Xenon Pharmaceuticals provides updates on neurology programs at AES 2022

Xenon Pharmaceuticals announced it will provide updates on its proprietary, neurology programs at the Annual Meeting of the American Epilepsy Society, AES 2022. In addition, the Company is presenting results from the open label extension, OLE, and sub-analyses of data from the XEN1101 Phase 2b X-TOLE clinical trial. Poster No. 2.235 "XEN1101, a Novel Potassium Channel Modulator: Interim Data From an Ongoing, Long-Term, Open-Label Extension of a Phase 2B Study in Adults With Focal Epilepsy" During the OLE, there was a sustained monthly reduction in seizure frequency from the double-blind period baseline, as of the analysis cutoff date of September 22, 2022. Seizure freedom for greater than or equal to 6-month and greater than or equal to12-month consecutive durations was achieved in 17.5% and 10.5% of patients, respectively. XEN1101 continues to be generally well-tolerated in the OLE with adverse events consistent with prior results and other anti-seizure medications. To date, two AEs of urinary retention occurred in the OLE possibly related to study drug; both patients continued in the study without requiring intervention. Poster No. 2.236 "Rapid Onset of Efficacy of XEN1101, a Novel Potassium Channel Opener, in Adults With Focal Epilepsy: Results From a Phase 2b Study" X-TOLE met the primary and key secondary efficacy endpoints with XEN1101 demonstrating a statistically significant, dose-dependent reduction from baseline in monthly focal onset seizure frequency compared to placebo. The rapid onset of efficacy for XEN1101 was associated with starting at an effective, therapeutic and well-tolerated dose. There was a statistically significant reduction in median FOS frequency within 1 week for all doses compared with placebo. The rapid onset of efficacy after 1 week and sustained efficacy of XEN1101, if confirmed in the Phase 3 clinical trials, suggests that XEN1101 may offer a compelling option for patients seeking adjunctive therapy. Poster No. 2.233 "The Impact of Disease Severity on Efficacy From a Phase 2b Study of XEN1101, a Novel Potassium Channel Opener, in Adults With Focal Epilepsy" X-TOLE met the primary and key secondary efficacy endpoints with XEN1101 demonstrating a statistically significant, dose-dependent reduction from baseline in monthly FOS frequency compared to placebo in a difficult-to-treat population. Based on the number of concomitant ASMs, baseline seizure frequency, and number of failed ASMs, the X-TOLE study enrolled more difficult-to-treat patients than other FOS studies. In the 25 mg dose group, XEN1101 reduced seizure frequency in sub-groups of patients with less than or equal to 8.5 seizures/month, and in patients that failed less than or equal to 6 ASMs or were on 1-2 concomitant ASMs by 70.6%, 58.0% and 60.9%, respectively, compared with placebo