XENE Files NDA for Epilepsy Drug, Falls on Depression Studies' Setback

Xenon Pharmaceuticals filed a New Drug Application with the FDA for azetukalner to treat focal onset seizures, backed by positive phase IIb and phase III epilepsy data demonstrating significant seizure reductions. The stock fell 27% in premarket trading after the company paused enrollment in its depression program due to neuropsychiatric adverse events observed in trial participants.

The X-NOVA2 depression study is 80% enrolled, with top-line data still expected in Q1 2027. The company submitted the epilepsy NDA based on completed studies showing the drug's efficacy in reducing seizures, though specific reduction percentages were not disclosed. The neuropsychiatric safety signals emerged during the depression trial enrollment, prompting the temporary pause.

XENE now faces a bifurcated outlook: regulatory review for its lead epilepsy indication proceeding while its depression program undergoes safety review.