Abstract: The present invention relates to an inhibitor against the stem cells of chronic myeloid leukemia (CML), a pharmaceutical composition for the treatment of CML having preventive effect on CML recurrence, a method of preventing CML recurrence, and a method of assessing the efficacy of treatment with a drug in a patient with CML, including a step of determining the expression level of latexin.

Abstract: [Problems] The object is to provide a compound as a therapeutic or prophylactic agent for TKI-resistant CML to replace the injection “Dacogen®” which has been clinically used as a therapeutic agent for high-risk myelodysplastic syndrome and acute myeloid leukemia. The said compound has remarkable stability against cytidine deaminase, a hydrolytic enzyme, and is absorbed in vivo even by oral administration, incorporated into the biosynthesis route of nucleic acid, and exhibits the effect of inhibiting DNA methyltransferase (DNMT).