Diffuse intrinsic pontine glioma (DIPG) is a surgically incurable paediatric brain tumour for which no effective therapy has been developed. A key challenge in developing new treatments for DIPG has been the lack of available tumour material. However, the introduction of autopsies/biopsies in the past five years has allowed the establishment of primary DIPG neurosphere cell cultures. In collaboration with Stanford Institute (USA) and St John of Hope Hospital (Spain), we have established eight DIPG neurosphere cultures and optimised their culture conditions to allow maintenance of a high proportion of highly resistant cancer stem cells. This enabled us to perform the first high throughput drug screen for DIPG. Over 3,500 clinically relevant compounds were screened for their ability to inhibit DIPG cell proliferation using alamar blue assays. Consistent with clinical results, the vast majority of compounds tested, which included active chemotherapeutic agents, showed no effect against the DIPGs. However, 30 promising candidates with diverse mechanisms of action were identified that result in DIPG cell viability of < 10% compared with control. These are currently being further evaluated against a panel of DIPGs by in vitro cytotoxicity assays in order to isolate the most effective compounds, prior to in vivo testing. Two of the primary DIPG cultures were used to develop in vivo orthograft models of DIPG. Intracranial stereotactic injections of tumour cells were performed into the brainstem of NOD/SCID mice. The mice developed highly specific neurological symptoms in such as ataxia, circling and head tilting, indicating tumour formation. The presence of highly proliferative DIPG tumours in the brainstem were confirmed in both orthograft models using immunohistochemistry staining for Ki67. The histopathological appearance was consistent with that seen in DIPG tumours in children. Mice developed tumours within 12 weeks of injection, facilitating the implementation of this model for therapeutic drug testing. Our findings provide a strong foundation for further research to develop effective therapies for children with DIPG.