a. AML cell lines (n=8) were treated with variable concentrations of ONC213 for 72 h. Viable cells were determined using the MTT assay. IC50s were calculated using GraphPad Prism 9.0. Data are graphed as mean ± SEM from three independent experiments. b&c. Primary AML patient samples (n=48) were treated with variable concentrations of ONC213 for 72 h. Viable cells were determined using the MTT assay. IC50s were calculated using GraphPad Prism 9.0. Data are graphed as mean ± SEM in panel c. The data presented are means of duplicates from one experiment due to limited sample availability. d&e. MV4–11, OCI-AML3, and MOLM-13 cell lines were treated with ONC213 for 48 h and then analyzed by Annexin V-FITC/PI staining and western blot, respectively. Mean percent Annexin V+/PI- and Annexin V+/PI+ cells ± SEM are shown. * P<0.05; *** P<0.001 compared to vehicle control (panel d). Representative western blots of whole cell lysates probed with the indicated antibodies are shown (panel e). Abbreviations: cf-PARP, cleaved PARP; cf-Caspase 3, cleaved Caspase-3. f. Primary AML patient samples (n=7) were treated with ONC213 for 48 h. Annexin V-FITC/PI staining was assessed by flow cytometry analysis. Mean percent Annexin V+/PI- and Annexin V+/PI+ cells ± SEM are shown. *** P< 0.001 compared to vehicle control. g. PBMCs from healthy donars were treated with ONC213 for 48 h. Annexin V-FITC/PI staining was assessed by flow cytometry analysis. Mean percent Annexin V+/PI- and Annexin V+/PI+ cells ± SEM are shown. h. MV4–11 cells (1 × 106 cells/mouse) were injected intravenously through the tail vein of immunocompromised NSGS mice. Three days later, the mice were randomized (n=5 mice/group) and treated daily with vehicle control (3% 200-proof ethanol, 1% polyoxyethylene (20) sorbitan monooleate, and USP water), 75 mg/kg ONC213 by p.o., or 125 mg/kg ONC213 by p.o. The mice were treated for 8 consecutive days. The 75 mg/kg ONC213 group was given 2 days off and then treated for another 8 days. The overall survival probability was estimated by the Kaplan-Meier method.