Chronic Myeloid Leukemia is initiated and sustained by BCR-ABL+ leukemia stem cells. Quiescent Leukemic Stem Cells are insensitive to BCR-ABL Tyrosine Kinase Inhibitors. Casiopeinas are novel small molecules with anticancer activity. Casiopeina III-Ea possesses antileukemic activity in vitro with minimal effects on normal cells.