A liquid pharmaceutical composition for use in the treatment of acute lymphoblastic leukaemia (ALL) comprising 6-mercaptopurine or a salt, hydrate or solvate thereof and a pharmaceutically-acceptable excipient, wherein the composition is a suspension for oral administration, a kit of parts for the accurate dosing and administration of the liquid pharmaceutical composition, and a method for the treatment of ALL in a human patient comprising administration of a therapeutically effective amount of the liquid pharmaceutical composition.
