Intracellular Catabolism of an Antibody Drug Conjugate with a Noncleavable Linker.

Antibody drug conjugates are emerging as a powerful class of antitumor agents with efficacy across a range of cancers; therefore, understanding the disposition of this class of therapeutic is crucial. Reported here is a method of enriching a specific organelle (lysosome) to understand the catabolism of an anti-CD70 Ab-MCC-DM1, an antibody drug conjugate with a noncleavable linker. With such techniques a higher degree of concentration-activity relationship can be established for in vitro cell lines; this can aid in understanding the resultant catabolite concentrations necessary to exert activity.