Paramus, New Jersey, United States, November 4, 2026
SK Biopharmaceuticals Co., Ltd. has submitted a supplemental New Drug Application (sNDA) to the U.S. Food and Drug Administration (FDA), seeking approval to expand the use of cenobamate, marketed in the United States as XCOPRI®, to treat primary generalized tonic-clonic (PGTC) seizures in patients aged 12 years and older. The application is supported by positive findings from a global Phase 3 clinical trial evaluating the efficacy and safety of cenobamate in people living with PGTC seizures. In the study, patients receiving cenobamate experienced a median reduction of 71.9% in seizure frequency from baseline, compared with a 39.6% reduction among those receiving placebo. The difference between the treatment groups was statistically significant. The regulatory submission represents an important milestone in SK Biopharmaceuticals’ strategy to expand cenobamate’s therapeutic potential and provide additional treatment options for people living with epilepsy.
Phase 3 Trial Demonstrates Significant Seizure Reduction
The sNDA is supported by results from a global Phase 3 clinical trial (NCT03678753) involving 169 patients aged 12 years and older with primary generalized tonic-clonic seizures. The study was conducted across 122 clinical sites in 12 countries, including the United States, South Korea and several European countries. The trial evaluated the efficacy and safety of cenobamate compared with placebo in patients with PGTC seizures. According to the company, participants treated with cenobamate experienced a median 71.9% reduction in PGTC seizure frequency from baseline, while participants receiving placebo experienced a median reduction of 39.6%. The difference was statistically significant, with a reported p-value of 0.003. These findings suggest that cenobamate may provide meaningful seizure-frequency reduction for patients with this form of epilepsy. PGTC seizures involve abnormal electrical activity affecting both sides of the brain from the onset. They can cause loss of consciousness, muscle stiffening and repeated involuntary movements, and may create substantial risks for patients’ safety and daily functioning. The safety findings were also encouraging. Most reported adverse events were described as mild to moderate in severity, and the overall safety profile was consistent with previously established clinical experience with cenobamate. The company reported that no new safety signals were observed in the Phase 3 study.
FDA Application Seeks Broader Epilepsy Treatment Access
Cenobamate is an antiseizure medication discovered and developed by SK Biopharmaceuticals. It is currently approved in the United States under the brand name XCOPRI® for the treatment of focal-onset seizures in adults. The latest sNDA seeks to extend its use to a different seizure type, primary generalized tonic-clonic seizures, in patients aged 12 years and older. The proposed expansion could broaden the population eligible for treatment if the FDA determines that the submitted clinical evidence supports approval. This is particularly important because epilepsy includes several seizure types that differ in their underlying neurological activity, clinical presentation and treatment requirements. The new application is part of a broader lifecycle-development strategy for cenobamate. In addition to the PGTC submission, SK Biopharmaceuticals has submitted a separate sNDA seeking to expand the existing focal-onset seizure indication to include pediatric patients. The company is also pursuing development of an oral suspension formulation to provide an alternative administration option for patients who may have difficulty swallowing tablets. These are separate regulatory initiatives, and the pediatric focal-onset application should not be confused with the current PGTC indication expansion.
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SK Biopharmaceuticals Advances Cenobamate Development
SK Biopharmaceuticals continues to invest in expanding the clinical and commercial potential of cenobamate through additional indications, patient populations and formulations. The company’s U.S. subsidiary, SK Life Science, Inc., supports the commercialization and development of XCOPRI in the American market. According to Donghoon Lee, Chief Executive Officer of SK Biopharmaceuticals, the latest submission reflects the company’s continued efforts to evaluate cenobamate across additional seizure types, age groups and formulations, with the aim of providing more treatment options for people living with epilepsy. The FDA submission does not mean that the new indication has been approved. The agency must review the application and supporting clinical evidence before making a regulatory decision. Until approval is granted, the existing U.S. indication for cenobamate remains limited to focal-onset seizures in adults. Overall, the Phase 3 results and FDA submission represent an important milestone in cenobamate’s clinical development program. If approved, the expanded indication could offer an additional treatment option for eligible patients aged 12 and older with PGTC seizures. The FDA’s review and further clinical evidence will determine the medicine’s future role in managing this form of epilepsy.
Source: SK Life Science press release
