Cenobamate for the treatment of focal epilepsy

Focal-onset or partial seizures are localized to a specific brain area or areas of the cerebral hemisphere. Cenobamate (CNB, Xcopri, YKP-3089; SK Life Science) is a recent U.S. Food and Drug Administration (FDA)-approved drug for the treatment of focal-onset seizures in the adult population. CNB has demonstrated broad-spectrum efficacy in alternative preclinical models of epilepsy. The molecule exerts an antiseizure effect due to its dual mechanism of action: besides inhibiting the voltage-gated persistent component of the sodium currents, CNB is additionally an allosteric GABA(A) channel modulator in a non-benzodiazepine fashion. The superior clinical effect of this molecule over placebo in reducing seizure frequency may be observed after 2 weeks following a starting oral dose of 50 mg/day. The drug can be titrated up to a maximum daily maintenance dose of 400 mg/day. CNB has mild to moderate side effects. During initial development, a critical drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome was noticed in 3 patients. However, the DRESS effect was not observed in the large C021 safety study involving 1,347 patients, suggesting a maximum potential risk of no more than 0.3%. The present monograph describes the background, preclinical and clinical pharmacology, indication and safety of CNB for the treatment of partial/focal seizures.