Efficacy and safety of selective orexin 2 receptor agonists in narcolepsy type 1: a systematic review and meta-analysis of randomized controlled trials.
Lu Yuan, Yan-Bing Huang, Yi-Xuan Chen et al.
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In 30 seconds
This systematic review and meta-analysis pooled randomized, double-blind, placebo-controlled trials of oral selective orexin 2 receptor agonists in people with narcolepsy type 1. Five trials randomized 550 participants; the primary efficacy analysis included 337 and covered 6–12 weeks of treatment with TAK-994, oveporexton, or alixorexton. Compared with placebo, treatment increased Maintenance of Wakefulness Test sleep latency by 22.7 min (95% CI 16.8-28.7) and reduced Epworth Sleepiness Scale scores and weekly cataplexy rates. Urinary symptoms, insomnia, and salivary hypersecretion were more frequent; the TAK-994 program ended after hepatotoxicity.
Key findings
- OX2R agonists increased Maintenance of Wakefulness Test sleep latency by 22.7 min (95% CI 16.8-28.7; low-certainty evidence).
- Epworth Sleepiness Scale scores fell by a mean of 9.8 points (95% CI - 10.9 to - 8.8; moderate-certainty evidence).
- Weekly cataplexy rates were reduced by 69% (incidence rate ratio, 0.31; 95% CI 0.23-0.41; moderate-certainty evidence).
- Urinary frequency, insomnia, urinary urgency, and salivary hypersecretion were more frequent with treatment; TAK-994 development was terminated after hepatotoxicity.
Why it matters
The pooled results suggest that targeting OX2R can improve three clinically relevant manifestations of narcolepsy type 1: impaired wakefulness, daytime sleepiness, and cataplexy. The findings also highlight adverse effects and a hepatotoxicity signal in the TAK-994 program, underscoring that efficacy should be considered alongside safety and that evidence across compounds remains limited.
What to keep in mind
Only five trials were included, treatment lasted 6–12 weeks, and Maintenance of Wakefulness Test results showed substantial heterogeneity. The authors note that limited trials and short follow-up constrain class-wide and long-term safety conclusions.