Abstract: A polymeric drug, in which a cancerostatic connected via spacers containing hydrolytically cleavable hydrazone bonds is bound to a water-soluble polymeric carrier prepared on the basis of a N-(2-hydroxypropyl)methacrylamide copolymer, wherein the structure of the polymeric drug consists of the main chain of N-(2-hydroxypropyl)methacrylamide carrying the cancerostatic and another chain of N-(2-hydroxypropyl)methacrylamide—a graft, which may also carry a cancerostatic, said grafts being bound to the main chain by a bond that is stable in the body and/or by a bond cleavable in the body, especially by an oligopeptide spacer selected from the series of GlyLeuGly, GlyPheGly, GlyPheLeuGly and GlyLeuPheGly, and a method of its preparation.