Xenon Pharmaceuticals Stock Up After Positive Topline Results from a Treatment of Focal Epilepsy Phase 2b Trial

Oct 4, 2021 By MarketDepth

Biotechnology Headlines Healthcare Investing What's Hot


Xenon Pharmaceuticals Inc. (NASDAQ: XENE) stock skyrocketed more than 75% on Monday after the biopharmaceutical Company announced positive topline results from the Phase 2b X-TOLE clinical trial, which evaluated the clinical efficacy, safety, and tolerability of XEN1101 – a differentiated Kv7 potassium channel modulator – administered as adjunctive treatment in adult patients with focal epilepsy. The trial met its primary efficacy endpoint with XEN1101 demonstrating a statistically significant and dose-dependent reduction from baseline in monthly (defined as 28 days) focal seizure frequency when compared to placebo (monotonic dose response; p<0.001). 

Anti-Seizure Medication

Jacqueline A. French, MD, Professor in the Department of Neurology at NYU Langone Health and Co-director of Epilepsy Clinical Trials at NYU Langone’s Comprehensive Epilepsy Center; Founder/Director of the Epilepsy Study Consortium; and Chair of the XEN1101 X-TOLE Steering Committee, stated, “Many patients today are living with the debilitating impacts of focal seizures, even while taking multiple anti-seizure medications, so there is a substantial need for new, efficacious and well-tolerated therapies. The X-TOLE results generated from this large, multicenter, controlled trial are truly exciting because they demonstrate impressive efficacy of XEN1101 for adult patients with focal epilepsy, including those with seizures that are deemed difficult to treat. In addition, physicians and patients could benefit from XEN1101’s other important attributes, such as once-a-day dosing in the evening with no titration. With its unique potassium channel mechanism-of-action, the strength of these topline data suggest XEN1101 could play an important role in treating focal epilepsy.”

Focus to Reduce Focal Seizures

The primary objective of the study was to assess the dose response trend of XEN1101 in reducing monthly focal seizure frequency, based on a ranked ANCOVA model. The median percent reduction in monthly focal seizure frequency was 52.8% in the XEN1101 25 mg group, 46.4% in the XEN1101 20 mg group, and 33.2% in the XEN1101 10 mg group compared to 18.2% in the placebo group. The monotonic dose response relationship between the XEN1101 active dose groups compared to placebo was statistically significant (p<0.001). These data demonstrated a highly statistically significant dose-response relationship for XEN1101 in the adjunctive treatment of focal seizures in adult patients with a history of difficult-to-treat seizures.

“On behalf of the entire Xenon team, I wish to extend our thanks to the patients, investigators, and site coordinators who participated in the X-TOLE study. We have generated strong evidence that supports the efficacy, safety and tolerability of XEN1101 and depicts a highly favorable product profile for XEN1101. Importantly, we saw statistically significant reductions of focal onset seizures compared to placebo across all dose groups, which suggests it is highly active in the central nervous system. With these compelling topline results, we are eager to work with the FDA to plan for an expedited development path moving forward.”

Dr. Christopher Kenney, Xenon’s Chief Medical Officer