SK Biopharm to acquire Biohaven epilepsy drug for up to $795 million

SK Biopharm will acquire a U.S. biotech Biohaven’s epilepsy drug candidate for up to $795 million (approximately 1.097 trillion won).

SK Biopharm said on the 26th (local time) that it had signed an agreement to secure worldwide rights to Biohaven’s potassium ion (Kv7) channel activator opicalim (BHV-7000) and its Kv7 platform.

Under the agreement, SK Biopharm will pay $350 million upfront and an additional $50 million next year. It will then pay up to $150 million in development and regulatory milestones, as well as separate royalties if opicalim is launched.

In addition, SK Biopharm agreed to assume some of Biohaven’s milestone obligations to Knopp Biosciences, the original developer of opicalim. The amount totals $245 million, bringing the maximum total SK Biopharm could pay in connection with the agreement to $795 million.

Opicalim is an oral treatment taken once daily, and Biohaven is conducting a phase 2/3 trial in patients with focal-onset (partial-onset) epilepsy. Topline results are expected later this year.

SK Biopharm entered the epilepsy field after receiving U.S. Food and Drug Administration (FDA) approval for the focal-onset seizure treatment Xcopri in 2019. Through its U.S. subsidiary SK Life Science, it aims to launch opicalim in the United States as early as 2029.

SK Biopharm CEO Dong-hoon Lee said, "Our experience taking Xcopri from clinical development through global launch has given us a deep understanding of what is needed to deliver differentiated central nervous system (CNS) medicines to patients."

Biohaven CEO Vlad Coric said, "SK Biopharm’s proven epilepsy development and commercialization capabilities will provide the fastest and strongest path to patients if opicalim is approved."

Meanwhile, opicalim will compete with rival Xenon Pharmaceuticals’ oral Kv7 activator azetukalner. Azetukalner passed a phase 3 seizure trial earlier this year and is currently being studied in a late-stage trial for generalized epilepsy.

At its research and development (R&D) day in May, Biohaven disclosed results from an analysis of an open-label extension study in patients with progressive focal-onset epilepsy. The analysis found that 54% of participants who took opicalim 75 mg once daily experienced a reduction of at least 50% in seizure frequency during the 6-month treatment period.