This study aims to assess patient preference for once- vs twice-nightly oxybate dosing regimens and experiences with the second dose of twice-nightly, immediate-release (IR) oxybate.
IR oxybates require patients with narcolepsy to awaken for a second dose 2.5–4 hours after the bedtime dose. RESTORE, an ongoing open-label/switch study (NCT04451668), evaluates long-term safety/tolerability of investigational, extended-release once-nightly sodium oxybate (FT218; ON-SXB).
Participants aged ≥16 years with narcolepsy type 1 or 2 who completed the phase 3 REST-ON trial, were on stable-dose (≥1 month) IR oxybate, or were oxybate-naive were eligible. For those switching to ON-SXB, initial doses were equivalent/closest to the previous total IR oxybate dose/night; adjustments were allowed in 1.5-g increments/week. Switch participants completed the nocturnal adverse event (AE) questionnaire about their IR oxybate experience at baseline and preference questionnaire 3 months after switching to ON-SXB. Safety and dose titration data are presented separately.
RESTORE enrollment completed 30June2022. At the interim data cutoff (01July2022), 78 switch participants completed preference questionnaires; 130 completed nocturnal AE questionnaires. Preference for the ON-SXB dosing regimen was stated by 93.6% (73/78) of participants. On the nocturnal AE questionnaire, 65.4% (85/130) unintentionally missed their second IR oxybate dose in previous 3 months; of participants who intentionally and/or unintentionally missed the second dose, 80.2% (73/91) felt worse the next day. Second nightly IR oxybate doses were taken >4 h after the first by 39.2% (51/130); 51.0% (26/51) were somewhat to extremely groggy/unsteady the next morning. The second dose was rated somewhat to extremely inconvenient for 70.8%. Second-dose-related anxiety (29.2%) and need for someone to wake them (23.1%) were also reported. Most (90.8% [118/130]) arose from bed when waking for the second dose; 9 had falls and 5 reported injuries.
These data indicate patient preference for once-at-bedtime dosing and reveal the treatment burden of twice-nightly IR oxybate.