Abstracts

This is a Late Breaking abstract

Rationale: Cenobamate (CNB) is a new Anti-Seizure Drug (ASD). Since, 2020, early CNB access program in France permit to treat adults’ patients with Drug Resistant Focal Seizure DRFS. We report results of a monocentric retrospective study in adult patients presenting highly DRFSs. Aim of this study, is to seek for responders (> 75% reduction of focal motor and impaired awareness seizures) in patients with rare syndrome and/or etiologies using ILAE 2017-2022 classifications. _x000D_ _x000D_ Methods: Patients over 18 years with DRFS (with at least four motor or unaware seizures a month) were retrospectively include from Nov 2020-March. Inclusion criteria were: 1 to 4 concomitant ASD, ability of patients and/or care givers to record seizure a diary. Seizures, Epilepsies, Syndromes and Etiologies were classified. Association of focal and generalized seizures was not an exclusion criterion. Effectiveness of CNB on generalized seizures types (atypical absences, spasm, myoclono-atonic.) were evaluated. Concomitant ASDs were adapted (Clinical Pharmacist) in order to anticipate potential side effects. Patients should have at least 3 months of follow-up after a one-month titration to 200mg. Following titration, if needed CNB could be reduced to 100mg or increased up to 300mg or 400mg. Seizures responders’ (> 75% reduction of seizure of motor or unaware seizures) were defined on the last 3 months treatment period compare 3 months retrospective base line. Minor and major sides effects and reason drop out were analyzed._x000D_ _x000D_ Results: Among 56 patients, 45 met the inclusion criteria, 5 dropped out of the study mainly during titration for side effects (dizziness, somnolence, vertigo, and one minor allergy). Twenty (20/45, 44%) patients were responders (> 75% reduction of seizure).
- Etiologies were respectively in Responder and Non-Responder: 11/13 structural; 8/9 unknown, 1/7 genetic, 2/3 Inflammatory-immune.
- Specific Etiologies: Non-Responder: One with: polymicrogyria, DNET, hippocampal sclerosis, Invdup15, tuberous sclerosis, trisomy 8, KCNT1, 22Q13 Responder: One with cavernous angioma, arteriovenous malformation, cortical dysplasia, hippocampal sclerosis, polymicrogyria.
- Syndromes were respectively in Responder and Non-Responder: FIRES 0/3, Rasmussen 2/0, epilepsy with epileptic Spasm 1/0, Lennox-Gastaut 0/1._x000D_ _x000D_ Conclusions: CNB was well tolerated. Patients with Genetic etiology are not the best responders in comparison with Structural or Unknown etiologies.  For Inflammatory or Dysimmune etiologies: 3 patients with FIRES were non responders, but 2 patients with Rasmussen were improved. About additional seizures types: atypical absence does not seem to be improve by CNB. Spasm persisting in adulthood are infrequent and could occur in Focal epilepsy, one patient with highly DRE was almost seizure free. This retrospective monocentric pilot study has several biases but suggest the need of using 2017-2022 Classification in order to be confirm._x000D_ _x000D_ Funding: University of Strasbourg