0751 Improvement in Sleepiness with Once-Nightly Sodium Oxybate in People with Narcolepsy Type 1 and Narcolepsy Type 2: A Specialty Pharmacy Data Analysis

Abstract Introduction Once-nightly sodium oxybate (ON-SXB; LUMRYZ™) is approved to treat excessive daytime sleepiness (EDS) or cataplexy in patients ≥7 years of age with narcolepsy. Findings from 2 studies have demonstrated improvements in objective and subjective EDS with ON-SXB in patients with narcolepsy type 1 (NT1) or 2 (NT2) (NCT02720744, NCT06792708). To evaluate the effect of ON-SXB on EDS in a larger, more diverse narcolepsy patient population, changes in Epworth Sleepiness Scale (ESS) score were analyzed using specialty pharmacy data. Methods Demographic/clinical data were collected from Optum Frontier Therapies pharmacy for adults with NT1 or NT2 with ≥1 filled ON-SXB prescription, ≥1 ON-SXB clinical assessment, and ≥1 follow-up ESS score (6/1/2023-9/30/2024). ESS total scores were assessed at baseline and at each follow-up assessment after ON-SXB initiation. ESS assessment participation was voluntary. Data were analyzed descriptively and stratified by narcolepsy subtype. Results Of 452 patients identified, 195 had ≥1 follow-up ESS score and reported narcolepsy type (NT1, n=123 63%; mean age, 38.6 years; female, 69%; NT2, n=72 37%; mean age, 40.7 years; female, 74%). More patients with NT1 vs NT2 (72% vs 58%) had any prior oxybate use. Baseline concomitant stimulant/wake-promoting agent use was 58% and 64% for NT1 and NT2, respectively. Mean (SD) ESS total scores at baseline were 12.1 (5.7) and 12.2 (5.3) for patients with NT1 and NT2, respectively; 31% of NT1 and 33% of NT2 had severe EDS. For both subtypes, mean (SD) ESS scores were within the normal EDS range (≤10) by the first follow-up (median time, 52 days; NT1, 10.0 5.5; NT2, 9.6 4.8). At first follow-up, more than half of patients in the NT1 (55%) and NT2 (54%) subgroups achieved normal levels (ESS total score ≤10) of sleepiness, while 20% of NT1 patients and 10% of NT2 patients had severe EDS. Mean (SD) change from baseline in ESS score was -2.1 (4.3) and -2.6 (5.3) in the NT1 and NT2 subgroups, respectively. Conclusion In this real-world dataset, both NT1 and NT2 patients quickly experienced clinically meaningful improvements in ESS score after initiating ON-SXB. These results support ON-SXB as an effective EDS treatment, regardless of narcolepsy subtype. Support (if any) Avadel Pharmaceuticals