Table 2.

Primary and key secondary endpoints (efficacy population)

Endpoint	Placebo (n = 65)	LXB (n = 69)
Change in weekly number of cataplexy attacks from SDP to DBRWP (primary efficacy endpoint)
Mean (SD)	11.46 (24.751)	0.12 (5.772)
Median	2.35	0.00
Q1, Q3	0.00, 11.61	−0.49, 1.75
Location shift*	−3.308
95% CI*	−6.044, −1.500
p value†	<0.0001
Change in ESS score from SDP to DBRWP (key secondary efficacy endpoint)
Mean (SD)	3.0 (4.68)	0.0 (2.90)
Median	2.0	0.0
Q1, Q3	0.0, 5.0	−1.0, 1.0
Location shift*	−2.00
95% CI*	−4.00, −1.00
p value‡	<0.0001

ANCOVA, analysis of covariance; CI, confidence interval; DBRWP, double-blind randomized withdrawal period; ESS, Epworth Sleepiness Scale; LXB, lower-sodium oxybate; Q1, first quartile; Q3, third quartile; SD, standard deviation; SDP, stable-dose period.

*Location shift between two treatment groups and asymptotic 95% CI from Hodges–Lehmann estimate (LXB–placebo).

^†From a rank-based ANCOVA model including the change in average weekly number of cataplexy attacks from the 2 weeks of the SDP to the 2 weeks of the DBRWP as response variable, prior treatment group and study treatment group as fixed effects, and average weekly number of cataplexy attacks during the 2 weeks of the SDP as covariate.

^‡From a rank-based ANCOVA model including the change in ESS total score from the end of the SDP to the end of the DBRWP as response variable, prior treatment group and study treatment group as fixed effects, and ESS total score at the end of the SDP as covariate.