K-biotech epilepsy drug that swept US market set to arrive in South Korea

Xcopri, the epilepsy drug developed by a South Korean biotech company that has taken the US market by storm, is on the verge of finally reaching domestic patients. After a roughly six-year delay following its US approval, the long wait for Korean patients — many of whom resorted to costly reimports — appears to be nearing an end.

The Health Insurance Review and Assessment Service convened its seventh Drug Benefit Evaluation Committee meeting on July 2 and voted to recognize Xcopri as appropriate for national health insurance coverage. The drug — developed by SK Biopharm and licensed to Dong-a ST for domestic distribution — was approved for reimbursement as an adjunctive therapy for partial-onset seizures in patients whose symptoms are not adequately controlled by existing antiepileptic drugs.

Cenobamate, the active ingredient in Xcopri, has posted explosive growth in the United States since receiving FDA approval in 2019. In the first quarter of this year, it recorded quarterly sales of 197.7 billion won ($127 million) in the US market alone — a 48.4 percent increase from the same period a year earlier — cementing its dominant market position. Prescription figures have also climbed sharply: as of March, monthly total prescriptions approached 47,000, while new patient prescriptions surpassed 2,000 for the first time.

The path to bringing the domestically developed drug home has been a long one. Dong-a ST took the first step in January 2024 by signing a license-in agreement with SK Biopharm for domestic rights to cenobamate. The company then obtained domestic product approval from the Ministry of Food and Drug Safety in November 2025 as the country's 41st new drug, clearing the way for a full domestic launch — but the drug still had to clear the reimbursement listing process.

In the meantime, Korean epilepsy patients faced a paradoxical situation: to access a drug developed in their own country, they had to pay out of pocket to import the European version, Ontozry, through the Korea Orphan and Essential Drug Center. Supply of Ontozry through that channel surged 4.1-fold over the past year alone, with patients bearing the full cost themselves — roughly 250,000 won per month, or about 3 million won per year, including overseas shipping and concessions — and waiting six to eight weeks from application to delivery.

Xcopri's global popularity stems from its strong clinical efficacy. Epilepsy is a condition in which abnormal electrical activity in brain neurons triggers repeated seizures, requiring continuous medication management. Cenobamate works through a dual mechanism of action that controls seizures in the brain. In multinational clinical trials, it demonstrated a significant reduction in seizure frequency and proved a complete seizure-freedom rate — meaning some patients experienced no seizures at all during the treatment period — earning it wide recognition in the global market.

With the drug benefit committee's approval now secured, Xcopri is expected to enter the domestic market as early as next year, pending price negotiations with the National Health Insurance Service and a final vote by the Health Insurance Policy Deliberation Committee. Its entry into South Korea's national health insurance system is expected to ease the financial burden on domestic patients and improve their access to treatment.