Xenon stock plunges as B.C. drug developer pauses enrolment in depression study

Xenon stock plunges as B.C. drug developer pauses enrolment in depression study SEAN SILCOFF TECHNOLOGY REPORTER PUBLISHED YESTERDAY Open this photo in gallery: Ian Mortimer, CEO of Xenon, at the company's lab in Burnaby, B.C, in 2023. He said side effects triggered by azetukalner in a new trial to treat depression were mostly mild or moderate, and 'consistent with the known profile' of the drug. TIJANA MARTIN/THE GLOBE AND MAIL COMMENTS SHARE SAVE FOR LATER Listen to this article Learn more about audio Log in or create a free account to listen to this article. Xenon Pharmaceuticals Inc. XENE-Q -30.69% decrease stock sold off sharply Friday after the B.C. drug developer said it was temporarily halting enrolment in a late-stage human trial to see if its lead drug candidate, which has proven effective in reducing seizures for people with epilepsy, would also work as an antidepressant. The Nasdaq-listed stock was down about 30 per cent in early afternoon trading, changing hands for US$39.91 a share after closing Thursday at US$57.35. Xenon, one of Canada’s most valuable public biotechnology development companies by market capitalization, said late Thursday it was pausing enrolment in the efficacy trial studying the drug’s effects on major depressive disorder after the drug was found to trigger a small number of adverse events in some patients. Those side effects were mostly mild or moderate, chief executive officer Ian Mortimer said on a conference call with analysts Thursday, and “consistent with the known profile” of the drug. Chief medical officer Chris Kenney said a “small percentage of patients” experienced adverse effects in the depression trial, including confusion, aphasia and ataxia. One patient suffered from psychosis. Dr. Kenney said those side effects did not last long. The setback overshadowed news Thursday that Xenon had submitted a new drug application (NDA) to the U.S. Food and Drug Administration for approval to take azetukalner to market to treat the most common type of epileptic seizures. Xenon signalled in March it would proceed with the application this year after reporting strong clinical data showing a meaningful reduction in seizures among people who took the drug. “Our NDA submission is a significant milestone for Xenon as we continue to work toward the potential approval and launch of our first product,” Mr. Mortimer said. If approved it would be the 15th therapy developed in B.C.’s teeming biotechnology sector to win…