MI-463 is a potent and orally bioavailable inhibitor of the menin-mLL interaction (IC50: 15.3 nM).

Treatment of murine bone marrow cells (BMC) transformed with the mLL-AF9 oncogene with MI-463 results in substantial growth inhibition (GI50: 0.23 μM). MI-463 is effective in inducing differentiation of MLL leukemia cells. Treatment with sub-micromolar concentrations of MI-463 also leads to markedly reduced expression of Hoxa9 and Meis1.

MI-463 shows substantial survival benefit in mouse models of MLL leukemia. It has very favorable druglike properties, including metabolic stability and PK profile in mice. MI-463 achieves high level in peripheral blood following a single intravenous or oral dose, while also showing high oral bioavailability (45%). MI-463 induces strong inhibition of tumor growth with once-daily intraperitoneal (i.p.) administration. The expression of mLL fusion protein target genes, HOXA9 and MEIS1, is significantly reduced upon treatment with MI-463.

Leukemia cells are treated with MI-463 or 0.25% DMSO and cultured at 37 °C for 7 days. Media is changed on day 4, viable cell numbers are restored to the original concentration and MI-463 is re-supplied. MTT cell proliferation assay kit is then employed, and plates are read for absorbance at 570 nm using a microplate reader.

For efficacy studies in MV4;11 subcutaneous xenograft mice model, 5×10^6 cells are injected into the 4-6 week old female BALB/c nude mice. Treatment is started when the tumor size reached ~100 mm^3. Vehicle (25% DMSO, 25% PEG400, 50% PBS) or MI-463 are administrated once daily at designated doses using i.p. injections.