(A) Dose- and time-dependent effects on cellular proliferation measured
by trypan blue exclusion in primary AML cells treated with increasing concentrations of
ALRN-6924 (data shown as mean ± SD of technical triplicates). (B)
Dose-dependent effects of ALRN- 6924 on clonogenic capacity of primary AML cells (n = 4)
compared to healthy peripheral blood mononuclear cells (PBMNCs) isolated from cord blood (n =
3) and bone marrow mononuclear cells (BMMNCs) isolated from one AML patient in clinical
remission (data shown as mean ± SD; P statistics determined using
unpaired two-tailed Student’s t test). (C) FACS analysis
of cellular viability (left panel) and apoptosis (right panel, plotted as fold change relative
to baseline) measured by annexin V and DAPI staining in leukemia stem cell-enriched
(CD34+CD38-) primary bone marrow cells from AML patients (n = 3) and
healthy donors (n = 3) 48 hours after treatment with 5 μM ALRN-6924 (data shown as mean
± SD, unpaired one-tailed Student’s t test). (D)
Serial replating capacity of AML cell lines treated with either 0.5 μM ALRN-6924 or 0.5
μM RG7388, measured by CFC assay. (E) Human AML cellular engraftment
analysis by FACS of mouse bone marrow (BM) from experimental animals 5 weeks after the start of
treatment. Human AML cells were identified by costaining mouse BM cells with human CD45 and
mouse CD45.1 antibodies [BIW, two times per week (n = 10); TIW, three times per week (n = 5)].
(F) Kaplan-Meier curve showing overall survival of mice xenotransplanted with
MOLM13 AML cells and treated with ALRN-6924 or vehicle. (G) Median survival times
for the curves shown in (F). (H) FACS analysis of mouse hematopoietic stem and
progenitor frequencies after treatment with ALRN-6924 (20 mg/kg) TIW for 4 weeks (HSC = LSK
CD150+CD48-, LSK = Lin-Sca+Kit+, and LK
= Lin-Kit+ progenitors). (I) Neutrophil and platelet counts
assessed by Hemavet analysis of peripheral blood from mice (n = 10) on treatment with ALRN-6924
(20 mg/kg) TIW for 4 weeks. Data shown as the mean ± SD; *P < 0.05, **P <
0.01, ***P < 0.001