10305- ACT-17 EFFECTIVENESS OF DABRAFENIB AND TRAMETINIB IN PATIENTS WITH GLIOMA WITH MUTATION OF BRAF V600E: A SINGLE CENTER ANALYSIS.

Abstract BACKGROUND In tumor cells, Dabrafenib (DB) acts on the mutated BRAF itself, and Trametinib (TR) acts on MEK and suppresses cell proliferation, and the combination of the two drugs is used for melanoma with BRAF mutations, non-small cell lung cancer, and advanced or recurrent solid tumors (excluding colon and rectal cancer) that are difficult to treat as standard. It has been approved in Japan by November 2023. In this study, we analyzed a case of using DB+TR for glioma at our center. METHODS DB+TR was applied to gliomas treated at our center from January 2018 to December 2023. RESULTS There were 10 patients, aged 32.7 years, and 3 males and 7 females. Pathological diagnoses was GBM 2, epithelioid GBM 2, anaplastic PXA 2, and anaplastic astrocytoma, glioneural tumor, gliosarcoma, and neuroepithelial tumor 1 respectively. IDH gene wild type and BRAF V600E mutation were observed in all cases. TERT mutations were observed in three C228T mutations and one C250T mutation. In 7 patients, temozolomide + radiotherapy 60Gy/30fraction was given as initial treatment. There were 9 cases in which DB+TR was used at the time of recurrence, and 1 case in which DB+TR was used in the initial treatment. As an adverse event (AE), DB+TR administration was discontinued in 1 case of intratumoral hemorrhage and 2 cases of skin rash. Skin rash was observed in other cases, but DB+TR administration could be continued with symptomatic treatment. The best effects were CR 5, PR 1 and SD 4. The median time from DB+TR use to recurrence was 21.3 (5 to 78.9) months. There were four deaths, and the median survival after discontinuation of DB+TR was 7.2 months (1.27 to 12.8). DISCUSSION/CONCLUSION For recurrent gliomas with BRAF V600E mutations, DB+TR showed good outcomes, although administration was discontinued due to AEs in three cases.