SK BIOPHARMACEUTICALS announced on the 13th that its Japanese partner, Ono Pharmaceutical, has begun local sales of cenobamate. The product is marketed in Japan under the name “Ekiskopuri,” approximately two months after receiving new drug approval from Japan’s Ministry of Health, Labor and Welfare (MHLW) last September.
Senobamate went on sale in China in March of this year and was subsequently launched in South Korea and Japan this month.
According to the company, Japan is the world’s second-largest epilepsy market by a single country, following the United States, with an estimated 1 million patients. In Japan, the drug is available in 12.5 mg, 50 mg, 100 mg, and 200 mg tablets for patients with partial seizures.
Cenobamate underwent a Phase 3 clinical trial in Asia involving adult patients with partial seizures in South Korea, China, and Japan whose seizures were not adequately controlled by existing antiepileptic drugs. During the 6-week maintenance period, the proportion of patients who achieved complete seizure freedom was 12.4% in the 100 mg group, 30.1% in the 200 mg group, and 52.4% in the 400 mg group. The placebo group showed a rate of 2.6%. The most common adverse reactions occurring in more than 20% of patients in the cenobamate groups were dizziness and drowsiness.
In October 2020, SK BIOPHARMACEUTICALS licensed the rights to develop and commercialize cenobamate in Japan to Ono Pharmaceutical. With sales now underway in Japan, the company expects to generate royalty revenue tied to local sales.
Senobamate is currently approved in approximately 50 countries and regions, including the United States and Europe, as a treatment for partial-onset seizures in adults. In the United States, the company’s subsidiary, SK Life Sciences, handles sales directly, while in other major markets, the business is conducted through regional partners.
Lee Dong-hoon, President of SK BIOPHARMACEUTICALS, stated, “With the launch of Cenobamate in Japan, following its launches in South Korea and China, we have established a solid foundation for full-scale commercialization in key Northeast Asian markets.” He added, “We will expand the success of Cenobamate—built primarily in the U.S.—to the Asian market and drive sustained growth through strategies tailored to the specific characteristics of each region.”
