After 8 treatment cycles, Cohort 1 (recently diagnosed high-grade glioma) and Cohort 3 (intrinsic brain stem tumour) patients will be evaluated for treatment response and if there is disease progression they will be withdrawn from the trial and will receive conventional treatment with radiotherapy together with temozolomide (Stupp 2005). Patients with disease progression at any time during the trial will also be withdrawn. Patients who respond will continue until completing the 16 cycles of irinotecan and cisplatin at the end of which they will continue with conventional therapy. Cohort 2 (recurrent high-grade glioma) and Cohort 4 (high risk low-grade glioma) patients will also be evaluated after 8 cycles and if there is disease progression they will be withdrawn from the trial, if not they will complete the full 16 cycles.