Transfer of Global Rights for Opakalim and the Kv7 Platform

Biohaven Ltd. (BHVN) has granted SK Biopharmaceuticals Co., Ltd. (326030) an exclusive global license for opakalim (BHV-7000), follow-on Kv7 activators, and the drug discovery platform. The deal is valued at up to USD 795M, with upfront cash payments totaling USD 400M (USD 350M at closing and USD 50M in 2027), which are non-repayable. The remaining USD 395M consists of USD 335M in development and regulatory milestones for opakalim and USD 60M in milestones for follow-on Kv7 programs. Of this, Biohaven will directly receive USD 150M in development and regulatory milestones, while SK Biopharmaceuticals will assume up to USD 245M in obligations related to Knopp Biosciences and follow-on programs, necessitating a clear distinction between the nominal total and Biohaven's cash inflow.

Acquisition of a Once-Daily Kv7 Therapeutic with Clinical Value

Opakalim, a once-daily oral antiepileptic drug without a brand name, selectively activates Kv7.2 and Kv7.3 potassium channels to modulate neuronal excitability. It is currently in Phase 2 RISE2 and Phase 3 RISE3 trials for the treatment of refractory focal seizures, with RISE3 (NCT06309966) expected to report top-line results in the second half of 2026. The drug is designed to eliminate the need for dose titration and reduce central nervous system side effects. However, its final efficacy and safety competitiveness will be determined by RISE3 data and FDA review. Biohaven will continue to conduct the trials, while SK Biopharmaceuticals will bear future development costs, maintaining clinical continuity while minimizing Biohaven's cash burn.

Proven XCOPRI Sales Force Combined with Late-Stage Pipeline

SK Biopharmaceuticals' marketed product XCOPRI (cenobamate) was approved by the FDA in November 2019 for the treatment of partial-onset seizures in adults. The FDA did not convene an advisory committee for XCOPRI due to clear efficacy results and an acceptable safety profile. SK Biopharmaceuticals plans to leverage its existing U.S. neurology sales force for opakalim to reduce the cost of building a dedicated commercial organization and aims to launch a second proprietary innovative drug in 2029. The transaction's industry significance lies in expanding its product portfolio to target the same patient population in the USD 11.7B (2025) and USD 12.3B (2026) global epilepsy treatment market.

XEN1101's Prior Phase 3 Results Raised the Bar

The direct competitor is azetukalner (XEN1101) from Xenon Pharmaceuticals Inc. (XENE), another Kv7-based Phase 3 candidate. In the X-TOLE2 trial, the 25mg dose group showed a 53.2% reduction in monthly seizure frequency, compared to 10.4% in the placebo group. Current standard-of-care therapies include XCOPRI, Keppra (levetiracetam), and Briviact (brivaracetam). The first Kv7 opener, Potiga (ezogabine/retigabine), was approved by the FDA on June 10, 2011, but was withdrawn in 2017 due to retinal abnormalities and skin discoloration. Therefore, the investment rationale for opakalim hinges on its ability to clinically demonstrate superior efficacy, tolerability, and dosing convenience compared to azetukalner. Biohaven will retain mid-teens to low-20s net sales royalties in the U.S. and mid-single-digit royalties outside the U.S., preserving upside potential for post-approval sales growth.