NCMP-07. Impact of clobazam on seizure control and antiseizure medication reduction in refractory brain tumor related epilepsy

BACKGROUND Approximately 60% of patients with gliomas suffer from medically refractory brain tumor related epilepsy (BTRE), requiring two or more antiseizure medications (ASMs)(Seidel, 2022). Seizures, in addition to the use of multiple ASMs, are associated with lower quality of life in patients (Terman, 2020; Iannou 2022). Clobazam is an add-on therapy which can be effective in refractory BTRE (Van der Meer 2023, Brahmbhatt 2021). This study evaluates the response of patients with refractory BTRE to clobazam and the potential to reduce other ASMs. METHODS This single study retrospective analysis evaluates 48 patients from a single institution diagnosed with a glioma who received clobazam at some point in their treatment between June 2017- June 2024. Data was collected, including seizure type, frequency, and ASMs, at 6 months and last documented follow-up visit. RESULTS At 6 months on clobazam, 68.8% (33/48) of patients were seizure free, and at the final timepoint (average 26.8 months), 60.4% (29/48) were seizure free. At 6 months, 33.3% (16/48) of patients were able to decrease their total other ASMs while maintaing seizure freedom. Of those who did not decrease the number of other ASMs taken, 21.9% (7/32) were able to reduce the dosage of other ASMs. At the final timepoint, 50.0% (24/48) of patients decreased the number of other ASMs they were taking. CONCLUSIONS Despite failing other ASMs, the majority of patients who took clobazam became seizure free. While seizure freedom is the overall goal, reducing side effects is equally important for quality of life. After initiating clobazam, number and dosages of concurrent ASMs may also be reduced while maintaining seizure freedom or a reduced seizure frequency.