Poster
114
(#114) Safety and Tolerability of Once-Nightly Sodium Oxybate: A Post Hoc Analysis From the Long-Term RESTORE Study
Psych Congress 2025
Abstract: Introduction: Long-term safety and tolerability of once-nightly sodium oxybate (ON-SXB) were investigated in the open-label/switch study RESTORE (NCT04451668).
Methods: Participants ≥16 years of age with narcolepsy who completed the phase 3 REST-ON trial (without initiating a twice-nightly oxybate [TN-OXB]), were on TN-OXB for ≥1 month, or were oxybate naive were enrolled. Participants who completed REST-ON (without initiating TN-OXB) or were oxybate naïve initiated ON-SXB at 4.5 g/night and increased weekly by 1.5 g/night as needed up to 9 g/night during a 1- to 2-month titration period. Long-term safety data from these participants were collected over the ≥3-year study duration.
Results: Among the 50 participants not taking an oxybate at enrollment (mean age, 33 years; female, 60%; white, 80%; mean [range] ON-SXB treatment, 408.1 [8-1098] days), 76% reported ≥1 TEAE; most were mild (36%) or moderate (36%) in severity. TEAEs occurring in ≥10% of participants included nausea (26%), COVID-19 (12%), somnolence (12%), dizziness (10%), vomiting (10%), sinusitis (10%), and tremor (10%). One participant reported ≥1 serious AE considered related to ON-SXB treatment (anxiety, delusional thoughts), leading to ON-SXB discontinuation. ADRs were reported by 56% of participants. ADRs occurring in ≥10% of participants included nausea (24%), somnolence (12%), and dizziness (10%). Seven (14%) participants experienced ≥1 ADR that led to ON-SXB discontinuation, including nausea, which led to discontinuation in 2 participants.
Conclusion: These data demonstrate that participants not taking TN-OXB tolerated ON-SXB well, as TEAEs were primarily mild/moderate in severity. ADRs aligned with the known oxybate safety profile.
Short Description: Oxybates are effective and guideline-recommended pharmacologic treatment options for narcolepsy. The open-label/switch study RESTORE evaluated the long-term safety and tolerability of once-nightly sodium oxybate (ON-SXB) in people with narcolepsy. Most treatment-emergent adverse events reported by participants were mild or moderate in severity. The most common adverse drug reactions included nausea, somnolence, and dizziness. These data indicate that ON-SXB was well tolerated, and the safety profile of ON-SXB aligned with the known oxybate safety profile.
Name of Sponsoring Organization(s): Avadel Pharmaceuticals
Methods: Participants ≥16 years of age with narcolepsy who completed the phase 3 REST-ON trial (without initiating a twice-nightly oxybate [TN-OXB]), were on TN-OXB for ≥1 month, or were oxybate naive were enrolled. Participants who completed REST-ON (without initiating TN-OXB) or were oxybate naïve initiated ON-SXB at 4.5 g/night and increased weekly by 1.5 g/night as needed up to 9 g/night during a 1- to 2-month titration period. Long-term safety data from these participants were collected over the ≥3-year study duration.
Results: Among the 50 participants not taking an oxybate at enrollment (mean age, 33 years; female, 60%; white, 80%; mean [range] ON-SXB treatment, 408.1 [8-1098] days), 76% reported ≥1 TEAE; most were mild (36%) or moderate (36%) in severity. TEAEs occurring in ≥10% of participants included nausea (26%), COVID-19 (12%), somnolence (12%), dizziness (10%), vomiting (10%), sinusitis (10%), and tremor (10%). One participant reported ≥1 serious AE considered related to ON-SXB treatment (anxiety, delusional thoughts), leading to ON-SXB discontinuation. ADRs were reported by 56% of participants. ADRs occurring in ≥10% of participants included nausea (24%), somnolence (12%), and dizziness (10%). Seven (14%) participants experienced ≥1 ADR that led to ON-SXB discontinuation, including nausea, which led to discontinuation in 2 participants.
Conclusion: These data demonstrate that participants not taking TN-OXB tolerated ON-SXB well, as TEAEs were primarily mild/moderate in severity. ADRs aligned with the known oxybate safety profile.
Short Description: Oxybates are effective and guideline-recommended pharmacologic treatment options for narcolepsy. The open-label/switch study RESTORE evaluated the long-term safety and tolerability of once-nightly sodium oxybate (ON-SXB) in people with narcolepsy. Most treatment-emergent adverse events reported by participants were mild or moderate in severity. The most common adverse drug reactions included nausea, somnolence, and dizziness. These data indicate that ON-SXB was well tolerated, and the safety profile of ON-SXB aligned with the known oxybate safety profile.
Name of Sponsoring Organization(s): Avadel Pharmaceuticals
