MI-503 is an efficient and selective Menin-MLL inhibitor with an IC50 of 14.7 nM. In human MLL leukemia cell lines, MI-503 has a significant growth inhibition effect (GI = 250 nM-570 nM).

Menin-MLL:4.7 nM (cell free)

方法：用 MLL-AF9 和 Hoxa9/Meis1 (HM-2) 转化的小鼠骨髓细胞 (BMC) 用 MI-503 (0-5 µM) 处理 7 天，通过 MTT assay 检测活力。
结果：用 MI-503 处理用 MLL-AF9 癌基因转化的 BMC 导致了显著的生长抑制，治疗 7 天后测得的 GI50 值为 0.22 µM。[1]
方法：过表达野生型 menin 和三种突变蛋白的 AGS 细胞用 MI-503 (1 µmol/L) 处理 48 h，通过 Western Blot 检测靶点蛋白表达水平。
结果：MI-503 增加了核蛋白的表达，在 R516fs 和 E235K 突变体中观察到的效果最大。[2]

方法：为检测体内抗肿瘤活性，将 MI-503 (60 mg/kg，25% DMSO+25% PEG400+50% PBS) 腹腔注射给携带 MV4;11 异种移植物的 BALB/c nude 小鼠，每天一次，持续 20 天。
结果：MI-503 能强烈抑制肿瘤生长。MI-503 治疗导致 MV4;11 减少 80% 以上，2 只小鼠的肿瘤体积和肿瘤完全消退。[1]

Leukemia cells are treated with MI-503 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-503 are 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 compounds (MI-463 or MI-503) are administrated once daily at designated doses using i.p. injections.