BAY 2402234 is a novel and selective dihydroorotate dehydrogenase (DHODH) inhibitor. It potently inhibited proliferation of AML cell lines in the sub-nanomolar to low-nanomolar range in vitro and exhibited strong in vivo anti-tumor efficacy in monotherapy in several subcutaneous and disseminated AML xenografts as well as AML patient-derived xenograft (PDX) models.