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.