0575 Cataplexy Response With FT218 (Once-Nightly Sodium Oxybate): Post Hoc Responder Analysis From the Phase 3 Rest-ON Clinical Trial

Abstract Introduction In the phase 3 REST-ON trial (NCT02720744), participants with narcolepsy type 1 (NT1) treated once-nightly sodium oxybate (ON-SXB; FT218), an investigational, extended-release formulation, had significant reductions in cataplexy episodes (ON-SXB vs placebo: 4.5 g, P< 0.05 [post hoc]; 6 , 7.5, and 9 all 0.001). This post hoc responder analysis further characterized improvements mean weekly participants. Methods REST-ON, aged ≥16 years NT1/NT2 were randomized 1:1 to double-blind ON-SXB or placebo for 13 weeks. Participants took g (1 week), (2 weeks), 7.5 (5 weeks). NT1 recorded number of per day (0, 1, 2, 3, 4, ≥5) a diary. Percentage ≥25%, ≥50%, ≥75%, 100% from baseline compared placebo; Fisher exact test). Results modified intent-to-treat population, 145 (ON-SXB, n=73; placebo, n=72). Baseline (SD) was 18.9 (8.7) group 19.8 (8.9) placebo. At week (4.5 g), significantly more taking ≥25% reduction (43.8% 26.4%; 0.05). Significantly receiving ≥75% at weeks 8, complete resolution 8 (6-g dose: 68.5% 40.3% [P< 0.001]; 38.4% 20.8% 0.05]; 23.3% 4.2% [P=0.001]; 100%, 2.7% 0 [P=NS]; 7.5-g 67.1% 43.1%; 53.4% 25.0%; 32.9% 8.3% [all 6.8% 9-g 58.9% 41.7% 49.3% 26.4% 15.3% 0.01]; 11.0% 2.8% 0.05]). Conclusion this post-hoc analysis, reduced by 1. Additionally, ~10% free episodes. These data may be useful clinicians when setting expectations effectiveness patients cataplexy. Support (if any) Avadel Pharmaceuticals