Abstract 667: IMGN853, a folate receptor (FR) α-targeting antibody-drug conjugate (ADC), is highly effective against xenograft models with clinically relevant levels of receptor expression

IMGN853 comprises the anti-FR-α antibody M9346A conjugated to the cytotoxic maytansinoid molecule DM4 via a stable disulfide-containing linker, sulfo-SPDB. IMGN853 is currently in phase I clinical testing; promising clinical results were reported at ASCO 2013. To analyze determinants of the sensitivity of FR-α positive cells to IMGN853, we examined antigen density on the cell surface, internalization and processing of IMGN853, and sensitivity of...