Biohaven inks $795 million global epilepsy deal with SK Biopharmaceuticals

Under the agreement, Biohaven will receive $400 million in near-term cash, with $350 million payable at closing and $50 million expected in 2027. The deal includes an additional $150 million tied to future regulatory and development milestones, alongside tiered royalties on net sales. SK Biopharmaceuticals will also assume responsibility for ongoing program costs, including existing obligations to Knopp Biosciences totaling $245 million.

Opakalim, a selective Kv7.2/7.3 potassium channel activator, is currently in Phase 2/3 development for focal epilepsy. The drug is designed to minimize central nervous system side effects like sedation and dizziness, common complaints with existing antiseizure medications. Topline data from the RISE3 clinical trial is anticipated in the second half of 2026. For Biohaven, the partnership serves as a non-dilutive funding strategy that allows the company to focus capital on its broader pipeline, which spans protein degradation platforms and neuromuscular disease treatments, while leveraging SK Biopharmaceuticals’ established neurology sales force in the U.S.