Original ArticleA 12-week open-label, multicenter study evaluating the safety and patient-reported efficacy of sodium oxybate in patients with narcolepsy and cataplexy

•Narcolepsy Symptom Assessment Questionnaire evaluated efficacy of SXB treatment.•Response was defined as “much improved” or “somewhat improved” at 6 and 12 weeks.•Patients taking SXB reported improvement in narcolepsy symptoms at 6 and 12 weeks.•Patients taking SXB reported improvements in sleep quality and ability to concentrate.

ObjectiveThis study aimed to evaluate safety and efficacy of sodium oxybate (SXB) titrated to effect.MethodsSXB-naive patients who had participated in a randomized SXB clinical trial and had not been titrated to adequate clinical effect were initiated on open-label SXB at 4.5 g/night and titrated in 1.5-g increments to 6, 7.5, or 9 g/night or down to 3 g/night, based on individual clinical response. Treatment was 12 weeks; safety was the primary outcome. Efficacy was evaluated using the Narcolepsy Symptom Assessment Questionnaire (NSAQ), a five-point scale (“much improved” to “much worse”) that assessed changes from baseline in specific symptoms. Response was defined as “much improved” or “somewhat improved” overall at weeks 6 and 12.ResultsOf 202 patients, 171 (85%) completed treatment; final doses were 3 g (n = 5), 4.5 g (n = 29), 6 g (n = 80), 7.5 g (n = 66), and 9 g (n = 22). Adverse events (AEs) were reported in 114 patients (56%), serious AEs in five (2%). The most common AEs were nausea (10%), headache (7%), and dizziness (5%). Response rate was 92% at week 6 and 90% at week 12; most patients reported improvements in all individual symptoms. Overall, 60% of patients rated their symptoms at 12 weeks as “much improved,” and this improvement was dose dependent.ConclusionsThe SXB safety profile was consistent with parent trials. Ninety percent of patients reported improvements as measured by the NSAQ.