Abstract Details

Title The Impact of Disease Severity on Responder Rates in a Phase 2b Study of XEN1101, a Potent, Selective Potassium Channel Opener, in Adults with Focal Epilepsy (X-TOLE)

Topic Epilepsy/Clinical Neurophysiology (EEG)

Presentation(s) S19 - Epilepsy Clinical Trials and Long-term Studies (4:06 PM-4:18 PM)

Poster/Presentation
Number 004

Background In the DBP, XEN1101 showed a significant, dose-dependent, and rapid-onset reduction in FOS frequency in adults with a median of 13.5 seizures/month and 6 tried and stopped antiseizure medications (ASMs) at baseline. 50.5% were taking 3 concomitant ASMs. A post hoc analysis suggested that the efficacy of XEN1101, measured by the median percentage change (MPC) in monthly FOS frequency, may be most pronounced in patients with less-severe disease. We report the potential impact of baseline disease severity on the RR50, another widely used endpoint for evaluating ASMs.

Objective To report the impact of baseline disease severity on the percentage of patients achieving a ≥50% reduction in seizure frequency (RR50) in the double-blind period (DBP) of a phase 2b study (X-TOLE) of XEN1101 in adults with focal onset seizures (FOS).

Design/Methods Patients (n=325) received 25, 20, or 10 mg XEN1101 or placebo in a 2:1:1:2 ratio, QD with food, with no titration required. Post hoc analyses assessed the influence of baseline disease severity (seizure frequency, number of concomitant ASMs, and number of previously tried ASMs) on the RR50 in FOS frequency through the 8-week DBP.

Results RR50 was achieved by 14.9% of placebo (n=114) and 54.5% of XEN1101 25-mg (n=112) patients. With XEN1101 25-mg treatment, RR50 was achieved by 65.5% of patients with ≤8.5 seizures/month (n=29) and 50.6% with >8.5 seizures/month (n=83) at baseline, 64.2% of patients with ≤6 prior ASMs (n=67) and 40.0% with >6 ASMs (n=45), and 56.9% of patients with 1–2 concomitant ASMs (n=58) and 51.9% with 3 concomitant ASMs (n=54).

Conclusions Consistent with the significant MPC seizure reduction, 54.5% of patients in the 25-mg XEN1101 group achieved RR50. XEN1101 was relatively more effective in patients with indicators of less-severe disease. XEN1101 may be appropriate for patients with focal epilepsy across the spectrum of disease severity.

Authors/Disclosures
Roger J. Porter, MD, FAAN PRESENTER	Dr. Porter has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Xenon. Dr. Porter has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Neurocrine. Dr. Porter has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Longboard. Dr. Porter has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Engrail. Dr. Porter has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Axonis. Dr. Porter has received publishing royalties from a publication relating to health care.
Jacqueline French, MD, FAAN (NYU Comprehensive Epilepsy Ctr)	Dr. French has received personal compensation in the range of $50,000-$99,999 for serving as an officer or member of the Board of Directors for Epilepsy Foundation. The institution of Dr. French has received research support from Epilepsy Study Consortium/ Epilepsy Foundation (Funded by UCB). The institution of Dr. French has received research support from GW/One8 Foundation/FACES. The institution of Dr. French has received research support from NINDS. The institution of Dr. French has received research support from Xenon. The institution of Dr. French has received research support from Cerevel. The institution of Dr. French has received research support from FACES. The institution of Dr. French has received research support from UCB. The institution of Dr. French has received research support from Epilepsy Study Consortium. The institution of Dr. French has received research support from UCB. Dr. French has received personal compensation in the range of $100,000-$499,999 for serving as a Chief Medical/Innovation Officer with Epilepsy Foundation. Dr. French has a non-compensated relationship as a Consultant with Angelini that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a consultant with Alterity Therapeutics Limited that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a consultant with Bright minds Biosciences that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant with Cerecin Inc that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant with Cognizance Biomarkers that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant with Arvelle that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a consultant with Beacon biosignals that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant, Advisory Board with Biohaven Pharmaceuticals that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant with Bloom Science Inc that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant with BridgeBio Pharma Inc that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a consultant, scientific advisory board with Camp4 Therapeutics Corporation that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant, Scientific Advisory Board with Cerebral Therapeutics that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant with Cerevel that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a SAB with Coda Biotherapeutics that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant with Genentech Inc that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant with Crossject that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant with Eisai, that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant with Eliem Therapeutics that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant with Encoded Therapeutics that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant with iQure Pharma that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant, SAB with Engrail that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a SAB with Epihunter that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a SAB with Epiminder that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant with Epitel Inc that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant with Equilibre BioPharmaceuticals that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a consultant with Greenwich Biosciences that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant with Grin Therapeutics that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant with GW Pharma that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant with Janssen Pharmaceutica that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a consultant with Jazz Pharmaceuticals that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant with Knopp Biosciences that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant with Lipocine that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant with LivaNova that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant with Longboard Pharmaceuticals that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant, SAB with Lundbeck that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant, SAB with Marinus that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a consultant with Modulight Bio that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant with Leal therapeutics that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant with Neumirna Therapeutics that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant,SAB with Neurocrine that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant with Neuroelectrics USA Corporation that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant with Neuronetics Inc that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant with Ono Pharmaceutical Co that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant, SAB with Otsuka Pharmaceutical Development that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant, SAB with Ovid Therapeutics Inc that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant with Paladin Labs Inc that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant with Rapport Therapeutics that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant with Praxis that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant with PureTech LTY Inc that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a consultant with SK Life Sciences that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant with Stoke that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant with Supernus that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a consultant with Takeda that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant, SAB with UCB Inc that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant with Ventus Therapeutics that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a consulting, steering committee with Xenon that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a consultant with Korro Bio Inc that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant with NeuroPro Therapeutics that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Advisory board with Receptor that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Advisory board with Sage Therpeutics that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Advisory Board with Third Rock Ventures that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consultant with Vida Ventures Management that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consulting with Pfizer that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consulting with Agrithera, Inc that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a consulting with Autifony therapeutics, Unlimited that is relevant to AAN interests or activities. Dr. French has a non-compensated relationship as a Consulting with Baergic Bio that is relevant to AAN interests or activities.
Emilio Perucca	No disclosure on file
Martin Brodie	No disclosure on file
Cynthia L. Harden, MD (Xenon Pharmaceuticals Inc)	Dr. Harden has received personal compensation for serving as an employee of Xenon Pharmaceuticals Inc.. Dr. Harden has stock in Xenon Pharmaceuticals Inc.. Dr. Harden has received intellectual property interests from a discovery or technology relating to health care.
Constanza Luzon	Constanza Luzon has received personal compensation for serving as an employee of Xenon Pharmaceuticals Inc.. Constanza Luzon has stock in Xenon Pharmaceuticals.
Jenny Qian	No disclosure on file
Christopher Kenney	No disclosure on file
Gregory N. Beatch, PhD	Dr. Beatch has received personal compensation for serving as an employee of Xenon Pharmaceuticals Inc. Dr. Beatch has stock in Xenon Pharmaceuticals Inc. Dr. Beatch has received intellectual property interests from a discovery or technology relating to health care.