Daridorexant phase 2 data put paediatric insomnia on the development map
Idorsia has presented full phase 2 results for its orexin receptor antagonist in children and adolescents with insomnia. The trial was short and the effect modest, but it is a rare controlled study in a field that relies on off-label prescribing.
In brief
Idorsia's phase 2 trial of daridorexant in 165 young people with insomnia met its primary endpoint. A phase 3 programme is planned for late 2027.
- The dose-finding trial randomised 165 patients aged 10 to under 18 to daridorexant 10, 25 or 50 mg, or placebo, for two weeks.
- On the first night, total sleep time rose by about 50 minutes on 50 mg against about 20 minutes on placebo.
- Idorsia expects to start a paediatric phase 3 programme in the second half of 2027.
Idorsia has presented the full results of its phase 2 trial of daridorexant in children and adolescents with insomnia disorder at the Sleep Europe 2026 congress. The Swiss company announced the data on 23 October 2026, after reporting topline results in March.
Daridorexant, a dual orexin receptor antagonist, is marketed for adults as Quviviq in North America and Europe. Paediatric use remains investigational and is not approved in any country. The study forms part of an FDA-agreed paediatric study plan and a paediatric investigation plan agreed with the EMA's Paediatric Committee.
The trial
The randomised, double-blind, placebo-controlled dose-finding study enrolled 165 patients aged 10 to under 18 with insomnia disorder as defined in DSM-5. About four in five were aged 12 to 17. They were randomised equally to daridorexant 10, 25 or 50 mg, or placebo, for two weeks. More than half had a diagnosed or subthreshold neurodevelopmental disorder, such as autism or attention deficit hyperactivity disorder (ADHD).
The primary endpoint was the change in total sleep time on the first night, measured by polysomnography. The trial found a statistically significant dose-response relationship (p=0.0185). At 50 mg, the adult dose, total sleep time rose by about 50 minutes from baseline, against about 20 minutes on placebo. In the neurodevelopmental subgroup the figures were 64 and 27 minutes. Caregivers reported an increase of about 69 minutes on 50 mg after two weeks, against about 30 minutes on placebo.
Idorsia said adverse events at 50 mg were similar in incidence to placebo, with no signals of abuse potential, physical dependence or withdrawal.
The limits of the evidence
The data come from a company release, and the full manuscript is still under journal review. The release reports within-group changes rather than placebo-adjusted differences with confidence intervals. Two weeks of treatment in 165 patients says little about long-term safety in a population whose brains are still developing, a caveat that applies with particular force to a drug acting on sleep and wake regulation.
Two weeks of data cannot answer the question that matters most to prescribers: what happens after months of nightly use.
The subgroup figures also need care. A larger increase in sleep time among children with neurodevelopmental disorders does not show that the drug improves the underlying condition.
Why it matters
"Treatment options for children and adolescents with insomnia remain extremely limited," said Katharina Lederer, the study's principal investigator, when the topline results were reported. Controlled trials in this population are unusual, and the paediatric study obligations attached to adult approvals in the US and EU are part of the reason this one exists.
Idorsia says it is consolidating feedback from health authorities on a phase 3 protocol and expects that programme to begin in the second half of 2027. Any paediatric approval is therefore several years away, and will depend on longer trials showing that the first-night effect is sustained.
