Measures of functional outcomes, work productivity, and quality of life from a randomized, phase 3 study of solriamfetol in participants with narcolepsy

Objective: Solriamfetol (formerly JZP-110), a dopamine/norepinephrine reuptake inhibitor, is approved in the US to improve wakefulness in adults with excessive daytime sleepiness associated with narcolepsy (75–150 mg/d) or obstructive sleep apnea (37.5–150 mg/d). In a randomized, double-blind, placebo-controlled trial in participants with narcolepsy, effects of solriamfetol on functional status, health-related quality of life (HRQoL), and work productivity were evaluated. Methods: Participants with narcolepsy (N = 239) were randomized to solriamfetol 75, 150, or 300 mg, or placebo for 12 weeks. Outcome measures included the Functional Outcomes of Sleep Questionnaire short version (FOSQ-10), 36-Item Short Form Health Survey version 2 (SF-36v2), and Work Productivity and Activity Impairment questionnaire for Specific Health Problem (WPAI:SHP). A mixed-effects model with repeated measures was used for comparisons vs placebo. Results: At week 12, solriamfetol increased FOSQ-10 total score, with greatest mean difference from placebo (95% CI) at 300 mg (1.45 [0.31, 2.59]). On SF-36v2, improvements vs placebo were observed in physical component summary scores (300 mg: 2.22 [0.04, 4.41]) and subscales of role physical, general health, and vitality. On WPAI:SHP, solriamfetol 150 mg reduced overall work impairment vs placebo (−15.5 [−29.52, −1.47]), and 150 and 300 mg reduced activity impairment vs placebo (−10.05 [−19.48, −0.62] and −13.49 [−23.19, −3.78], respectively). Most treatment-emergent adverse events (TEAEs) were mild or moderate in severity. Common TEAEs were headache, nausea, decreased appetite, nasopharyngitis, dry mouth, and anxiety. Conclusions: Solriamfetol improved measures of functional status, HRQoL, and work productivity, particularly at the 150- and 300-mg doses. Most TEAEs were mild to moderate. Trial registration: ClinicalTrials.gov identifier NCT02348593, EudraCT number 2014-005487-15.