SK Biopharm bets $800m on new epilepsy blockbuster

SK Biopharmaceuticals is staking nearly $800 million on rights to an epilepsy treatment from US biotech firm Biohaven, as it works to build a second blockbuster to stand alongside its existing epilepsy drug, the company said Wednesday.

The South Korean drugmaker struck an exclusive global licensing deal worth up to $795 million with Biohaven Bioscience Ireland for the epilepsy drug candidate opakalim (BHV-7000), along with other Kv7 potassium channel openers and Biohaven's Kv7 Discovery Platform.

"SK Biopharmaceuticals will enter a completely new phase of directly marketing multiple products in the US market," said CEO Lee Dong-hoon, framing the deal as a move to compete head-on with global big pharma and specialized central nervous system companies. "We want to play by a different set of rules, and we'll show what a true big biotech really looks like.”

Opakalim is an investigational treatment for partial-onset seizures that selectively activates Kv7 potassium channels to reduce excessive neuronal activity. Now being tested across two late-stage trials spanning Phase 2 and Phase 3, the compound is expected to yield topline results by year-end, with a second readout in 2028 and a targeted US launch as early as 2029.

SK Biopharmaceuticals will pay $400 million upfront, non-refundable, split between $350 million when the deal is closed and $50 million a year later. Development and regulatory milestones could add up to $395 million, plus royalties on net sales.

While clinical-stage candidates inherently carry risk, SK Biopharmaceuticals said due diligence by its epilepsy specialists, drawing on more than 30 years of experience across the drug's full lifecycle, pointed to a strong likelihood of success and clear differentiators, particularly favorable tolerability.

Opakalim's appeal centers on how well it fits SK Biopharmaceuticals' existing US infrastructure, where the company already markets its epilepsy drug Xcopri, with the two drugs' differing mechanisms for the same disease broadening treatment options and strengthening the company's long-term global standing.

"We can carry over the strength of our existing sales organization, controlling costs while generating revenue from two products," Lee said, pointing to the company's US-based sales force of more than 150 people and its network of major epilepsy centers and neurologists.

Lee cited the cash flow built by Xcopri as the backdrop for the large investment.

"Three years ago at a press conference, I said we would focus on making money first," he said. "The past three years were spent building, with conviction, a system that generates profit.”

SK Biopharmaceuticals posted cumulative operating profit of nearly 190 billion won ($140 million) in the first half of this year.