The purpose of the present invention is to provide a drug that is capable of effectively inhibiting adhesion activity, growth, and engraftment of cancer cells, using an oligodeoxynucleotide (ODN) in which phosphodiester bonds are phosphorothioated (S-configured). Adhesion activity, growth inhibitory capacity, and engraftment inhibitory capacity of cancer cells are rapidly improved as a result of S-configured ODN being formed into a composite with a polysaccharide having a β-1,3-glucan backbone.
