Steininger, Teresa L.

Abstract Introduction Jazz DUET (Develop hypersomnia Understanding by Evaluating low-sodium oxybate Treatment) is a phase 4, prospective, multicenter, single-arm, multiple-cohort, open-label study (NCT05875974) assessing the effectiveness of low-sodium oxybate (LXB; Xywav®) treatment on daytime and nighttime symptoms in participants with narcolepsy (type 1 [NT1] or 2 [NT2]) or idiopathic hypersomnia. Data presented are from the narcolepsy cohort. Methods DUET included a screening period (with 2-week washout for current oxybate users), 8-day baseline (BL) period, 2- to 8-week LXB titration period, 2-week stable-dose period, 8-day end-of treatment (EOT) period, and 2-week safety follow-up. The primary endpoint was change in Epworth Sleepiness Scale (ESS) score from BL to EOT. Key secondary endpoints for the narcolepsy cohort included change in polysomnography parameters: total shifts from deeper to lighter sleep stages, stage N3 sleep duration (minutes), and number of awakenings. Additional endpoints included Patient Global Impression of Change (PGIc)–overall narcolepsy disease. Primary and key secondary endpoints were controlled for multiplicity with sequential testing; other P-values are considered nominal. Results Fifty-five narcolepsy participants enrolled and were dosed with LXB (NT1, n=26; NT2, n=29); 13 transferred to another cohort and 34 were completers (NT1, n=16; NT2, n=18). Enrolled participants were mostly female (72.7%) and White (80.0%); mean (SD) age was 33.4 (12.9) years (NT1=34.6 [12.6]; NT2=32.4 [13.2]). For completers, least-squares mean (LSM) (SE) changes in ESS score were −7.7 (0.9), P<.0001, overall; NT1=−6.5 (1.4), P<.0001; NT2=−8.8 (1.3), P<.0001. Compared with BL, sleep architecture at EOT showed fewer deeper to lighter sleep stage shifts (LSM [SE]: −13.1 [2.9], P<.0001, overall; NT1=−13.9 [4.3], P=0.0029; NT2=−12.3 [4.1], P=0.0050); increased stage N3 sleep (minutes) (45.0 [8.8], P<.0001, overall; NT1=49.8 [13.0], P=0.0006; NT2=40.8 [12.3], P=0.0023); and fewer awakenings (−3.2 [0.9], P=0.0015, overall; NT1=−4.1 [1.4], P=0.0056; NT2=−2.3 [1.3], P=0.0771). Most participants (93.3%, n=30; NT1, 86.7%, n=15; NT2, 100%, n=15) reported improvement (very much, much, minimally) in overall narcolepsy disease on PGIc. Treatment-emergent adverse events were consistent with the known safety profile of LXB. Conclusion Participants with NT1 and NT2 taking open-label LXB showed improvements in daytime sleepiness (decreased ESS scores) and reduced symptom burden (improved PGIc), which paralleled improvements in sleep architecture and disruption. Support (if any) Jazz Pharmaceuticals

Abstract Introduction Introduction: Jazz DUET (Develop hypersomnia Understanding by Evaluating low-sodium oxybate Treatment) is a phase 4, prospective, multicenter, single-arm, multiple-cohort, open-label study (NCT05875974) evaluating the effectiveness of low-sodium oxybate (LXB, Xywav®) treatment on daytime and nighttime symptoms, including excessive daytime sleepiness (EDS) and polysomnography in participants with idiopathic hypersomnia (IH) or narcolepsy. Data presented are from the IH cohort. Methods DUET included screening (with 2-week washout for 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. The primary endpoint was change in Epworth Sleepiness Scale (ESS) score from BL to EOT. Secondary endpoints for the IH cohort included change in Idiopathic Hypersomnia Severity Scale (IHSS) total score, Patient Global Impression of Change (PGIc)−overall IH disease, PGIc−sleep inertia, and Patient Global Impression of Severity (PGIs)−sleep inertia. Exploratory endpoints included IHSS component scores (daytime functioning, sleep inertia). Primary and key secondary (IHSS total score) endpoints were controlled for multiplicity with sequential testing; all other P-values are considered nominal. Results Forty-six people with IH enrolled and were dosed with LXB; 40 were completers. Enrolled participants were mostly female (80.4%) and White (84.8%), with a mean (SD) age of 38.1 (11.8) years. For completers, BL mean (SD) ESS score and IHSS total score were 16.5 (2.7) and 32.9 (7.1), respectively; least-squares mean (LSM) (SE) changes from BL to EOT were −8.4 (0.7), P<.0001 and −15.5 (1.5), P<.0001. BL mean (SD) IHSS component scores for daytime functioning and sleep inertia were 17.7 (4.2) and 10.7 (3.1), respectively; LSM (SE) changes from BL to EOT were −8.8 (1.0), P<.0001 and −4.8 (0.4), P<.0001. At EOT, most participants reported improvement (very much, much, minimally) on PGIc−overall IH disease (94.6%) and PGIc−sleep inertia (81.1%). At BL, 25.0% of participants reported sleep inertia severity as very mild/mild/not present on PGIs–sleep inertia vs 59.0% at EOT. Treatment-emergent adverse events were consistent with the known safety profile of LXB. Conclusion People with IH taking open-label LXB showed improvements in EDS and sleep inertia (decreased ESS and IHSS component scores) and reported reduced multi-symptom burden (decreased IHSS total scores and improved PGIc/PGIs ratings). Support (if any) Jazz Pharmaceuticals

