Improvement in Bothersome Mood, Cognitive, and Functional Impacts of Idiopathic Hypersomnia After Low-Sodium Oxybate Treatment in the DUET Study
Background: A previous report of patient interviews identified bothersome idiopathic hypersomnia (IH) impacts, including mood disturbances, cognitive dysfunction, and personal/professional difficulties; evaluation of how IH treatment affects these impacts may help guide treatment decisions. We report the effectiveness of low-sodium oxybate (LXB; Xywav®) on mood and functional impairments in participants with IH from the DUET (Develop hypersomnia Understanding by Evaluating low-sodium oxybate Treatment) phase 4 trial (NCT05875974).
Design/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. Exploratory outcomes included self-reported depressive symptom severity (measured by the Patient Health Questionnaire-9 [PHQ-9]), cognitive complaints (measured by the British Columbia Cognitive Complaints Inventory [BC-CCI]), and work and activity impacts (measured by the Work Productivity and Activity Impairment Questionnaire: Specific Health Problem [WPAI:SHP]).
Results: Forty-six participants with IH (80.4% female; 84.8% White) enrolled and took ≥1 LXB dose after BL. Improvements (BL to EOT) were observed for depressive symptom severity (PHQ-9 change score; mean±SE, −5.9±0.6 [n=40]) and cognitive complaints (BC-CCI change score; mean±SE, −4.8±0.6 [n=40]). WPAI:SHP mean±SE changes (BL to EOT) were −4.6%±2.7% for absenteeism (n=29), −30.7%±4.3% for presenteeism (n=29), −32.4%±4.6% for overall work impairment (n=29), and −37.3%±4.7% for activity impairment (n=37) attributed to IH, representing reduced work and activity impairments. Treatment-emergent adverse events were consistent with the known safety profile of LXB.
Conclusions: Participants with IH taking open-label LXB reported improvements in highly bothersome impacts previously identified in qualitative patient interviews, including mood disturbances, cognitive dysfunction, and personal/professional difficulties.
