Long-Term Safety and Efficacy of Sodium Oxybate in Pediatric Patients With Narcolepsy: Evaluation of Depression, Anxiety, and Suicidal Risk

Introduction: Narcolepsy primarily begins in childhood/adolescence. Sodium oxybate (SXB) was evaluated as a treatment for narcolepsy in children/adolescents in a placebo-controlled, randomized-withdrawal study with open-label extension (OLE). The long-term evaluation of depression, anxiety, and suicidality in participants over 1 year is reported.

Methods: Children/adolescents (7-16 years at screening) with narcolepsy with cataplexy who were either taking SXB or SXB-naïve were enrolled. After a 2-week, double-blind, placebo-controlled, randomized-withdrawal period, participants entered an OLE period for up to 47 weeks (total duration, 1 year). Depression, anxiety, and suicidality were assessed using the Children’s Depression Inventory 2nd Edition Self-Report Short Version (CDI2:SR[S]), Multidimensional Anxiety Scale for Children 10-item (MASC-10), and Columbia-Suicide Severity Rating Scale (C-SSRS; children’s version <12 years, adult version ≥12 years). Participants with clinically significant psychiatric conditions at screening were excluded from the study.

Results: As of February 2017, 106 participants enrolled, 79 completed ≥6 months and 46 completed 1 year. Median (Q1, Q3) change from baseline in weekly number of cataplexy attacks at study end was 0.0 (-2.25, 4.17) with minimal change throughout. Mean CDI2:SR(S) and MASC-10 T-scores remained in the average range (41-59, 40-55, respectively) with a slight downward trend in CDI2:SR(S) over time. On C-SSRS, 1 participant developed suicidal ideation and was terminated from the study, and 1 participant developed acute psychosis and continued in the study, following resolution of the psychosis.

Conclusion: There was no evidence of increased risk of depression, anxiety, or suicidality over the 1-year study period of SXB for treatment of children/adolescents with narcolepsy.