Combination studies between nilotinib and HG-7-85-01 against BCR-ABL–positive leukemia. (A) In vitro combination study: 2-day treatment of 32D.p210-luc⁺ cells with imatinib, HG-7-85-01, or a combination. Calcusyn results: 25% effective dose (ED₂₅) = 0.96795 (nearly additive); ED₅₀ = 0.85587 (slight synergism); ED₇₅ = 0.78257 (moderate synergism); and ED₉₀ = 0.73747 (moderate synergism). (B) Two-day treatment of 32D.p210-luc⁺ cells with nilotinib, HG-7-85-01, or a combination. (C-D) In vivo analysis of the combination of nilotinib and HG-7-85-01. (C) Plotted are bioluminescence values shown as percentage of baseline control values. In vivo combination study between HG-7-85-01 and nilotinib against nonmutant BCR-ABL: Day 8 after intravenous injection of 800 000 32D.p210-luc⁺ cells/mouse. Vehicles (n = 4): 2 vehicles were treated 2 times daily, 2 vehicles were treated 1 time daily. Nilotinib treatment group: Treatment mice were administered 1 time daily 20 mg/kg nilotinib (n = 4), 1 time daily 100 mg/kg HG85 (n = 2), or 1 time daily a combination of nilotinib and HG85 at the aforementioned doses (n = 2). Baseline imaging was performed 1 day after intravenous injection of 32D.p210-luc⁺ cells. Mice were treated for a total of 7 days before imaging. (D) Values plotted are percentage spleen/total weights. Mice were killed and spleens dissected 21 days after the last imaging day (day 8 after intravenous injection of cells).