RESTORE: Once-Nightly Oxybate Dosing Preference and Nocturnal Experience with Twice-Nightly Oxybates

Objective /Background: Preference for extended-release, once-nightly sodium oxybate (ON-SXB, FT218) vs twice-nightly immediate-release (IR) oxybate was assessed in participants switching from IR oxybate to ON-SXB in an open-label/switch study, RESTORE (NCT04451668). Patients/Methods Participants aged ≥16 years with narcolepsy who completed the phase 3 REST-ON trial, were oxybate-naive, or were on a stable IR oxybate dose (≥1 month) were eligible for RESTORE. For participants who switched from twice-nightly dosing to ON-SXB, initial doses were closest or equivalent to their previous nightly IR oxybate dose. These participants completed a questionnaire at baseline about nocturnal adverse events associated with the middle-of-the-night IR oxybate dose in the preceding 3 months, a preference questionnaire after 3 months of stable-dose ON-SXB, and an end-of-study (EOS) questionnaire. Results There were 130 switch participants; 92/98 (93.9%) who completed the preference questionnaire preferred ON-SXB. At baseline, 69.2% reported missing their second IR oxybate dose at least once; in these cases, 80% felt worse the next day. Approximately 39% reported taking a second nightly IR oxybate dose >4 h after the first dose, 51% of whom felt somewhat to extremely groggy/unsteady the next morning; 120 participants (92%) reported getting out of bed after their second oxybate dose. Of those, 9 (8%) reported falls and 5 (4%) reported injuries. Of the switch participants who completed the EOS questionnaire, 91.2% felt better able to follow the recommended ON-SXB dosing schedule. Conclusions The second nightly IR oxybate dose presents significant treatment burdens and adherence concerns. Participants overwhelmingly preferred the once-nightly dosing regimen of ON-SXB.