Functional characterization of CLL1-ADC. (A) A schematic of CLT030 (CLL1-ADC) including anti-CLL1 antibody, linker, and payload structures. Cytotoxicity activity of CLL1-ADC on (B) OCI-AML2, (C) HL60, and (D) OCI-AML5 cells or OCI-AML5 cells devoid of CLL1 expression (KO cells). CLL1-ADC in solid blue line, IgG-ADC in dotted green line on OCI-AML5 cells, CLL1-ADC on CLL1 KO cells in gray solid line, and IgG-ADC on CLL1 KO cells in dotted light green line. (E) Correlation plot of log of IC₅₀ determine from CLL1-ADC cytotoxicity on AML cells as listed in Table 2 vs log of MFI of CLL1 antibody binding to the same listed cells.