The present application relates to compounds of formula (I), which inhibit FLT3. The present application further relates to a composition, preferably pharmaceutical composition, comprising a compound of formula (I) or a pharmaceutically acceptable salt thereof and comprising a pharmaceutically acceptable excipient and/or carrier. The present application also relates to a compound of formula (I) or composition thereof for use in medicine. The present application also relates to a compound of formula (I) or composition thereof for use in a method of preventing or treating cancer, preferably blood cancer, more preferably leukemia, even more preferably acute myeloid leukemia (AML). Furthermore, the present application relates to a method of preparing a compound of formula (I).