In a randomized, placebo-controlled, time-to-event trial in idiopathic generalized epilepsy (IGE), the median time to the second day with a generalized tonic-clonic seizure was 141 days in the opakalim 75 mg once-daily treatment group vs. 47 days in the placebo group, representing a 3-fold prolongation. In an ongoing open-label extension (OLE) study in focal epilepsy, an updated data analysis shows 54% of patients with focal epilepsy on opakalim 75 mg once-daily achieved a ≥50% reduction in seizure frequency over any consecutive six months of open-label treatment compared to pre-randomization baseline. A six-month update of opakalim compassionate use treatment in a Kv7-activation dependent patient with KCNQ2-Developmental and Epileptic Encephalopathy (KCNQ2-DEE) confirms clinical stability and ongoing seizure control. Overnight EEG at 6-months demonstrated a 50% reduction in seizure counts relative to pre-opakalim baseline. Opakalim has been well-tolerated across all studies (1000+ subjects to date) with a low incidence of adverse events (AEs) comparing favorably with approved and investigational antiseizure medicines. In the IGE study, the opakalim group reported no cases of somnolence, dizziness, fatigue, or memory impairment; and in the focal epilepsy OLE study, rates of these central nervous system (CNS) AEs were less than or equal to 5% each. Opakalim's tolerability profile is markedly differentiated from that of other investigational Kv7 activators reporting double-digit rates of CNS AEs in OLE studies. On track to receive top-line results in 2H 2026 from the first of two pivotal Phase 2/3 randomized, double-blind, placebo-controlled studies in refractory focal epilepsy to support registration. NEW HAVEN, Conn. , May 26, 2026 /PRNewswire/ -- Biohaven Ltd. (NYSE: BHVN ), a global clinical-stage biopharmaceutical company focused on the discovery, development and commercialization of life-changing therapies to treat a broad range of rare and common diseases, today reported new data from its selective Kv7.2/7.3 channel activator program, currently in Phase 2/3 studies for the treatment of focal epilepsy, and will present additional updates at its annual R&D Day held in conjunction with the Yale Innovation Summit at the Yale School of Management in New Haven, Connecticut on May 27, 2026. Opakalim is distinguished from other investigational Kv7 activators by its selectivity for Kv7.2/7.3 and lack of GABA receptor activity. Opakalim offers potential for easy-to-use, once-daily, orally-administered treatment without the need for titration to control seizures, and without the burdensome central nervous system (CNS) side effects frequently reported with approved and investigational antiseizure medicines (ASMs). Continue Reading Figure 1: Opakalim 75 mg Once-Daily Prolongs Time-to-2nd Generalized Tonic-Clonic Seizure in Randomized, Double-blind, Placebo-Controlled, Time-to-Event Proof-of-Concept Trial in Idiopathic Generalized Epilepsy with Generalized Tonic-Clonic Seizures Figure 2: Updated Analysis From the Ongoing Open-Label Extension Study in Focal Epilepsy Shows 54% of Patients on Opakalim 75 mg Once-Daily Achieved a ≥50% Reduction in Seizure Frequency Compared to Pre-Randomization Baseline Figure 3: Updated Safety Data From the Ongoing Open-Label Extension Study in Focal Epilepsy Demonstrates Opakalim Is Well-Tolerated With a Markedly Lower Incidence of Adverse Events Compared to Approved and Investigational Antiseizure Medicines. The R&D Day presentation will showcase new and updated clinical data from: 1) a randomized, double-blind, placebo-controlled proof-of-concept study in idiopathic generalized epilepsy (IGE); 2) an ongoing focal epilepsy open-label extension (OLE) study; and 3) a six-month clinical update for a pediatric patient with KCNQ2 Developmental and Epileptic Encephalopathy (KCNQ2-DEE). Together, these emerging data reinforce opakalim's target engagement, differentiated profile and potential to address the unmet need for novel, effective, and well-tolerated ASMs. Jason Lerner, M.D., Medical Director, Research & Development and Epilepsy Development Lead at Biohaven, commented, "The opakalim data across IGE, focal epilepsy and KCNQ2-DEE are consistent and compelling. What stands out is not just that opakalim controls seizures — it's that it does so without the burdensome side effects that compromise quality of life and adherence for people with epilepsy. Dizziness, somnolence, fatigue, and memory impairment are reported in meaningful proportions of patients on existing and investigational ASMs. Opakalim's zero rates of somnolence, dizziness, fatigue, and memory impairment in our small IGE proof-of-concept study, and single-digit rates of CNS adverse events in our focal epilepsy program suggest that selective Kv7.2/7.3 activation is a fundamentally different and cleaner mechanism. I believe opakalim can offer people with epilepsy real seizure control without asking them to compromise their qua
