woman narcolepsy

“What clinical effects were seen for cataplexy in adult narcolepsy?”

XYREM demonstrated continued efficacy for cataplexy after long-term use.1,2

The results of the XYREM Trial N2 showed...

  • Patients randomized to placebo experienced a significant median increase of cataplexy attacks (P<0.001).1,2
  • Patients maintained on XYREM at established dosages experienced no median change in the number of cataplexy attacks.2
  • No effect was seen in patients treated with dosages of less than 6 g per night, suggesting little effect at these dosages.1


Median Changes in Weekly Cataplexy Frequency1,2


Maintained on XYREM (n = 26)

Randomized to placebo (n = 29)

Baseline median cataplexy frequency over 2-week lead-in phase:

XYREM = 1.9

Placebo = 4.0

Trial N2 Study Description

Study Design1-3

  • Randomized, double-blind, placebo-controlled, multicenter trial
  • Assessed the long-term efficacy of orally administered XYREM compared with placebo
  • Compared effects of continuing established dosages of 3 g, 4.5 g, 6 g, 7.5 g, or 9 g per night with placebo after a 2-week, single-blind, lead-in baseline phase

Patients Studied1,2

  • 55 narcolepsy patients with inclusion criteria featuring:
    • A history of 5 or more cataplexy attacks per week prior to receiving any treatment for cataplexy
    • Continuous treatment with XYREM for at least 6 months prior to study

Baseline Characteristics1,3

  • Mean age: 47.7 years
  • Median frequency of cataplexy attacks over 2 weeks: 3.0
    • Range: 0 to 197
  • Mean duration of prior treatment with XYREM: 21 months
    • Range: 7 to 44 months
  • Dosages at screening:
    • 6 g to 9 g per night (80% of patients)
    • 3 g or 4.5 g per night (4% and 16% of patients, respectively)
  • 80% were taking concomitant stimulant medications


  • Evaluate the continued efficacy of XYREM after long-term use for the treatment of cataplexy in patients with narcolepsy

Primary Efficacy Measure2,3

  • Change in number of cataplexy attacks from baseline (2-week, single-blind, lead-in phase) to end point (2-week, double-blind treatment phase)

Trial N2 Study Design Flowchart1-3

Xyrem efficacy in cataplexy n2 study design flowchart
  • At the end of the baseline phase, patients were randomized to continue their established dosage (from 3 g to 9 g per night) or placebo.
  • Patients using anticataplectic medications other than XYREM during the 30-day period prior to study entry were excluded.
  • Patients were allowed to continue the concomitant use of stimulant medications.

Patients randomized to placebo experienced a significant median increase of 21 cataplexy attacks over the entire 2-week, double-blind period, compared with no median increase observed in patients maintained on XYREM (P<0.001).1-3