SK Biopharmaceuticals Co Ltd, a South Korea-based pharmaceutical company, announced on Wednesday that it has submitted a supplemental New Drug Application (sNDA) to the US Food and Drug Administration (FDA) seeking approval of cenobamate (US brand name: XCOPRI) for the treatment of primary generalised tonic-clonic seizures (PGTC) and an expansion of the existing focal-onset seizure (FOS) indication to include paediatric patients.

The sNDA is supported by positive results from a global Phase 3 trial evaluating cenobamate in patients 12 years of age and older living with PGTC seizures. The trial enrolled 169 patients across 122 sites in 12 countries, including the USA, South Korea and countries in Europe.

In the trial, patients treated with cenobamate experienced a median 71.9% reduction in PGTC seizure frequency from baseline compared with a 39.6% reduction among patients receiving placebo, a statistically significant difference. Most reported adverse events were mild to moderate, and the safety findings were consistent with the known safety profile of cenobamate, with no new safety signals observed.

If approved by the FDA, the new indication would expand the use of cenobamate beyond its current indication for focal-onset seizures in adults, and provide an additional treatment option for eligible patients with PGTC seizures. The PGTC submission is part of SK Biopharmaceuticals' broader effort to evaluate cenobamate across additional patient populations and formulations.

SK Biopharmaceuticals also submitted a separate sNDA to the FDA in October seeking to expand the existing focal-onset seizure (FOS) indication to paediatric patients. The company confirmed cenobamate's safety in clinical trials in paediatric patients with FOS and is pursuing an expansion of the eligible age range on that basis.

In March, the company submitted a New Drug Application (NDA) to the FDA for an oral suspension formulation of cenobamate. This formulation would provide an alternative for patients who have difficulty swallowing tablets and was also used in the paediatric clinical trial programme.