BV173 engrafted xenograft NSG mouse model treated with imatinib at MTD (50 mg/kg, 1 mg/mouse IP daily) and ESKM at optimal efficacious dose (100 µg IP twice weekly). Mice received 5 weeks of ESKM, imatinib, combination therapy, or no therapy (control). Error bars show the fifth and 95th percentiles. (A) Leukemic growth as measured by luciferase bioluminescent imaging for each of the 4 groups of mice. (B) End of therapy (5 weeks of therapy) image for each of the 4 groups of mice. (C) Three of 5 mice were randomly chosen from each of the 4 groups for BM harvest, and cells were evaluated by flow cytometry. Median staining by flow of the live hCD19⁺ cells (confirmed BV173) were evaluated for BB7 (HLA-A*02:01) and ESK binding.