AEE788 is a vascular endothelial growth factor receptor tyrosine kinase inhibitor with antiproliferative and proapoptotic effects in acute myeloid leukemia.

OBJECTIVE: Aberrant activation of tyrosine kinase receptors is frequently observed in acute myelogenous leukemia (AML). Moreover, activating mutations of the fms-like tyrosine kinase 3 (FLT3) receptor can be found in approximately 30% of patients, thereby representing one of the most frequent single genetic alterations in AML. AEE788, a novel dual receptor tyrosine kinase inhibitor of endothelial growth factor and vascular endothelial growth factor (VEGF), is being studied in several solid tumors with remarkable success. It is not known, however, about the efficacy of this inhibitor in the treatment of AML. Therefore, we investigated the effect of AEE788 in the treatment of three human AML cell lines and seven AML patient samples.

MATERIALS AND METHODS: Cell survival in THP-1, MOLM-13, and MV4-11 cell lines (the two last harboring the FLT3/internal tandem duplication mutation) and AML blasts incubated with 0.5 to 15 microM AEE788 were quantified. We also studied the activation of VEGF/VEGF receptors loop, FLT3, and their downstream effectors (Akt, extracellular signal-regulated kinase, signal transducers and activators of transcription 5, and nuclear factor-kappaB).

RESULTS: Our data showed that AEE788 was a tyrosine kinase inhibitor of FLT3 activity and had antiproliferative and proapoptotic activity in AML-derived cell lines and AML blasts that presented phosphorylation of the FLT3 receptor. Consistently, in these cells AEE788 abrogated VEGF/VEGF receptors activation and the survival signaling pathways studied.

CONCLUSION: Taken together, the activity of AEE788 might represent a promising new option of targeting FLT3 for the treatment of AML.