The Discovery of Cenobamate: A Drug with High Efficacy in Drug-Resistant Epilepsy

Cenobamate is a novel alkyl-carbamate antiseizure medication (ASM) that represents a major breakthrough in the treatment of drug-resistant epilepsy, particularly focal seizures. Unlike other ASMs, cenobamate achieves seizure freedom in up to one third of patients with focal drug-resistant epilepsy-a response not observed with other therapies. Herein, we describe the chemocentric and phenotypic screening strategy employed by one of us (Yong Moon Choi) while at SK Biopharmaceuticals and how cenobamate was developed by optimizing earlier alkyl-carbamates such as carisbamate and felbamate. We discuss how the incorporation of a tetrazole moiety likely played a significant role in its successful development. Cenobamate was found to display potent broad-spectrum activity in diverse disease-relevant rodent models, including maximal electroshock, pentylenetetrazole, kindling, and lithium-pilocarpine-induced status epilepticus. When compared to 12 other ASMs, it ranked highest across four models of difficult-to-treat focal seizures. We discuss how the two known molecular activities of cenobamate, i.e., positive allosteric modulation of GABA_A receptors via a non-benzodiazepine site and inhibition of persistent sodium currents (I_NaP), may contribute to its clinical efficacy and how pharmacokinetic/pharmacodynamic modeling confirmed that the effective brain concentrations of cenobamate align with clinically relevant plasma concentrations observed in seizure-free patients. The discovery of cenobamate has significant implications for future ASM development. It validates phenotypic screening as a powerful tool for identifying first-in-class central nervous system therapeutics and highlights the value of chemocentric optimization using known scaffolds. The predictive utility of specific preclinical models-especially kindling and lithium-pilocarpine-suggests that future ASM discovery should prioritize models that better mimic pharmacoresistant epilepsy. The dual mechanisms of cenobamate may serve as a blueprint for designing ASMs with synergistic actions. Approval of cenobamate represents a paradigm shift in epilepsy treatment and offers a promising framework for discovering more effective therapies for drug-resistant epilepsy.