Exceptional Phase 3 XTOL-2 Efficacy
XTOL-2 met its primary endpoint with median percent change (MPC) in monthly focal seizure frequency of 53.2% (25 mg), 34.5% (15 mg) versus 10.4% for placebo; placebo-adjusted MPC for 25 mg ~42.8 percentage points. Company described this as exceeding expectations and surpassing prior Phase 2b results.
Strong Responder and Seizure Freedom Signals
Dose-dependent increases in responder rates including >=75% and >=90% reductions; 100% responder (RR100) for 25 mg was 6.5% over 12 weeks, increasing to 11.3% over the last 6 weeks and 13.7% over the last 4 weeks—evidence of building efficacy over time.
Robust Long-Term OLE Outcomes
48-month open-label extension showed a 91% reduction in monthly seizures for patients treated ≥48 months. Patients entering on 1–2 ASMs had a 100% reduction vs 82% for those on 3 ASMs. Among patients treated ≥48 months, ~40% were seizure-free for ≥12 months and ~25% were seizure-free for ≥2 years.
Consistent and Manageable Safety Profile
Safety and tolerability were consistent across XTOL and XTOL-2 with most common treatment-emergent adverse events being dizziness, somnolence, headache, and fatigue. Company cites >800 patient-years of safety/exposure data and characterizes profile as consistent with well-tolerated CNS-active ASMs.
Clear Regulatory and Commercial Pathway
Company plans NDA submission for AZK in 2026, anticipates a standard FDA review (~12 months) plus DEA scheduling (~3 months), implying expected launch in 2027 or early 2028 if timing holds. Pre-NDA interactions and continued FDA engagement planned.
Strong Balance Sheet and Funding Runway
Completed $747.5 million financing in Q1; cash, cash equivalents, and marketable securities of $1.3 billion vs $586 million at Dec 31, providing runway into 2029 to support commercial launch and ongoing programs.
Progress Across Broader Pipeline
Three Phase 3 depression studies (EXNOVA-2, EXNOVA-3, EXEDE) continue to enroll with EXNOVA-2 topline expected in 2027. First-in-human studies for pain programs XEN1701 (Nav1.7) and XEN1120 (Kv7) expected to complete this year with intent to advance to Phase II PoC in acute pain. Nav1.1 (Dravet) IND-enabling studies ongoing with strong preclinical data presented.
Strong Scientific and HCP Engagement
XTOL-2 data were accepted as a late-breaking oral presentation at AAN; company reported extensive positive feedback from hundreds of epileptologists and neurologists emphasizing efficacy magnitude, rapid onset, no titration, once-daily dosing, and no dose adjustments for other ASMs.