Table 2.

In vitro cytotoxicity of SGN-CD123A on primary AML patient samples

SampleCytogeneticsMutations FLT3/ITDMutations NPM-1MDR statusCD123 (MFI)SGN-CD123A IC50, ng/mL
SG037Intermediate+++4800.68
SG016IntermediateNDND+5951.4
SG048Intermediate++1,0701.9
SG025Intermediate++1,190>2.5
SG034Intermediate+++1,2000.22
SG045Intermediate++2,0301.2
SG040Intermediate+ND+2,4000.37
SG039Intermediate+++2,6700.075
SG038Intermediate+2,9500.18
SG018IntermediateNDND+3,1400.12
SG036Intermediate+++3,2600.16
SG026Intermediate++4,6000.22
SG047Intermediate++790>2.5
SG023Intermediate++2,2800.06
SG046Intermediate+ND2,5300.17
SG028Favorable8301.9
SG019Favorable1,480>2.5
SG022Favorable1,4850.56
SG044AdverseNDND+1,1402.5
SG043AdverseNDND+1,3702.5
SG029Adverse+1,8200.46
SG042Adverse+2700.11
SG021Adverse+1,5601.6
  • NOTE: Primary AML samples were incubated with increasing concentrations of SGN-CD123A for 96 hours before flow-cytometry analyses of live/dead cells. Data are expressed as the IC50 value, the concentration of ADC required to give a 50% reduction in cell viability. CD123 expression on bulk tumor cells and the CD34+ subset was determined by flow cytometry and expressed as MFI.

  • Abbreviations: MDR status, fluorescence in the presence of MDR pump inhibitors more than 2-fold above background; ND, not determined.