Prolonged survival of TCL1 leukemia-engrafted mice by OSU-T315. (A) C57BL/6 mice engrafted with TCL1 leukemia cells were treated orally with vehicle or 50 mg/kg OSU-T315 daily after appearance of 10% leukemia cells in the peripheral blood. WBCs were monitored by blood smear slides weekly until euthanization was required. Data represent WBC counts after 4-week treatment. (B) Overall survival was analyzed after treatment starts (n = 6 per group). (C) C57BL/6 mice engrafted with TCL1 leukemia cells were treated by intraperitoneal injection with vehicle or 25 mg/kg OSU-T315 once daily for 2 weeks after the appearance of 5% CD19⁺, CD5⁺ leukemia cells among CD45⁺ peripheral blood mononuclear cells. OSU-T315 was formulated in phosphate-buffered saline containing 10% Cremophor EL (Sigma). After a 2-week daily scheme, leukemic mice were treated every other day with vehicle or 25 mg/kg OSU-T315 to prevent weight loss. The percent of leukemic cells was monitored weekly by flow cytometry until euthanization was required. Overall survival was analyzed (n = 9 for each group). (D) Data represent the pharmacokinetics of OSU-T315 in plasma after intravenous, intraperitoneal, or oral dosing (n = 6 per group).