In vivo biotransformations of antibody-drug conjugates.

The selective delivery of potent pharmacologically active compounds to target tissue or cells by antibody-drug conjugates makes this immuno-conjugate a promising modality for the treatment of cancers. A thorough understanding of the structural integrity of the linker, the payload and the conjugation site during biological exposure is critical throughout the process of novel linker-payload design and optimization of PK profile. This understanding is a key aspect of the effort to maximize efficacy while minimizing toxicity in preclinical testing and to ensure the translation to the clinical setting. The complexity of this bioconjugate modality is a source of significant challenge for analytical interrogation and analysis in vivo. Therefore, we report herein a survey of various types of biotransformation events that have been elucidated in recent years.