Motixafortide (BL-8040)

Treatment with BL-8040 induces the robust mobilization of AML blasts from the BM. In addition, AML cells exposed to BL-8040 undergoes differentiation. BL-8040 induces the apoptosis of AML cells in vitro. This apoptosis is mediated by the up-regulation of miR-15a/miR-16-1, resulting in down-regulation of the target genes BCL-2, MCL-1 and cyclin-D1. Overexpression of miR-15a/miR-16-1 directly induces leukemic cell death. BL-8040-induced apoptosis is also mediated by the inhibition of survival signals via the AKT/ERK pathways.^[1]

Cells are seeded in triplicate at 2×10⁵ cells/well in a total volume of 250 μl in a 96-well plate in medium supplemented with 1% FCS RPMI medium for 24hr in the presence of BL-8040/AMD3100 (0.1, 1, 10 or 20μM) or ABT-199 (0.01, 0.1, 1 or 10μM). To test the combination of BL-8040 and ABT-199, cells are incubated for 24hr with BL-8040 (20μM) and ABT-199 (0.01, 0.1, 1 or 10μM). To test the combined effects of BL-8040 and AC220, cells are incubated for 48 hr with BL-8040 (20μM), AC220 (50nM) or a combination of the two. After incubation, cells are stained with propidium iodide (PI), and the percentage of dead cells (PI+ cells) in the culture is measured using a FACSCalibur machine.

BL-8040 induces the apoptosis of AML cells in vivo. Treatment with a BCL-2 inhibitor induces apoptosis and acts together with BL-8040 to enhance cell death. BL-8040 also synergizes with FLT3 inhibitors to induce AML cell death. Importantly, this combined treatment prolongs the survival of tumor-bearing mice and reduces minimal residual disease in vivo.^[1]