The invention relates to quinazoline derivatives of formula (I), wherein m is an integer from 1 to 3; R.sup.1 represents halogeno or C.sub.1-3alkyl; X.sup.1 represents --O--; R.sup.2 is selected from one of the following three groups: 1) C.sub.1-5alkylR.sup.3 (wherein R.sup.3 is piperidin-4-yl which may bear one or two substituents selected from hydroxy, halogeno, C.sub.1-4hydroxyalkyl and C.sub.1-4alkoxy; 2) C.sub.2-5alkenylR.sup.3 (wherein R.sup.3 is as defined hereinbefore); 3) C.sub.2-5alkynylR.sup.3 (wherein R.sup.3 is as defined hereinbefore); and wherein any alkyl, alkenyl or alkynyl group may bear one or more substituents selected from hydroxy, halogeno and amino; and salts thereof, processes for their preparation, pharmaceutical compositions containing a compound of formula (I) or a pharmaceutically acceptable salt thereof as a active ingredient. The compounds of formula (I) and the pharmaceutically acceptable salts thereof inhibit the effects of VEGF, a property of value in the treatment of number of disease states including cancer and rheumatoid arthritis.