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

OBJECTIVE

This study aimed to evaluate safety and efficacy of sodium oxybate (SXB) titrated to effect.

METHODS

SXB-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.

RESULTS

Of 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.

CONCLUSIONS

The SXB safety profile was consistent with parent trials. Ninety percent of patients reported improvements as measured by the NSAQ.