0752 Once-Nightly Sodium Oxybate Improves Symptoms in People with Narcolepsy: Final Results from the Real-World REFRESH Study

Abstract Introduction Once-nightly sodium oxybate (ON-SXB; LUMRYZ™) is approved for excessive daytime sleepiness or cataplexy in patients ≥7 years of age with narcolepsy. REFRESH (NCT06792708) is a real-world study of ON-SXB in adults with narcolepsy. Methods Adults with narcolepsy who switched from twice-nightly oxybates (TN-OXB; switch) or were not taking oxybates upon study onset (not-oxybate-treated; ie, previous TN-OXB use or oxybate-naive) were eligible. ON-SXB was titrated in 1.5-g increments weekly or more gradually, based on efficacy/tolerability, to a maximum dose of 9 g/night. Participants completed the Epworth Sleepiness Scale (ESS), Narcolepsy Severity Scale (NSS), and Sheehan Disability Scale (SDS) monthly for 4 months. Patient and Clinician Global Impression of Change (PGI-C; CGI-C) were assessed at end-of-study (EOS). Adverse drug reactions (ADRs; ie, study drug-related adverse events) were reported. Results Of 86 participants screened, 71 initiated ON-SXB treatment (current TN-OXB use, n=25 [35%]; not-oxybate-treated, n=46 [65%; prior TN-OXB use, n=10 (22%); oxybate-naive, n=36 (78%)]); 51 completed the study. Respective mean (SD) ESS scores for switch and not-oxybate-treated participants were significantly improved from baseline (10.4 [5.4] and 14.9 [4.6]) vs month 4 (6.3 [3.9] and 8.5 [4.6)]; mean [SD] change from baseline: switch, -3.1 [2.9], P< 0.001; not-oxybate-treated, -6.6 [5.1], P< 0.001). Respective mean (SD) NSS scores for switch and not-oxybate-treated participants were moderate at baseline (16.0 [8.1] and 24.4 [9.8]) and mild at month 4 (9.8 [9.0] and 13.5 [9.1]; mean [SD] change from baseline: switch, -5.8 [6.0], P< 0.001; not-oxybate-treated, -10.9 [5.1], P< 0.001). Respective mean (SD) SDS scores for work/school, social life, and family life/home domains at baseline and month 4 were 4.3 (2.5) and 2.5 (2.4), 4.9 (2.6) and 3.0 (2.6), and 5.3 (2.6) and 3.2 (2.8) for switch and 6.0 (3.0) and 3.6 (2.8), 6.4 (2.6) and 3.6 (2.6), and 6.5 (2.8) and 3.6 (2.8) for not-oxybate-treated participants. At EOS, 70% and 76% of switch and 91% and 88% of not-oxybate-treated participants improved on PGI-C and CGI-C, respectively. ADRs were consistent with known oxybate ADRs. Conclusion ON-SXB treatment was associated with statistically and clinically significant improvements in symptoms, functional impairment, and burden of narcolepsy, regardless of direct switch from TN-OXB. Support (if any) Avadel Pharmaceuticals