Biotransformation Case 1. These data were from cynomolgus monkey plasma samples collected at different time points after dosing with DAR8 cysteine conjugated ADC (ADC1). This ADC appeared to be relatively stable and only a few biotransformation products were observed, including maleimide ring hydrolysis on the linker, and cysteine adduct on free thiol exposed after payload deconjugation. Other major species observed in the intact data were plasma albumin and cysteine adduct of albumin.