JMX0293 is an O-alkylamino-tethered salicylamide derivative compound. JMX0293 maintains good potency against MDA-MB-231 cell line ( IC 50 = 3.38 μM) while exhibiting very low toxicity against human non-tumorigenic breast epithelial cell line MCF-10A ( IC 50 > 60 μM). JMX0293 inhibits STAT3 phosphorylation and contribute to apoptosis in TNBC MDA-MB-231 cells. JMX0293 significantly suppresses MDA-MB-231 xenograft tumor growth in vivo without significant toxicity.