Xenon’s Azetukalner Cuts Seizure Frequency by 53.2%, Shares Soar 44%
Xenon Pharmaceuticals’ azetukalner achieved a 53.2% reduction in FOS frequency with 25mg and 34.5% with 15mg versus 10.4% placebo in the Phase III study. Shares jumped 44% from $41.94 to $60.56 following the trial readout, with analysts eyeing an NDA submission Q3 2026 for the potassium channel opener.
1. Phase III X-TOLE2 Trial Results
Azetukalner met its primary endpoint in the global Phase III X-TOLE2 study, reducing monthly focal onset seizure frequency by 53.2% at a 25mg dose and 34.5% at 15mg compared with a 10.4% reduction for placebo at week 12.
2. Share Price Reaction
Following the positive readout, Xenon’s share price jumped 44% from $41.94 at close on March 6 to $60.56 at open on March 9, reflecting strong investor confidence in the drug’s market potential.
3. Safety Profile and Mechanism of Action
The drug’s safety and tolerability remained consistent with prior studies, with dizziness, somnolence and headache as the most common adverse events; azetukalner acts by opening neuronal Kv7.2/Kv7.3 potassium channels to reduce seizure excitability.
4. Regulatory Pathway
Xenon plans to submit a New Drug Application in Q3 2026 for focal onset seizures, potentially making azetukalner the first potassium channel opener approved for this indication.