SK Biopharmaceuticals Brings Cenobamate to Japan, Completing Northeast Asian Market Rollout

SK Biopharmaceuticals has expanded the commercial reach of its epilepsy treatment cenobamate with the launch of the drug in Japan, marking the company’s entry into three major Northeast Asian markets within the same year.

The company’s Japanese commercialization partner, Ono Pharmaceutical, began selling the treatment on November 13 under the brand name Exiscopri. Japan’s Ministry of Health, Labour and Welfare approved the drug in September, clearing the way for its introduction approximately two months later.

Cenobamate is indicated for adults with partial-onset seizures and is available in four tablet strengths: 12.5 mg, 50 mg, 100 mg and 200 mg. The Japanese launch follows the product’s introduction in China in March and South Korea earlier in November.

Japan represents a significant commercial opportunity for SK Biopharmaceuticals, with an estimated 1 million people living with epilepsy, making it the world’s second-largest market for the condition after the United States.

The company entered into a licensing agreement with Ono Pharmaceutical in October 2020, granting the Japanese drugmaker development and commercialization rights for cenobamate in the country. Under the arrangement, SK Biopharmaceuticals stands to receive royalty payments tied to Japanese product sales as commercialization progresses.

Cenobamate’s development in Asia included a Phase 3 clinical trial involving adult patients in South Korea, China and Japan whose partial-onset seizures remained inadequately controlled despite existing antiseizure medications. During the study’s six-week maintenance period, seizure freedom rates increased with dosage. Among patients receiving cenobamate, 12.4% in the 100 mg group, 30.1% in the 200 mg group and 52.4% in the 400 mg group experienced no seizures. The corresponding rate in the placebo group was 2.6%.

The latest market entry builds on the drug’s established international presence. Cenobamate has received approval for treating partial-onset seizures in adults in approximately 50 countries and regions, including the United States and Europe.

SK Biopharmaceuticals commercializes the treatment directly in the US through its subsidiary, SK Life Science, while relying on regional licensing and distribution partners in other international markets. Lee Dong-hoon, president of SK Biopharmaceuticals, says the launches in Japan, South Korea and China establish a foundation for broader commercialization across Northeast Asia. The company plans to build on its US commercial experience while adapting its market strategies to the needs and characteristics of individual regions.

With Japan now added to its commercial footprint in Asia, SK Biopharmaceuticals is looking to expand cenobamate’s contribution to its international business through regional partnerships and growing market access.

For more information, visit www.skbp.com.