CLINICALLY MEANINGFUL IMPROVEMENT IN DAYTIME SLEEPINESS WITH ON-SXB IN PEOPLE WITH NARCOLEPSY AND SEVERE SLEEPINESS

Document Type

Conference Proceeding

Publication Date

5-19-2025

Publication Title

Sleep

Abstract

Introduction: Efficacy of once-nightly sodium oxybate (ON-SXB; LUMRYZ™) for narcolepsy was demonstrated in the phase 3 REST-ON trial (NCT02720744). Efficacy on daytime sleepiness in REST-ON participants with the most severe sleepiness at baseline was analyzed post hoc. Methods: Participants (≥16 years; narcolepsy type 1 [NT1] or NT2) were randomized 1:1 to ON-SXB (week 1, 4.5 g; weeks 2-3, 6 g; weeks 4-8, 7.5 g; weeks 9-13, 9 g) or placebo. Sleep latency on the Maintenance of Wakefulness Test (MWT) and Epworth Sleepiness Scale (ESS) scores were calculated in tertiles of participants from the modified intent-to-treat (mITT) population (randomized participants with ≥1 efficacy measurement after receiving 6-g dose) with lowest mean sleep latency on the MWT (MWT tertile) or highest ESS scores (ESS tertile) at baseline. Data are median (Q1, Q3) observed values. Results: In the mITT population (ON-SXB, n=97; placebo, n=93), mean age for MWT tertile participants (ON-SXB, n=33; placebo, n=30) was 30.5 years (65.1% female, 76.2% NT1, 60.3% taking concomitant alerting agents), and for ESS tertile participants (ON-SXB, n=33; placebo, n=41), it was 32.4 years (63.5% female, 90.5% NT1, 37.8% taking concomitant alerting agents). Respective sleep latency on the MWT (min) for ON-SXB and placebo groups of MWT tertile participants was 1.5 (1.0, 2.3) and 2.0 (1.3, 2.5) at baseline and 7.0 (2.5, 15.0) and 4.9 (1.8, 8.3) at week 13 (9 g), and for ESS tertile participants was 4.7 (2.8, 7.5) and 4.6 (2.1, 6.6) at baseline and 11.5 (6.9, 21.7) and 5.0 (2.0, 13.0) at week 13 (9 g). Respective ESS scores for ON-SXB and placebo groups of MWT tertile participants were 16.0 (14.0, 19.0) and 19.0 (16.0, 20.0) at baseline and 10.0 (6.0, 16.5) and 16.0 (13.0, 19.0) at week 13 (9 g), and of ESS tertile participants were 21.0 (19.0, 22.0) and 21.0 (19.0, 22.0) at baseline and 9.0 (6.0, 19.5) and 18.0 (14.0, 22.0) at week 13 (9 g). Conclusion: The most severely sleepy REST-ON participants at baseline experienced clinically meaningful improvement in daytime sleepiness with ON-SXB treatment, as ESS scores were at or below the normal threshold at the end of the study.

Volume

48

First Page

A361

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