Launch of Potassium Channel Modulator Phase 3 Program with Initiation of X-TOLE2 and X-TOLE3 Clinical Trials in Patients with Focal Onset Seizures

The phase 3 program for differentiated Kv7 potassium channel modulator (XEN1101; Xenon Pharmaceuticals, Burnaby, British Columbia) as treatment for adults with focal epilepsy has launched. The phase 3 development program includes 2 identical phase 3 clinical trials: X-TOLE2 and X-TOLE3, which will be run in parallel. The median percent change in monthly seizure frequency from baseline through the double-blind period of potassium channel modulator compared with placebo will be measured as a primary efficacy endpoint. The trials are multicenter, randomized, double-blind, placebo-controlled, and designed to evaluate the clinical efficacy, safety, and tolerability of XEN1101 administered as adjunctive treatment in approximately 360 participants with focal onset seizures. 

There will also be a phase 3 clinical trial, X-ACKT, to support potential regulatory submissions in an additional epilepsy indication of primary generalized tonic clonic seizures (PGTCS). This study will evaluate the clinical efficacy, safety, and tolerability of the potassium channel modulator administered as adjunctive treatment in approximately 160 participants with PGTCS. The primary efficacy endpoint is the MPC in monthly seizure frequency from baseline through the double-blind period compared to placebo. 

Ian Mortimer, Xenon’s president and chief executive officer, stated, “We are thrilled to announce the launch of our XEN1101 phase 3 program with the initiation of our X-TOLE2 clinical trial. We have ambitious clinical development plans for XEN1101, including our X-TOLE2 and X-TOLE3 clinical trials in focal onset seizures, as well as our phase 3 X-ACKT clinical trial in primary generalized tonic clonic seizures. We continue to hear from key opinion leaders and prescribing physicians that novel mechanisms are needed to provide new therapeutic options that are clearly differentiated from the anti-seizure medications currently available. Backed by a strong scientific rationale and compelling phase 2b clinical data, we are focused on advancing XEN1101 through its late-stage clinical development towards commercialization, with the goal of providing new therapies for epilepsy patients in need.”