CNS malignancy is treated in a subject suffering from a CNS malignancy by administering to the subject an antisense oligonucleotide having a sequence of bases that is complementary to portions of both the gene encoding IGFBP-2 and the gene encoding IGFBP-5, and which is of sufficient length to act as an inhibitor of the effective amount of IGFBP-2 and IGFBP-5, in an amount effective to reduce effective levels of IGFBP-2 and IGFBP-5 in cells of the CNS malignancy.