KO-539 is a novel, once-daily, oral investigational drug candidate targeting the menin-KMT2A/MLL protein-protein interaction for treatment of genetically defined AML patients with high unmet need; In preclinical models, KO-539 inhibits the KMT2A/MLL protein complex and has downstream effects on HOXA9/MEIS1 expression. KO-539 has received Orphan Drug Designation from the U.S. Food and Drug Administration for the treatment of AML.