Xenon Pharmaceuticals to Present Long-Term Azetukalner Data at AES 2025, Highlighting Extended Seizure Freedom
Key Insights
Xenon Pharmaceuticals will present seven posters at AES 2025, including new long-term data from the ongoing X-TOLE open-label extension study of azetukalner in patients with focal onset seizures (search).
The presentations will feature ≥48-month interim analysis data characterizing patterns of seizure freedom epochs with extended use of azetukalner, which could inform future clinical practice.
Additional data will highlight the impact of depression (search) on epilepsy (search) patients and new pre-clinical findings from the company's early-stage NaV1.1 (search) program in Dravet syndrome (search).
Xenon Pharmaceuticals Inc. (Nasdaq: XENE) announced it will present seven posters at the American Epilepsy (search) Society Annual Meeting (AES 2025), taking place December 5-9, 2025 at the Georgia World Congress Center in Atlanta, Georgia. The presentations include new long-term data from the ongoing X-TOLE open-label extension study of azetukalner in patients with focal onset seizures (search) (FOS), along with data characterizing patterns of seizure freedom epochs with extended use of the investigational drug.
Long-Term Efficacy and Safety Data
Two key presentations will focus on azetukalner's long-term performance in epilepsy (search) patients. The first poster will characterize long-term seizure freedom in the ongoing open-label extension of X-TOLE, with potential implications for future clinical practice. The second presentation will provide a ≥48-month interim analysis of the ongoing 7-year X-TOLE open-label extension study, examining the long-term safety and efficacy of azetukalner, described as a novel, potent KV7 potassium channel (search) opener, in adults with focal epilepsy.
According to the company, the new X-TOLE OLE data supports "the ability to attain and regain extended periods of seizure freedom with long-term use of azetukalner."
Real-World Epilepsy Studies
Four additional posters will address real-world aspects of epilepsy (search) management, including the impact of depression (search) on patients with epilepsy and the burden of anti-seizure medication titration. These studies examine depression symptom experience among patients with focal seizures, the impact of depression on outcomes and treatment patterns in newly diagnosed epilepsy patients, and the economic and humanistic burden among patients experiencing moderate to severe depression symptoms.
Early-Stage Pipeline Development
Xenon will also present pre-clinical data from its early-stage NaV1.1 (search) program in Dravet syndrome (search). The poster titled "Selective Potentiation of NaV1.1 Channels in Dravet Mice Suppresses Spontaneous Seizures, Prevents SUDEP and Increases Long Term Potentiation" demonstrates the company's broader neuroscience pipeline beyond azetukalner.
Expert Panel Discussion
In partnership with the Epilepsy Foundation of America (EFA), Xenon is hosting a symposium entitled "Exploring Depression (search) and Anxiety in Epilepsy (search): A Practical Dialogue with Patients and Providers" on Saturday, December 6, 2025. The panel will feature Dr. Jacqueline A. French, epileptologist and neurologist with the NYU Langone Comprehensive Epilepsy Center (search), Dr. Andres M. Kanner, Professor of Clinical Neurology and Director of the Comprehensive Epilepsy Center at the University of Miami, Miller School of Medicine, and Dr. Heidi Marie Munger Clary, Associate Professor of Neurology at Wake Forest University School of Medicine (search).
About Azetukalner
Azetukalner is Xenon's lead molecule, currently in Phase 3 clinical trials for the treatment of epilepsy (search), major depressive disorder (search) (MDD) and bipolar depression (search) (BPD). The drug is characterized as a novel, potent, selective KV7 potassium channel (search) opener. Xenon is also advancing an early-stage portfolio of multiple promising potassium and sodium channel modulators, including KV7 and NaV1.7 programs in Phase 1 development for the potential treatment of pain.
The company will also host a Scientific Exhibit on Sunday, December 7, 2025, providing an overview of its clinical- and pre-clinical-stage research programs. All posters will be available after the live presentations, with detailed scheduling information provided for each session at the conference.