CD3×CD123 DART suppresses CD123⁺ leukemia xenograft in NSG mice. (A-B) Irradiated NSG mice (n = 5/group) injected with K562^GFP-CD123 cells and treated with DARTs. Bioluminescence imaging on days 3, 12, 19, and 28 showed significant inhibition (P < .0001) of tumor growth in CD3×CD123 DART-treated cells compared with CD3×FITC, FITC×CD123 control DARTs, or no DART (PBS). (C) NSG mice (n = 3-4/group) were sublethally irradiated (300 cGy) on day 0 and injected with primary human AML cells (5 × 10⁶ cells/mouse) from patient number 7 or 8 on day 5. Mice were treated with PBS, CD3×FITC control DART, or CD3×CD123 DART (0.5 mg/kg/day) on days 5 to 8. Peripheral blood, spleen, and bone marrow specimens were obtained 6 weeks after injection and analyzed by flow cytometry for CD45⁺CD33⁺ AML blasts. Data represent the mean and ±SD. *P < .05, **P < .01, ***P < .001.