SK Biopharmaceuticals Announces Top-Line Results from Phase 3 Trial of Cenobamate for Generalized Epileptic Seizures

Key Endpoints Achieved
Expansion of Cenobamate Indications Shows Positive Outlook

On September 16, SK Biopharmaceuticals announced that it has obtained positive top-line results from a Phase 3 clinical trial evaluating cenobamate (U.S. brand name XCOPRI®), its innovative anti-epileptic drug, for the treatment of primary generalized tonic-clonic (PGTC) seizures in adolescents and adults as part of its efforts to expand the drug's indications.

Cenobamate is currently approved and prescribed for adult patients with partial-onset seizures. Based on the results of this clinical trial, the company expects to expand the indication to include adolescent and adult patients with primary generalized tonic-clonic seizures.

This Phase 3 trial was conducted at 122 clinical sites across 12 countries, including the United States and South Korea, and evaluated the efficacy and safety of cenobamate compared to placebo in 169 patients aged 12 years and older with primary generalized tonic-clonic seizures.

The clinical results showed that, during the double-blind treatment period, adjunctive cenobamate therapy reduced the frequency of PGTC seizures by 71.9% from baseline in the cenobamate group, compared to a 39.6% reduction in the placebo group. This demonstrated a statistically significant reduction in the primary endpoint (p=0.003). In terms of safety, the most common treatment-emergent adverse events (TEAEs) were reported in 60% of the cenobamate group and 53% of the placebo group. Most reported adverse events were mild to moderate in severity, confirming the overall safety and tolerability of cenobamate. SK Biopharmaceuticals plans to present detailed clinical results at the 2025 American Epilepsy Society (AES) Annual Meeting in December this year.

PGTC seizures are a representative type of generalized seizure and are known to be a serious form of seizure that increases the risk of seizure-related injuries and sudden unexpected death in epilepsy. However, treatment options specifically approved for efficacy in PGTC seizures are limited, so these clinical results are expected to help address unmet medical needs. Based on these achievements, SK Biopharmaceuticals plans to proceed with the regulatory submission process to the FDA for the additional PGTC indication.

SK Biopharmaceuticals CEO Lee Donghoon stated, "Since its launch, cenobamate has established itself as an innovative new drug in the global market. The significance of these clinical results lies in our ability to offer new treatment opportunities to more patients, and, in particular, the broad efficacy of cenobamate has now been clinically proven. We expect cenobamate's position in the global anti-epileptic drug market to be significantly strengthened going forward."