Antileukemic activity of HQP1351 was first examined using AML cell lines MV-4-11 and MOLM-13, which harbor FLT3-internal tandem duplication (FLT3/ITD) mutations…In particular, treatment of subcutaneous MV-4-11 xenograft tumors in nude mice with HQP1351 10 mg/kg significantly suppressed tumor growth, with a tumor growth inhibition (TGI) of 72.4%...This antitumor effect was potentiated when APG-2575 was combined with HQP1351, resulting in a TGI of 97.2%...The results provide scientific rationale for clinical development of HQP1351 combined with APG-2575 in patients with FLT3-ITD-mutant AML.