Presentation (CTI)

OBJECTIVES: Jazz DUET (Develop hypersomnia Understanding by Evaluating low-sodium oxybate Treatment) (NCT05875974) is a phase 4, prospective, multicenter, single-arm, multiple-cohort, open-label study evaluating the effectiveness of low-sodium oxybate (LXB; calcium, magnesium, potassium, and sodium oxybates) on daytime sleepiness and functional status, including work productivity and daily activities, in people with idiopathic hypersomnia or narcolepsy (2 separate cohorts).
METHODS: DUET comprised 2- to 6-week screening (with 2-week washout for current oxybate users), 8-day baseline (BL), 2- to 8-week LXB titration, 2-week stable-dose, 8-day end of treatment (EOT), and 2-week safety follow-up periods. Exploratory outcomes included the Functional Outcomes of Sleep Questionnaire-10 (FOSQ-10) and Work Productivity and Activity Impairment Questionnaire: Specific Health Problem (WPAI:SHP), both administered at BL and EOT.
RESULTS: Forty-six participants with idiopathic hypersomnia (80.4% female; 84.8% White; mean [SD] age, 38.1 [11.8] years) and 55 with narcolepsy (72.7% female, 80.0% White; mean [SD] age, 33.4 [12.9] years) enrolled and took ≥1 dose of LXB after BL. At study entry, 9/46 participants with idiopathic hypersomnia and 13/55 with narcolepsy were taking oxybate and washed out before BL. BL FOSQ-10 mean (SD) scores for idiopathic hypersomnia and narcolepsy, respectively, were 11.8 (2.8) and 11.4 (3.0); mean (SD) changes from BL to EOT were 3.3 (2.7) and 2.9 (2.7), respectively. BL WPAI:SHP mean (SD) values for idiopathic hypersomnia and narcolepsy, respectively, were 59.8% (19.0%) and 61.3% (23.4%) for overall work impairment and 67.5% (19.4%) and 56.2% (21.0%) for non-work-related activity impairment; mean (SD) changes from BL to EOT were −32.4% (24.6%) and −36.1% (22.2%) for overall work impairment and −37.3% (28.8%) and −23.7% (25.0%) for non-work-related activity impairment, respectively. Treatment-emergent adverse events were consistent with the known safety profile of LXB.
CONCLUSIONS: Open-label LXB was associated with improvements from BL impairment in functional status, overall work productivity, and non-work-related activities.