Description
InformationMI-503 MI-503 is a potent and selective Menin-MLL inhibitor with IC50 of 14.7 nM. It shows pronounced growth suppressive activity in a panel of human MLL leukemia cell lines(GI50 at 250 nM-570 nM range), but only a minimal effect in human leukemia cell lines without MLL translocations.TargetsMenin-MLL interaction (Cell-free assay) 14.7 nMIn vitroTreatment of murine bone marrow cells (BMC) transformed with the MLL-AF9 oncogene with MI-503 results in substantial growth inhibition, with half-maximal growth inhibitory concentration (GI50) values of 0.22 µM, measured after 7 days of treatment. The cell growth inhibitory effect of MI-503 is time-dependent, with a pronounced effect achieved after 7-10 days of treatment. MI-503 is also very effective in inducing differentiation of MLL leukemia cells and substantially increases expression of CD11b, a myeloid differentiation marker. These effects are accompanied by reduced c-kit (CD117) expression, a marker associated with leukemia stem cells (LSCs). Treatment with sub-micromolar concentrations of MI-503 also leads to markedly reduced expression of Hoxa9 and Meis1, downstream targets of MLL fusion proteins substantially upregulated in MLL leukemias.In vivoMI-503 has very favorable drug-like properties, including metabolic stability and pharmacokinetic profile in mice. It blocks hematologic tumors in vivo and reduces MLL leukemia tumor burden. MI-503 achieves high level in peripheral blood following a single intravenous or oral dose, while also showing high oral bioavailability (~75%). Prolonged treatment (38 days) with MI-503 induces no toxicity in mice as reflected by no alterations in the body weight and no morphological changes in liver and kidney tissues. MI-503 could substantially improve survival of MLL leukemic mice and does not impair normal hematopoiesis in vivo.Cell Research(from reference)Cell lines：MV4;11 human leukemia cells expressing MLL-AF4 Incubation Time：7days