Xenon Pharmaceuticals Submits New Drug Application for Azetukalner in Focal Seizures

04:49 PM EDT, 09/17/2026 (MT Newswires) -- Xenon Pharmaceuticals (XENE) said late Thursday it submitted a new drug application for azetukalner in focal seizures to the US Food and Drug Administration. The submission is based on positive clinical data from two global, randomized, double-blind, placebo-controlled trials, including the phase 2b X-TOLE and phase 3 X-TOLE2 studies. All four doses of azetukalner across the studies demonstrated a statistically significant reduction from baseline in monthly seizure frequency versus placebo. The drug was generally well tolerated, with a consistent safety profile, according to the company. Ongoing phase 3 X-TOLE3 and X-ACKT studies are enrolling patients with focal seizures and primary generalized tonic-clonic seizures, respectively, to support expansion across seizure types and global regions. Xenon said it also paused enrollment of new patients in ongoing studies of major depressive disorder and bipolar depression after observing neuropsychiatric adverse events. The pause is expected to be temporary as the company evaluates potential dosing modifications.