Xenon to Showcase Long-Term 36-Month Azetukalner Data at AAN 2025

• Three epilepsy posters to be presented in scientific sessions at the American Academy of Neurology meeting
• Long-term 36-month data from the ongoing X-TOLE OLE study of azetukalner in focal onset seizures (FOS)
• Exploratory analysis of efficacy of azetukalner in FOS seizure sub-types
• Patient survey findings on mental health and comorbidity burdens of FOS

VANCOUVER, British Columbia and BOSTON, April 04, 2025 (GLOBE NEWSWIRE) -- Xenon Pharmaceuticals Inc. (Nasdaq: XENE), a neuroscience-focused biopharmaceutical company dedicated to discovering, developing, and delivering life-changing therapeutics for patients in need, today announced multiple presentations at the upcoming American Academy of Neurology Annual Meeting (AAN 2025), taking place April 5-9, 2025 in San Diego, CA. Three posters will be presented, including long-term data from the ongoing X-TOLE open-label extension (OLE) study of azetukalner in patients with focal onset seizures (FOS). The Company will also present an exploratory efficacy analysis of FOS seizure subtypes from the X-TOLE study, as well as patient survey findings about the mental health and comorbidity burdens of FOS.

“Building upon more than 700+ patient-years of data to date, we are excited to share our 36-month azetukalner data from our ongoing X-TOLE open-label extension study in FOS showing sustained monthly reduction in seizure frequency, impressive seizure freedom rates, and a consistent AE safety profile suggesting long-term efficacy and tolerability of azetukalner,” stated Dr. Christopher Kenney, Chief Medical Officer of Xenon. “We are also presenting an exploratory analysis from our X‑TOLE study showing reduced seizure frequency rate across four focal seizure subtypes. These promising data sets support our conviction that azetukalner may offer hope for people who continue to seek new efficacious and well-tolerated therapies to address the debilitating impacts of uncontrolled seizures.”

• Poster 9‑001: Long-term Safety and Efficacy of Azetukalner, a Novel, Potent Kv7 Potassium Channel Opener in Adults With Focal Epilepsy: Update From the Ongoing 7-year Open-Label Extension of X-TOLE
  Presenter: Jacqueline A. French, MD, New York University Grossman School of Medicine and NYU Langone Health
  Session: P8: Epilepsy/Clinical Neurophysiology (EEG): Anti-seizure Medications: Clinical Trials
  Date/Time: April 8 from 8:00 am – 9:00 am PT

• Poster 9-012: Efficacy of Azetukalner in Focal Onset Seizure (FOS) Subtypes: Results From the Double‑Blind, Placebo‑Controlled X‑TOLE Study
  Presenter: Constanza Luzon Rosenblut, MD, Xenon Pharmaceuticals
  Session: P8: Epilepsy/Clinical Neurophysiology (EEG): Anti-seizure Medications: Clinical Trials
  Date/Time: April 8 from 8:00 am – 9:00 am PT

• Poster 9‑001: Is the Mental Health Burden of Epilepsy Under-Recognized in Patients Reporting Focal Onset Seizures? A Patient-Reported Outcomes Study
  Presenter: Joanne M. Wagner, PhD, Xenon Pharmaceuticals
  Session: P6: Epilepsy/Clinical Neurophysiology (EEG): Health Care Utilization and Disparities in Epilepsy
  Date/Time: April 7 from 11:45 am – 12:45 pm PT

Exhibit Hall

Xenon is hosting booth #1110 in the Exhibit Hall, which is scheduled to open at 11:30 am PT on Saturday, April 6 and close on Wednesday, April 9 at 4:00 pm PT.

About Xenon Pharmaceuticals Inc.
Xenon Pharmaceuticals (Nasdaq: XENE) is a neuroscience-focused biopharmaceutical company dedicated to discovering, developing, and delivering life-changing therapeutics. We are advancing an ion channel product portfolio to address areas of high unmet medical need, including epilepsy and depression. Azetukalner, a novel, highly potent, selective Kv7 potassium channel opener, represents the most advanced, clinically validated potassium channel modulator in late-stage clinical development for multiple indications. For more information, please visit www.xenon-pharma.com.

Safe Harbor Statement
This press release contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended, and the Private Securities Litigation Reform Act of 1995 and Canadian securities laws. These forward-looking statements are not based on historical fact, and include statements regarding the timing of and potential results from clinical trials; the potential efficacy, safety profile, future development plans in current and anticipated indications, addressable market, regulatory success and commercial potential of our and our partners’ product candidates; the efficacy of our clinical trial designs; our ability to successfully develop and achieve milestones in our azetukalner and other pipeline and development programs; and our ability to successfully develop and obtain regulatory approval of azetukalner and our other product candidates. These forward-looking statements are based on current assumptions that involve risks, uncertainties and other factors that may cause the actual results, events, or developments to be materially different from those expressed or implied by such forward-looking statements. These risks and uncertainties, many of which are beyond our control, include, but are not limited to: clinical trials may not demonstrate safety and efficacy of any of our or our collaborators’ product candidates; promising results from pre-clinical development activities or early clinical trial results may not be replicated in later clinical trials; our assumptions regarding our planned expenditures and sufficiency of our cash to fund operations may be incorrect; our ongoing discovery and pre-clinical efforts may not yield additional product candidates; any of our or our collaborators’ product candidates, including azetukalner, may fail in development, may not receive required regulatory approvals, or may be delayed to a point where they are not commercially viable; we may not achieve additional milestones in our proprietary or partnered programs; regulatory agencies may impose additional requirements or delay the initiation of clinical trials; the impact of market, industry, and regulatory conditions on clinical trial enrollment; the impact of competition; the impact of expanded product development and clinical activities on operating expenses; the impact of new or changing laws and regulations; as well as the other risks identified in our filings with the U.S. Securities and Exchange Commission and the securities commissions in British Columbia, Alberta, and Ontario. These forward-looking statements speak only as of the date hereof and we assume no obligation to update these forward-looking statements, and readers are cautioned not to place undue reliance on such forward-looking statements.

“Xenon” and the Xenon logo are registered trademarks or trademarks of Xenon Pharmaceuticals Inc. in various jurisdictions. All other trademarks belong to their respective owner.

Contacts:
For Investors:
Chad Fugere
Vice President, Investor Relations
(857) 675-7275
investors@xenon-pharma.com

For Media:
Colleen Alabiso
Senior Vice President, Corporate Affairs
(617) 671-9238
media@xenon-pharma.com