Xenon Pharmaceuticals disclosed a voluntary pause in enrollment for its azetukalner trials in major depressive disorder and bipolar disorder after neuropsychiatric adverse events emerged. The company said patients already enrolled will continue, while recruitment stops to evaluate safety signals observed in the broader population. The decision comes alongside ongoing regulatory activity: Xenon noted the same compound (a KV7 potassium channel opener) is under FDA review for focal onset seizures. Market impact was immediate in reporting, with shares sliding sharply after the depression enrollment pause. Xenon characterized the adverse events as consistent with known safety profile and said they were mild to moderate, short in duration, and reversible, while indicating it will consider dosing modifications and anticipates data from the ongoing trials in early 2027.