Xenon Pharmaceuticals filed a New Drug Application with the FDA for azetukalner to treat focal seizures, a step toward what could become its first marketed therapy, while suspending new enrollment in major depressive disorder and bipolar depression studies after identifying neuropsychiatric adverse reactions. Xenon said the events included confusion, excessive drowsiness, coordination problems and isolated psychotic episodes. It described the pause as temporary and precautionary, with epilepsy studies unaffected, and is evaluating lower doses or gradual dose escalation before any recruitment restart. Shares fell sharply in Friday premarket trading, with reports citing declines of 25% to $42.84 and 27.6% to $41.51. Deutsche Bank cut its rating to Hold and lowered its target to $46 from $90, while Needham retained a Buy rating and reduced its target to $60 from $78. Wells Fargo maintained an Overweight rating, saying the psychiatric-program interruption did not affect the focal-onset seizure program. X-NOVA2, Xenon's Phase 3 major depressive disorder trial, had enrolled 80% of its planned 450 participants before the halt, with topline data anticipated in the first quarter of 2027.