Mal-PEG3-C2-acid can be used to synthesis linker-payload 16 (compound 15) and 20 (compound 18). linker-payload 16 amd 20 is conjugated to DAR1.9 and DAR1.7[1]. ADC 23 and 24 are Neolymphostin ADCs that composes of DAG 1.9 and DAG1.7 linked to PIKK inhibitors with linker-payload 16 and 20, respectively[1]. ADC24 demonstrates cytotoxic activity against BT474 and N87 cell lines with IC50 of 195 and 202 nM, respectively[1]. ADC23 demonstrates cytotoxic activity against BT474 and N87 cell lines with IC50 of 286 and 274 nM, respectively[1].