0765 Oxybate Treatment Experience and Preferences of People with Idiopathic Hypersomnia

Abstract Introduction Treatment options for idiopathic hypersomnia (IH) are limited. Oxybate treatment experiences and preferences of people with IH were characterized using survey data. Methods Surveys were fielded in 2 phases to respondents recruited from Facebook and Reddit (1/23/2025-3/19/2025) and from Rare Patient Voice members and patients who were provided the link by their clinician (7/28/2025-8/5/2025). Respondents were required to live in the US, be aged ≥18 years, report clinician-diagnosed IH, and be currently/previously receiving an oxybate. Results Fifty respondents (female, 96%; age range, 19-66 years) completed the survey. Mean and median time from symptom onset to diagnosis was 10 and 13 years, respectively (range, < 1-37 years). When considering IH treatment, ability to reduce frequency/intensity of excessive daytime sleepiness; improve general health, intellectual functioning, and/or mood; and improve the transition from sleep to wake were rated ≥7 on a 9-point scale (1=not important; 9=extremely important) by 84%, 74%, and 64% of respondents, respectively. Immediate-release (IR) calcium/magnesium/potassium/sodium oxybates was the most common current/previous oxybate taken (84%), followed by IR sodium oxybate (24%); 4% of respondents had previously taken both. IR oxybates were most often prescribed as a twice-nightly regimen (72%); 12% of respondents were prescribed a single IR oxybate dose; 16% were prescribed both single and twice-nightly regimens at some point. Of respondents taking twice-nightly doses, 72% took equal first and second doses (total nightly dose: < 4.5 g, 6%; 4.5-5.9 g, 19%; 6-7.4 g, 8%; 7.5-9 g, 39%), 25% took asymmetric doses, and 1 did not recall their dose. Of 30 respondents (60%) who accidentally missed their second oxybate dose, 47% missed ≥1 dose/week. Consequences of missed doses were extreme sleepiness, brain fog, migraines, and functional impairment. Respondents reported mistimed doses: 36% took their second dose >4 hours and 10% took their second dose < 2.5 hours after the first dose. More than two-thirds of respondents agreed or strongly agreed that a single, premeasured, extended-release bedtime dose of sodium oxybate would be safer/more convenient than current treatment options. Conclusion These survey data from people with IH identified delayed diagnoses, challenges with IR oxybates, and a desire for extended-release, once-nightly sodium oxybate. Support (if any) Avadel Pharmaceuticals