RecruitingPhase 3Drug trialEffect of Metformin on Behaviour and the Brain in Children Treated for a Brain TumourThe efficacy of treatment with metformin for promoting cognitive recovery and brain growth in children/adolescents treated for a brain tumour will be investigated in a multi-site Phase III randomized double-blind placebo-controlled parallel arm superiority trial. Specifically, in children/adolescents aged 7 years to 21 years and 11 months who have completed treatment for a brain tumour, is oral administration of metformin for 16 weeks associated with greater improvement of cognitive function and brain growth compared to placebo administered for 16 weeks?