Xenon Pharmaceuticals (XENE.US) surged more than 42% at Monday's market open, reaching $59.59 per share. The significant move follows the company's announcement on March 9 that its Phase 3 X-TOLE2 study for Azetukalner in treating focal epilepsy successfully met its primary endpoint. Results showed a 53.2% median reduction in seizure frequency for the 25mg dose group, compared to a 10.4% reduction in the placebo group, with a p-value of 0.000000000006. The company confirmed that Azetukalner's safety profile was consistent with earlier studies and demonstrated good tolerability. Xenon Pharmaceuticals also announced plans to submit a New Drug Application for Azetukalner to the U.S. FDA in the third quarter of 2026. In a separate development, William Blair analyst Myles Minter maintained a Buy rating on Xenon Pharmaceuticals.