CATEGORY: SLEEP & RECOVERY
What happens when you treat narcolepsy’s cause instead of its symptoms? Two international trials just answered. Among 273 people with narcolepsy type 1 who took the new pill oveporexton for 12 weeks, 48% to 69% scored in the normal range on a standard wakefulness test, compared with 0% to 6% on placebo, and weekly cataplexy attacks fell 79% to 89%.1
A Disease Defined by One Missing Chemical
Narcolepsy type 1 is a supply problem. The brain loses the small cluster of cells that make orexin, the chemical signal that holds you awake through the day. Without it, sleep crashes in at a desk, at dinner, behind the wheel. The same shortage causes cataplexy, sudden episodes of muscle weakness often set off by laughter. Older medicines push back with stimulants or sedatives. Oveporexton works differently. It’s a twice-daily pill that presses the same receptor orexin would have pressed, standing in for the signal the brain can no longer send. In August it became the first drug of this kind approved in the United States, under the brand name Orzeyful.
Staying Awake in a Dim, Quiet Room
The two trials, called FirstLight and RadiantLight, enrolled 168 and 105 people aged 16 to 70 across four continents. Nobody chose their treatment. A computer dealt each person the pill or a matching placebo, and neither patients nor doctors knew who had which. The main test was blunt and hard to fake: sit in a dim, quiet room and try to stay awake. People on oveporexton lasted 14 to 20 minutes longer than they had at the start. Placebo changed essentially nothing.1 Self-rated daytime sleepiness told the same story, with 67% to 84% of treated participants landing in the normal range by week 12.
The Price Was Mostly Sleep and Bathroom Trips
Side effects were common but rarely serious: insomnia, urinary urgency, and more frequent urination led the list, usually starting within the first two days and fading on their own. No liver damage appeared, and no meaningful changes in heart measures.1 Two participants developed rhabdomyolysis, a breakdown of muscle tissue, which the investigators tied to intense exercise. The trials lasted only 12 weeks in a lifelong disease, so durability is the open question. A longer extension study is under way, and nearly every participant chose to continue.
Key Takeaways
- Oveporexton is the first approved drug that targets the cause of narcolepsy type 1, the missing wake-promoting signal orexin, rather than treating sleepiness around it.
- Across two placebo-controlled trials, roughly half to two thirds of treated participants reached normal wakefulness and sleepiness scores within 12 weeks, and cataplexy attacks fell sharply.
- The most common side effects, insomnia and urinary symptoms, were mild to moderate and tended to fade; the trials were short, so long-term performance isn’t yet known.
References
- Dauvilliers Y, et al. Oveporexton for Narcolepsy Type 1—Results from Two Phase 3 Trials. N Engl J Med. 2026; published online September 9. doi:10.1056/NEJMoa2601598. link