A method of treating lymphoblastic leukemia, acute myeloid leukemia, BCR-ABL positive acute lymphoblastic leukemia or CD34 positive acute myeloid leukemia comprising the step of administering to a patient a pharmaceutically acceptable amount of a composition comprising a thienotriazolodiazepine compound according to Formula (1) as a solid dispersion wherein X is a halogen, R1 is C1-C4 alkyl, R2 is C1-C4 alkyl, a is an integer of 1-4, R3 is C1-C4 alkyl, C1-C4 hydroxyalkyl, C1-C4 alkoxy, phenyl optionally having substituent(s), or heteroaryl optionally having substituent(s), a pharmaceutically acceptable salt thereof or a hydrate thereof and a pharmaceutically acceptable polymer. In one embodiment, the pharmaceutically acceptable polymer is HPMCAS.
