Successful treatment of an adult patient with diffuse midline glioma employing olaparib combined with bevacizumab.

Diffuse midline gliomas (DMGs), which are malignant, fast-growing and entail a poor prognosis, are a rare subtype of glial tumor. DMGs harboring H3 K27-mutation are a novel entity with a poorer prognosis than the H3 wildtype and are categorized as a grade IV glioma. Histone-mutated DMGs characterized by a midline location occur more commonly in children and less frequently in adults. Considering the DMG treatment is limited, there is an urgent need for effective therapeutic strategies. Olaparib is a poly-adenosine diphosphate-ribose polymerase inhibitor, which has been reported to inhibit glioma in preclinical and clinical trials. Olaparib plus bevacizumab has been successfully used in ovarian cancer. However, the application of olaparib in DMGs has not been reported yet. Herein, we firstly reported that an adult DMG patient benefited from olaparib combined with bevacizumab and achieved complete remission. The duration of response and overall survival was 8 months and 16 months respectively. This report provides a promising treatment option for patients with DMG.