Opakalim

iStock, BeritK The enrollment pause comes after BHV-7000 failed to show efficacy in a midstage depression trial late last year. The news is another regulatory hit for Biohaven after the FDA declined to approve its spinocerebellar ataxia treatment in November 2025. Biohaven stock fell more than 13% in premarket trading Thursday as the FDA slapped a partial clinical hold on its Kv7 potassium channel agonist in focal epilepsy. This latest development comes days after SK Biopharmaceuticals snagged a worldwide license to the Kv7 platform, including the epilepsy candidate. It’s also the second regulatory blow to Biohaven in a year. Last November, the FDA turned away the biotech’s spinocerebellar ataxia treatment troriluzole, causing the company to slash its R&D budget by 60%. Biohaven’s shares dropped by nearly 45% at the time and have yet to fully recover. The partial hold on BHV-7000, which is also known as opakalim, pertains to the enrollment of new patients in two late-stage focal epilepsy studies. It was placed so the FDA could assess potential risk to humans from a metabolite identified during rodent testing, according to a Thursday SEC filing from Biohaven. The agency is requesting that Biohaven complete additional nonclinical research for more information. Dosing will continue for all patients already randomized in the two pivotal trials— RISE 2 and RISE 3 —which together comprise more than 600 participants. Enrollment in RISE 3 was completed in June, Biohaven said in the same filing, and a topline data readout remains on track for the second half of this year. RISE 2, however, had not yet completed recruitment. The enrollment pause “is likely to delay the readout of this trial, which will also likely will need to read out positively for regulatory approval,” RBC Capital Markets said in a note to investors Thursday morning. RISE 2 was previously expected to have a primary completion date in December this year. “The significance of the nonclinical metabolite findings to humans is uncertain,” Biohaven said in the filing. “The findings may be specific to rodents and not relevant to human safety, and the additional nonclinical studies underway are intended to address that question. BHV-7000 has generally been safe and well-tolerated in clinical studies with over 1,200 participants dosed to date.” RBC analysts also pointed to this comprehensive safety profile, writing: “If the partial clinical hold is not lifted or nonclinical data is not able to definitively demonstrate that the metabolite does not pose any risk to humans, we believe that BHVN may still be able to potentially rely upon the wealth of human data that they have to reassure regulators that ‘7000 may not pose greater risk to humans.” This partial pause is not the first trouble Biohaven has encountered with the Kv7 asset. In December 2025, BHV-7000 failed to improve symptoms in patients with major depressive disorder after six weeks as compared to placebo during a Phase 2 proof-of-concept study. Depression Biohaven Notches Another Psychiatric Failure Months After Key FDA Rejection The major depressive disorder failure for BHV-7000 is the drug’s second, after Biohaven’s spinocerebellar ataxia treatment troriluzole was rejected by the FDA in November 2025. January 2, 2026 · 1 min read · Annalee Armstrong Read more BHV-7000 is the lead asset from Biohaven’s Kv7 platform. The asset is a “potent, selective activator of Kv7.2/7.3 potassium channels,” a clinically validated target to regulate the hyperexcitable state in epilepsy, according to the company’s website . “Increasing evidence also suggests the potential for Kv7.2/7.3 activators to treat neuropsychiatric and pain disorders.” On Aug. 26, Biohaven Bioscience Ireland Limited signed a worldwide licensing agreement worth up to $795 million with SK Biopharmaceuticals for Biohaven’s Kv7 ion channel platform, including BHV-7000 as well as other Kv7 compounds and products covered by the agreement. “All clinical and nonclinical data, including those related to the metabolite characterization submitted to global regulatory authorities, was fully disclosed to SKBP prior to the signing of the License Agreement,” according to the SEC filing.

SK Biopharmaceuticals has strengthened its epilepsy offering by paying $350 million upfront to help speed Biohaven’s Kv7 ion channel activator on its way to market. Biohaven is currently evaluating the daily oral therapy, called opakalim or BHV-7000, in a phase 2/3 study of patients with focal epilepsy. A topline readout is expected later this year. Rather than wait for the results, SK has agreed to hand over the upfront cash—along with another $50 million next year—for the worldwide license to both opakalim and Biohaven’s Kv7 platform. Beyond those near-term paydays, Biohaven will also be in line for up to $150 million in development and regulatory milestone payments, as well as a slice of the royalties should opakalim make it to market. Another element of the deal will see SK take on responsibility for certain milestone responsibilities that Biohaven owes the drug's original developer Knopp Biosciences in relation to the Kv7 platform. These obligations reach $245 million and mean that the total amount SK could eventually pay out in relation to this morning’s deal could reach $795 million. SK became an epilepsy player in its own right when it scored FDA approval for Xcopri in 2019 as a treatment for treat partial-onset seizures. The South Korean biopharma is hoping to launch opakalim in the U.S. as soon as 2029 via its U.S. subsidiary SK Life Science. SK’s CEO Donghoon Lee said the company’s experience with taking Xcopri from clinical development through to global rollout “has given us a deep understanding of what it takes to bring a differentiated CNS medicine to patients.” “We see opakalim as a highly complementary addition to our epilepsy portfolio, with a mechanism and tolerability profile that could extend our ability to serve patients who may benefit from additional treatment options,” Lee added. “We look forward to a close, collaborative partnership with the Biohaven team through NDA submission and beyond.” Biohaven CEO Vlad Coric, M.D., said that SK's “established epilepsy development and commercialization expertise gives opakalim, if approved, its fastest and strongest path to patients worldwide.” “Rather than stand up a commercial organization of our own for opakalim, we structured a partnership with a leading strategic partner in epilepsy to drive long-term revenue potential of this novel mechanism,” Coric explained. “This partnership also brings $400 million in near-term, non-dilutive capital to Biohaven while preserving substantial long-term upside for our shareholders.” Opakalim will be in a tough race with Xenon Pharmaceuticals’ own oral Kv7 ion channel activator azetukalner, which has already aced a phase 3 seizure trial earlier this year and is undergoing a late-stage study for generalized epilepsy. For its part, Biohaven has been touting opakalim’s ability to selectively activate the Kv7.2/7.3 heteromeric channels, while lacking GABA receptor activity, as “distinguishing it from other investigational Kv7 activators.” In this morning’s release, Coric explained that opakalim is designed to “deliver meaningful efficacy without the burdensome central nervous system side effects, including sedation and dizziness, associated with so many antiseizure medicines.” The Connecticut-based biopharma used its R&D Day in May to unveil an analysis from an open-label extension study of patients with ongoing focal epilepsy that showed that 54% of participants who received 75 mg of opakalim once daily achieved a 50% or greater reduction in seizure frequency over six months of treatment. The company also claimed at the time that the candidate had demonstrated “markedly lower incidence of nervous system adverse events” than other approved or investigational antiseizure medicines. The content above comes from the network. if any infringement, please contact us to modify.