Xenon Pharmaceuticals (XENE) Stifel 2024 Healthcare Conference summary

Strategic overview and clinical milestones

• 2025 is positioned as a pivotal year, with major phase 3 data readouts in epilepsy and significant progress in depression trials.

• Three parallel phase 3 trials for azetukalner in epilepsy are ongoing, including two for focal onset seizures and one for primary generalized tonic-clonic seizures.

• The first phase 3 trial in major depressive disorder (MDD) will start by year-end, with two additional studies to follow in a staggered manner.

• Long-term efficacy and safety data for azetukalner in epilepsy will be presented at the American Epilepsy Society meeting, with over 600 patient-years of exposure.

• The company is preparing for a potential NDA filing and commercial launch of azetukalner for epilepsy in the U.S. following the X-TOLE2 readout in the second half of 2025.

Clinical trial design and risk mitigation

• Phase 3 epilepsy studies closely mirror the robust phase 2b design, with increased sample size and extended double-blind period from 8 to 12 weeks.

• Placebo rates are managed through geographic and site selection, leveraging experienced sites and electronic diaries for data capture.

• The phase 3 program in MDD increases patient severity criteria and reduces the number of drug arms to lower placebo rates and improve statistical power.

• Investigator-sponsored MDD study focuses on mechanistic endpoints (fMRI) rather than statistical significance, supplementing the larger phase 3 program.

Pipeline development and future directions

• Pipeline maturity is accelerating, with multiple INDs expected in 2025 and 2026, including Kv7, NaV1.1, and NaV1.7 programs.

• Kv7 follow-on molecules aim for chemical and therapeutic diversity, potentially expanding beyond epilepsy and psychiatry.

• NaV1.1 program targets Dravet syndrome, showing promising preclinical efficacy and survival data, with potential for broader application.

• NaV1.7 program is advancing toward IND submission, with differentiated chemistry and preclinical safety data showing no concerning toxicities.

• Proof-of-concept for pain indications will prioritize robust clinical models over variable healthy volunteer tests.