There is a clear medical need for new therapies, particularly for relapsed solid tumors, specifically brain tumors. Although pre-clinical data from our group and others suggests DNA demethylase inhibitors to be promising therapies for high risk ependymoma, medulloblastoma and ETMR (embryonal tumor with multilayered rosettes), 5'azacitidine monotherapy has been disappointing in clinical studies of adult solid tumours. Previous studies have suggested that platinum therapy can be effectively combined with azacitidine therapy and based on adult studies, maximum demethylation occurs approximately 5-10 days after treatment with 5'azacitidine. As such combination of azacitidine and carboplatin is a rationale therapy for several pediatric brain tumours, particularly those with a hypermethylated phenotype.