS. Conclusion: Microflow-LC–HRMS can be a useful tool in understanding the complex properties of ADCs in the body from a drug metabolism and pharmacokinetics point of view.
Plain language summary
Drug-to-antibody ratio (DAR), payload release and metabolite profile of deconjugated payload-linker of vorsetuzumab maleimidocaproyl valine-citrulline p-aminobenzyloxycarbonyl monomethyl auristatin E, an antibody–drug conjugate (ADC) with cleavable linker and monomethyl auristatin E as payload, are reported. Species-specific retention of DAR, payload release and metabolite patterns of deconjugated payload-linker of the ADC are summarized. Exploring the fate of payload-linker moieties deconjugated from ADCs in the body is also vital to understanding pharmacological activity and toxicity. Species-specific metabolite patterns of the ADC provided insight into the importance of optimization of the payload-linker moiety in biological samples, especially in humans. In terms of a more sensitive analytical platform for drug metabolism and pharmacokinetic evaluation, microflow-liquid chromatography/high-resolution mass spectrometry (LC–HRMS) in DAR analysis was found to take advantage of the improvement of detection sensitivity compared with conventional LC–HRMS. Because ADCs are a complex drug modality, these results indicated the importance of evaluation of ADCs from a drug metabolism and pharmacokinetics point of view to understand the pharmacology and toxicology of ADCs, more precisely.
Drug-to-antibody ratio (DAR) of antibody–drug conjugates (ADCs) is important in estimating pharmacological and toxicological effects in the body. Microflow-liquid chromatography/high-resolution mass spectrometry was established to monitor DAR retention in different ADC-containing biological samples.
Keywords:
- antibody–drug conjugate
- deconjugation
- drug-to-antibody ratio
- high-resolution mass spectrometry
- metabolism of payload
- microflow liquid chromatography
- monomethyl auristatin E
- species-specific
- vorsetuzumab