Paediatric malignant brain tumours are the leading cause of cancer death in children and adolescents. Paediatric ependymoma is the third most common brain tumour in childhood, however the mainstay of therapy has not changed in decades. Surgery and radiotherapy are used to maximise cure, however 1 in 3 children will ultimately relapse. Diffuse intrinsic pontine glioma (DIPG) and diffuse midline glioma (DMG) are high grade brain tumours that are currently incurable. Most patients will survive a median of 9-12 months from diagnosis.

The DART study is a Phase I/II study of Deflexifol®, a co-formulation of a chemotherapy called 5-FU and leucovorin, and is expected to be less toxic and more effective than standard of care versions of these drugs commonly used to treat adult cancers. Children and young adults with refractory or recurrent brain tumours, or patients with newly diagnosed diffuse intrinsic pontine glioma (DIPG)/diffuse midline glioma (DMG) who have completed radiotherapy, will participate in Part A (Phase I) to find the best dose of Deflexifol® for children and young people. Deflexifol® will then be given in Part B (Phase II) to see whether it is an effective treatment for patients with relapsed ependymoma as it has been shown to be effective in early clinical studies.