Poster
123
(#123) Effectiveness and Safety of Low-Sodium Oxybate in Participants With Idiopathic Hypersomnia With or Without Psychiatric Comorbidities: Results From the Phase 4 DUET Study
Psych Congress 2025
Abstract: Introduction: This post-hoc analysis of the DUET (Develop hypersomnia Understanding by Evaluating low-sodium oxybate Treatment) phase 4 trial (NCT05875974) evaluated effectiveness/safety of low-sodium oxybate (LXB; Xywav®) in participants with idiopathic hypersomnia with or without psychiatric comorbidities (PsychCM; per medical history).
Methods: DUET included screening, 8-day baseline (BL), 2-8-week LXB dose titration/optimization, 2-week stable-dose, 8-day end-of-treatment (EOT), and 2-week safety follow-up periods. Outcomes included Epworth Sleepiness Scale (ESS), Idiopathic Hypersomnia Severity Scale (IHSS), Patient Global Impression of Change (PGI-C), and Patient Health Questionnaire-9 (PHQ-9). Least squares mean (LSM) changes were adjusted for baseline values.
Results: Forty-six idiopathic hypersomnia participants enrolled; 26 had concurrent PsychCM (most commonly depression and anxiety). Most participants (with/without PsychCM) were female (84.6%/75.0%) and White (84.6%/85.0%); mean (SD) ages were 38.5 (12.1)/37.6 (11.7) years. Forty completed the study. Participants showed improved ESS and IHSS scores from BL to EOT-LSM changes (95% CI) were: ESS, with PsychCM −7.1 (−9.0, −5.1), without PsychCM −9.7 (−11.6, −7.8); IHSS, with PsychCM −12.7 (−17.1, −8.2), without PsychCM −18.1 (−22.3, −13.9). At EOT, over half of participants (with/without PsychCM) reported "much"/"very much" PGI-C improvement for overall disease (55.6%/84.2%), and a majority reported "none to minimal"/"mild" severity of depressive symptoms on PHQ-9 (80.0%/90.0%). Percentages of participants with/without PsychCM reporting ≥1 treatment-emergent adverse event (TEAE) were 69.2%/80.0%; common TEAEs included nausea, dizziness, and headache in both subgroups.
Conclusions: Results demonstrated effectiveness of LXB in participants with idiopathic hypersomnia, regardless of psychiatric comorbidities; TEAEs were consistent with the known LXB safety profile.
Short Description: This post hoc analysis of DUET (NCT05875974) evaluated the effectiveness/safety of low-sodium oxybate (LXB) treatment on idiopathic hypersomnia in participants with or without psychiatric comorbidities. LXB-treated participants in both subgroups demonstrated improvements in Epworth Sleepiness Scale and Idiopathic Hypersomnia Severity Scale scores. Both subgroups showed improvements in Patient Global Impression of Change for overall disease and Patient Health Questionnaire-9 scores. Treatment-emergent adverse events in both subgroups were consistent with the known LXB safety profile.
Name of Sponsoring Organization(s): Jazz Pharmaceuticals
Methods: DUET included screening, 8-day baseline (BL), 2-8-week LXB dose titration/optimization, 2-week stable-dose, 8-day end-of-treatment (EOT), and 2-week safety follow-up periods. Outcomes included Epworth Sleepiness Scale (ESS), Idiopathic Hypersomnia Severity Scale (IHSS), Patient Global Impression of Change (PGI-C), and Patient Health Questionnaire-9 (PHQ-9). Least squares mean (LSM) changes were adjusted for baseline values.
Results: Forty-six idiopathic hypersomnia participants enrolled; 26 had concurrent PsychCM (most commonly depression and anxiety). Most participants (with/without PsychCM) were female (84.6%/75.0%) and White (84.6%/85.0%); mean (SD) ages were 38.5 (12.1)/37.6 (11.7) years. Forty completed the study. Participants showed improved ESS and IHSS scores from BL to EOT-LSM changes (95% CI) were: ESS, with PsychCM −7.1 (−9.0, −5.1), without PsychCM −9.7 (−11.6, −7.8); IHSS, with PsychCM −12.7 (−17.1, −8.2), without PsychCM −18.1 (−22.3, −13.9). At EOT, over half of participants (with/without PsychCM) reported "much"/"very much" PGI-C improvement for overall disease (55.6%/84.2%), and a majority reported "none to minimal"/"mild" severity of depressive symptoms on PHQ-9 (80.0%/90.0%). Percentages of participants with/without PsychCM reporting ≥1 treatment-emergent adverse event (TEAE) were 69.2%/80.0%; common TEAEs included nausea, dizziness, and headache in both subgroups.
Conclusions: Results demonstrated effectiveness of LXB in participants with idiopathic hypersomnia, regardless of psychiatric comorbidities; TEAEs were consistent with the known LXB safety profile.
Short Description: This post hoc analysis of DUET (NCT05875974) evaluated the effectiveness/safety of low-sodium oxybate (LXB) treatment on idiopathic hypersomnia in participants with or without psychiatric comorbidities. LXB-treated participants in both subgroups demonstrated improvements in Epworth Sleepiness Scale and Idiopathic Hypersomnia Severity Scale scores. Both subgroups showed improvements in Patient Global Impression of Change for overall disease and Patient Health Questionnaire-9 scores. Treatment-emergent adverse events in both subgroups were consistent with the known LXB safety profile.
Name of Sponsoring Organization(s): Jazz Pharmaceuticals
