602710 Disclosed in the use of a sulphonamide compound of formula (I) in the manufacture of a medicament for the treating of tumours. Examples of compounds of formula (I) are: (RS)-S-cyclopropyl-S-(4-{ [4-{ [(1R,2R)-2-hydroxy-1-methylpropyl]oxy} -5-(trifluoromethyl)pyrimidin-2-yl]amino} phenyl)sulfoximide - (RS)-S-(4-{ [4-{ [(1R,2R)-2-hydroxy-1-methylpropyl]oxy} -5-(trifluoromethyl)pyrimidin-2-yl]amino} phenyl)-S-methylsulfoximide - (RS)-S-(4-{ [4-{ [(R)-2-hydroxy-1,2-dimethylpropyl]oxy} -5-(trifluoromethyl)pyrimidin-2-yl]amino} phenyl)-S-methylsulfoximide