Patient Preferences and Nocturnal Experiences With Oxybate Therapy for Narcolepsy: RESTORE Study Interim Analysis

This study was funded by Avadel Pharmaceuticals. Introduction: RESTORE (NCT04451668) is an ongoing open-label/switch study evaluating the safety/tolerability of once-nightly sodium oxybate (ON-SXB; LUMRYZ™) and patient preferences for ON-SXB or twice-nightly, immediate-release (IR) oxybate. Methods: Participants are aged ≥16 years with narcolepsy type 1/2 and completed the phase 3 REST-ON trial, were on stable-dose IR oxybate, or were oxybate-naive. At baseline, switch participants completed a nocturnal adverse event (AE) questionnaire about their IR oxybate experience and a preference questionnaire after 3 months of stable ON-SXB. Results: At the interim data cutoff (06 March 2023), 98 preference questionnaires and 130 nocturnal AE questionnaires were analyzed. The once-nightly dosing regimen was preferred by 93.9% (92/98) of participants. In the previous 3 months, the second nightly IR oxybate dose was unintentionally missed by 84 (65.1%) switch participants and/or was intentionally missed by 26 (20.1%); 80.0% (72/90) who intentionally/unintentionally missed the second dose felt worse the next day. Participants who took their second nightly IR oxybate dose >4 h after the first dose (n=51 [39.5%]) reported being somewhat, quite a bit, or extremely groggy/unsteady the next morning (26/51 [51.0%]). Inconvenience of the second dose was reported by 71.3%. Most common treatment-related AEs are nausea, somnolence, enuresis, headache, dizziness, and somnambulism. Conclusions: Interim RESTORE data show that 94% of participants switching from twice-nightly oxybate prefer the ON-SXB dosing regimen. A high proportion of participants had difficulty with taking the second nightly oxybate dose, which led to negative next-day consequences. ON-SXB may ease treatment burdens associated with the second nightly IR oxybate dose.