A method of treating neuroblastoma in a mammal comprising the step of: administering a pharmaceutical acceptable amount of a thienotriazolodiazepine compound being represented by the following Formula (1): wherein R1 is alkyl having a carbon number of 1-4, R2 is a hydrogen atom a halogen atom or alkyl having a carbon number of 1-4 optionally substituted by a halogen atom or a hydroxyl group, R3 is a halogen atom phenyl optionally substituted by a halogen atom, alkyl having a carbon number of 1-4, alkoxy having a carbon number of 1-4 or cyano— NR5— (CH2)m— R6 wherein R5 is a hydrogen atom or alkyl having a carbon number of 1-4, m is an integer of 0-4, and R6 is phenyl or pyridyl optionally substituted by a halogen atom or -NR7— CO— (CH2)n— R8 wherein R7 is a hydrogen atom or alkyl having a carbon number of 1-4, n is an integer of 0-2, and R8 is phenyl or pyridyl optionally substituted by a halogen atom, and R4 is — (CH2)a— CO— NH— R9 wherein a is an integer of 1-4, and R9 is alkyl having a carbon number of 1-4 hydroxyalkyl having a carbon number of 1-4 alkoxy having a carbon number of 1-4 or phenyl or pyridyl optionally substituted by alkyl having a carbon number of 1-4, alkoxy having a carbon number of 1-4, amino or a hydroxyl group or— (CH2)b— COOR10 wherein b is an integer of 1-4, and R10 is alkyl having a carbon number of 1-4, or a pharmaceutically acceptable salt thereof or a hydrate or solvate thereof.La présente invention concerne une méthode permettant de traiter un neuroblastome chez un mammifère, comprenant une étape qui consiste à administrer une quantité pharmaceutiquement acceptable dun composé thiènotriazolodiazépine de formule (1) dans laquelle R1 désigne un groupe alkyle ayant 1 à 4 atomes de carbone R2 désigne un atome dhydrogène, un atome dhalogène ou un groupe alkyle ayant 1 à 4 atomes de carbone facultativement substitués par un atome dhalogène ou un groupe hydroxyle R3 désigne un atome dhalogène, un groupe phényle facultativement substitué par un
