Aberrant DNA methylation is frequently observed in many pediatric solid tumors, but in particularly several entities such as ependymoma, medulloblastoma, embryonal tumor with multilayered rosettes, atypical/teratoid rhabdoid tumor, neuroblastoma and wilm's tumor have promoter hypermethylation. Treatment with DNMTi (DNA methyltransferase inhibitors) agents such as 5-azacytidine has been shown to be safe and efficacious in adult myelodysplastic syndromes, causing significant decreased DNA methylation in blood, with maximum effect at day 15 of each cycle. However, monotherapy with DNMTi has been shown to result in resistance in leukamia's and efficacy in solid tumours is limited. Synergy between DNMTi and platinum agents has shown promise in pre-clinical models including pediatric ependymoma, and in addition, the combination of demethylating agents with carboplatin has provided promising results in platinum resistant ovarian cancers. However, this approach has not been applied to pediatric solid malignancies, which are attractive targets due to their frequent epigenetic dysregulation.