Once-Nightly Sodium Oxybate (FT218) Demonstrated Improvement of Symptoms in a Phase 3 Randomized Clinical Trial in Patients With Narcolepsy.

STUDY OBJECTIVES To assess the efficacy and safety of FT218, a novel once-nightly formulation of sodium oxybate (ON-SXB), in patients with narcolepsy in the phase 3 REST-ON trial. METHODS Narcolepsy patients aged ≥16 years were randomized 1:1 to uptitration of ON-SXB (4.5, 6, 7.5, and 9 g) or placebo. Three coprimary endpoints were change from baseline in mean sleep latency on the Maintenance of Wakefulness test, Clinical Global Impression-Improvement rating, and weekly cataplexy attacks at 9, 7.5, and 6 g. Secondary endpoints included change from baseline on the Epworth Sleepiness Scale. Safety included adverse drug reactions and clinical laboratory assessments. RESULTS In total, 222 patients were randomized; 212 received ≥1 dose of ON-SXB (n=107) or placebo (n=105). For the 3 coprimary endpoints and Epworth Sleepiness Scale, all 3 doses of ON-SXB demonstrated clinically meaningful, statistically significant improvement vs placebo (all P<0.001). For ON-SXB 9 g vs placebo, increase in mean sleep latency was 10.8 vs 4.7 min (LSMD [95% CI], 6.13 [3.52-8.75]), 72.0% vs 31.6% were rated much/very much improved on Clinical Global Impression-Improvement (OR [95% CI], 5.56 [2.76-11.23]), change in mean weekly number of cataplexy attacks was -11.5 vs -4.9 (LSMD [95% CI], -6.65 [-9.32 to -3.98]), and change in Epworth Sleepiness Scale was -6.5 and -2.7 (LSMD [95% CI], -6.52 [-5.47 to -2.26]). Common adverse reactions included nausea, vomiting, headache, dizziness, and enuresis. CONCLUSIONS ON-SXB significantly improved narcolepsy symptoms; its safety profile was consistent with SXB. ON-SXB conferred efficacy with a clearly beneficial single nighttime dose.