[Edaily Reporter NA EUN-KYUNG ] Donga ST(170900)(Dong-A ST) has launched “Xcopri” (active ingredient: cenobamate), an epilepsy treatment developed by SK BIOPHARMACEUTICALS(326030), in the domestic market. It is expected to serve as a new treatment option for adult epilepsy patients whose seizures are not adequately controlled by existing antiepileptic drugs.

Donga ST announced on the 2nd that it has launched “Xcopri” tablets—the 41st domestically developed new drug—in South Korea, with coverage under the National Health Insurance. Xcopri received marketing authorization from the Ministry of Food and Drug Safety last November. It was approved as an adjunctive therapy, to be used in combination with other medications, for the treatment of partial seizures in adult epilepsy patients whose seizures are not adequately controlled by existing antiepileptic drugs.

Epilepsy is a chronic neurological disorder characterized by recurrent seizures caused by abnormal electrical signals in brain neurons. Seizures manifest in various forms, including convulsions, loss of consciousness, abnormal sensations, and behavioral changes. It is estimated that there are approximately 360,000 patients receiving treatment in South Korea, and about 30% of them are reported to suffer from drug-resistant epilepsy, in which seizures persist despite adequate medication.

A key feature of Excofry is that it suppresses excessive excitation of brain neurons through two distinct mechanisms. It inhibits the sustained current of sodium channels—which transmit electrical signals in neurons—while simultaneously enhancing the action of GABA, an inhibitory neurotransmitter. This approach reduces neuronal excitation while strengthening the signals that suppress seizures.

Lacosamide, a third-generation antiepileptic drug, promotes the inactivation of sodium channels, while perampanel blocks AMPA receptors involved in excitatory neurotransmission. Excorpri differs in that it acts simultaneously on both sodium channels and GABA receptors. However, this difference in mechanism does not guarantee superior clinical efficacy compared to existing treatments.

In clinical trials, Xcopri demonstrated not only a reduction in seizure frequency but also “complete seizure freedom”—a period during which no seizures occurred at all. The global clinical trial (Study 017), which served as the basis for approval by the U.S. Food and Drug Administration (FDA), enrolled 437 adult patients whose seizures were not controlled by existing antiepileptic drugs.

In that trial, seizure frequency in the 200 mg and 400 mg cenobamate groups decreased by approximately 55% compared to baseline, respectively. Notably, the proportion of patients who experienced no seizures at all during the 12-week maintenance period was 11% in the 200 mg group and 21% in the 400 mg group—higher than the 1% observed in the placebo group.

Efficacy was also confirmed in an Asian Phase 3 clinical trial (Study 035) involving 519 adult patients with focal seizures from South Korea, China, and Japan. During the 6-week maintenance period, the complete seizure freedom rate was 30.1% in the 200 mg group and 52.4% in the 400 mg group, both exceeding the 2.6% rate in the placebo group. However, direct comparison of the figures is difficult because the two trials differed in patient demographics and evaluation periods.

Excofry is an oral medication taken once daily. To reduce the risk of serious hypersensitivity reactions, such as rash, treatment should begin at a low dose and be gradually increased. Since dizziness and drowsiness were reported as major adverse reactions in clinical trials, prescribing should take into account the patient’s condition and concomitant medications.

Donga ST expects that coverage under the National Health Insurance program will reduce the financial burden on patients whose seizures were difficult to control with existing medications and improve access to treatment.

Donga ST previously signed an agreement with SK BIOPHARMACEUTICALS in January 2024 to introduce Excofry in 30 countries, including South Korea, East and Southeast Asia, Russia, Australia, New Zealand, and Türkiye. Under the agreement, Donga ST will be responsible for regulatory approval and sales in these regions and will also receive technology transfer for the production of the finished pharmaceutical product from SK BIOPHARMACEUTICALS.

A Donga ST official stated, “We hope Excofry will establish itself as a new treatment option for patients with epilepsy,” adding, “We will continue to contribute to helping patients reduce the difficulties in their daily lives caused by seizures and maintain stable treatment.”