At a glance
| Known as | cleminorexton · ORX750 |
|---|---|
| Sponsor | Centessa Pharmaceuticals — a wholly owned subsidiary of Eli Lilly since 24 Jun 2026 |
| Mechanism | Oral orexin receptor 2 (OX2R) agonist |
| Stage | Phase 3 |
| Indications | NT1 · NT2 · IH |
| Registered trials | 3 · 3 recruiting |
| Last verified | 4 Aug 2026 |
Where it stands
Cleminorexton is the orexin programme that changed hands. Eli Lilly completed its acquisition of Centessa Pharmaceuticals on 24 June 2026, making the company a wholly owned subsidiary and putting this compound inside one of the largest pharmaceutical organisations in the world.
A registrational Phase 2/3 study opened on 29 May 2026 and plans to randomise 222 participants with narcolepsy type 1 or type 2 against placebo. The earlier Phase 2 programme continues as a long-term extension covering all three conditions the drug is aimed at: NT1, NT2 and idiopathic hypersomnia.
The Phase 2a data behind it covered 55 participants and was the first demonstration of an oral OX2R agonist working across NT1, NT2 and IH together — a broader signal than any single-indication result.
Phase 2a data on 55 participants was the first showing of an oral OX2R agonist working across NT1, NT2 and IH.
Registered trials
All 3 studies on ClinicalTrials.gov that name cleminorexton or its development code, pulled from the registry on 4 Aug 2026.
| Registry ID | Study | Phase | Status | Primary completion |
|---|---|---|---|---|
NCT07598708 |
A Study to Investigate the Effects of Cleminorexton Compared With Placebo in the Treatment of Participants With Central Disorders of HypersomnolenceRegistrational study. 222 participants with NT1 or NT2, randomised against placebo. Opened 29 May 2026.222 participants | Phase 2/Phase 3 | Recruiting | 30 Sept 2027 |
NCT07096674 |
A Long-term Extension Study of ORX750 in Participants With Narcolepsy and Idiopathic HypersomniaLong-term extension of the earlier Phase 2 programme, covering NT1, NT2 and idiopathic hypersomnia.90 participants | Phase 2 | Recruiting | 30 Apr 2026 |
NCT06752668 |
A Study of ORX750 in Participants With Narcolepsy and Idiopathic Hypersomnia248 participants | Phase 2 | Recruiting | 1 Dec 2026 |
Trial records are maintained by the sponsor and change without notice. Follow each link for current recruitment status and eligibility.
cleminorexton — common questions
Who owns cleminorexton?
Eli Lilly. It was developed by Centessa Pharmaceuticals, which Eli Lilly acquired outright on 24 June 2026. Centessa now operates as a wholly owned Lilly subsidiary.
What conditions is cleminorexton being tested in?
Narcolepsy type 1, narcolepsy type 2 and idiopathic hypersomnia. The registrational Phase 2/3 study covers NT1 and NT2; the long-term extension covers all three.
What is ORX750?
ORX750 is the development code for cleminorexton, the Centessa compound now owned by Eli Lilly.
How many people are in the cleminorexton registrational trial?
222 participants with narcolepsy type 1 or type 2, randomised against placebo. The study, NCT07598708, opened on 29 May 2026.
Source
This entry was last checked against its primary source on 4 Aug 2026: https://clinicaltrials.gov/study/NCT07598708
Found something out of date? Send a correction with a primary source and it will be fixed.
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