Exhibit 99.1 Xenon Reports Second Quarter 2025 Financial Results & Business Update VANCOUVER, BC and BOSTON, MA, August 11, 2025 – Xenon Pharmaceuticals Inc. (Nasdaq: XENE), a neuroscience-focused biopharmaceutical company dedicated to drug discovery, clinical development, and commercialization of life-changing therapeutics for patients in need, today reported financial results for the second quarter ended June 30, 2025, and provided a business update. "The completion of patient recruitment for our Phase 3 ...