DS-M1 demonstrates significant survival benefit...in patient-derived xenograft (PDX) models of MLL1-r or NPM1-mu acute leukemia. These data indicate that DS-M1 has a high potency as an antitumor drug with the potential to provide survival advantage in acute leukemia patients with MLL-r and NPM1-mu. MLL1-r pediatric B-ALL-PDX mice treated with 50 mg/kg bid for 28 days and NPM1-mu AML-PDX mice treated with 100 mg/kg bid for 35 days were all survived (ILS >254% and >300%) without any detectable leukemic blast cells in bone marrow at 120 and 60 days after cessation of therapy, respectively.