Abstract Introduction Jazz DUET (Develop hypersomnia Understanding by Evaluating low-sodium oxybate Treatment) is a phase 4, prospective, multicenter, single-arm, multiple-cohort, open-label study (NCT05875974) evaluating the effectiveness of low-sodium oxybate (LXB, Xywav®) treatment on outcomes including sleep quality (using polysomnography [PSG] and self-reported questionnaires) in participants with narcolepsy or idiopathic hypersomnia. Data reported here are from the narcolepsy cohort. Methods DUET included a screening period (with 2-week washout for current oxybate users), an 8-day baseline (BL) period, a 2- to 8-week LXB titration period, a 2-week stable-dose period (SDP), an 8-day end-of-treatment (EOT) period, and a 2-week safety follow-up. Participants underwent nocturnal PSG (ad libitum protocol) at BL and EOT. The Karolinska Sleepiness Scale (KSS) was administered 90 minutes post-awakening from PSG to measure situational sleepiness (9-point scale; 1=“extremely alert” to 9=“extremely sleepy, can’t keep awake”). Participants completed an electronic sleep diary (eDiary) daily during the BL and EOT periods, including questions regarding nightly sleep patterns, total sleep time (TST), sleep quality (5-point scale; “very good” to “very poor”), and how rested/refreshed the participant felt upon awakening (5-point scale; “very well” to “not at all”). Completion of ≥5 eDiary days during the 8-day assessment before PSG visits was required for analysis. eDiary and KSS data were analyzed in the completer set (enrolled participants who were dosed with LXB and completed SDP and PSG at EOT). Results Fifty-five participants with narcolepsy (type 1, n=26; type 2, n=29) enrolled (completer set, n=34). Most were female (40/55; 73%) and White (44/55; 80%); mean (SD) age was 33.4 (12.9) years. Mean (SD) self-reported nocturnal TST at BL (n=32) and EOT (n=20) was 8.1 (1.6) and 8.3 (0.9) hours, respectively. The percent of participants rating their sleep quality as “very good”/“good” increased from 15.6% (BL) to 70.0% (EOT). The percent of participants with rested sleep (“very well”/“well”/“somewhat” rested) increased from 46.9% (BL) to 90.0% (EOT). Likewise, mean (SD) rating of self-reported sleepiness decreased from 5.1 (2.0) at BL to 3.8 (1.9) at EOT. Conclusion Following open-label LXB treatment, participants with narcolepsy reported improvements in sleep quality and feeling more rested and less sleepy upon awakening. Support (if any) Jazz Pharmaceuticals

Abstract Introduction Jazz DUET (Develop hypersomnia Understanding by Evaluating low-sodium oxybate Treatment) is a phase 4, prospective, multicenter, single-arm, multiple-cohort, open-label study (NCT05875974) evaluating effectiveness of low-sodium oxybate (LXB, Xywav®) treatment on outcomes including polysomnography (PSG)-based sleep architecture in participants with idiopathic hypersomnia or narcolepsy (type 1 [NT1] or 2 [NT2]). Methods DUET included a screening period (2-week washout for current oxybate users), 8-day baseline (BL) period, 2- to 8-week LXB titration period, 2-week stable-dose period (SDP), 8-day end-of-treatment period (EOT), and 2-week safety follow-up. Participants underwent nocturnal PSG (ad libitum protocol) at BL and EOT. PSGs were scheduled to allow a minimum of 10 hours in bed, unless the participant naturally awakened earlier; bedtime was determined by habitual bedtime. PSG recordings were centrally scored. Data were analyzed for participants in the narcolepsy cohort completer set. Total shifts from deeper to lighter sleep stages was defined as N1/N2/N3/REM to wake and N2/N3/REM to N1. Key secondary endpoints (total stage shifts, N3 duration) were controlled for multiplicity with sequential testing; other P-values are considered nominal. Results Fifty-five participants with narcolepsy enrolled (NT1, n=26; NT2, n=29); 34 completed the study (NT1, n=16; NT2, n=18). Most were female (73%) and White (80%) (mean±SD age, 33.4±12.9 years). Mean±SD total sleep time (TST) at BL/EOT was 453.2±80.1/452.4±70.0 minutes (LSM change [95% CI]: –0.78 [–23.7, 22.1]; P=.9451). Mean±SD number of total shifts from deeper to lighter sleep stages at BL/EOT was 54.6±28.0/41.6±25.6 (LSM [95% CI]: –13.1 [–19.0, –7.1]; P<.0001 [controlled for multiplicity]). Mean±SD time spent in N1 at BL/EOT was 45.3±28.4/37.2±25.2 minutes (LSM [95% CI]: –8.1 [–14.9, –1.4]; P=.0196), % of stage was 10.4%/8.2% (P=.0037); in N2 was 241.8±61.2/243.3±76.1 minutes (LSM [95% CI]: 1.5 [–23.6, 26.6]; P=.9040), 53.1%/53.2% (P=.9869); in N3 was 61.1±34.8/106.1±69.5 minutes (LSM [95% CI]: 45.0 [27.0, 63.0]; P<.0001 [controlled for multiplicity]), 13.7%/24.0% (P<.0001); and in REM was 105.0±42.7/65.8±33.1 minutes (LSM [95% CI]: –39.2 [–50.8, –27.5]; P<.0001), 22.8%/14.7% (P<.0001). Conclusion Participants with narcolepsy taking open-label LXB showed negligible change in TST and N2, increased N3, decreased N1 and REM, and fewer shifts from deeper to lighter stages of sleep. Support (if any) Jazz Pharmaceuticals