Tasimelteon clinical trials
Tasimelteon is named as an intervention in 2 current clinical trials in our UK, USA, Germany, Poland and Turkey registers. 2 are recruiting patients now. All registered phases are Phase 3. The lead sponsor is Vanda Pharmaceuticals. The most-studied condition is Insomnia Disorder.
Where Tasimelteon is approved
All regulators →Of the three regulators tracked here, the first to approve Tasimelteon was the US, on 31 Jan 2014. It is approved in 2 of the 3 regulators tracked here.
- 2 EU orphan designations, most recently for treatment of Smith-Magenis syndrome (13 Oct 2023, positive)
From the regulators' own registers: FDA Drugs@FDA, the EMA medicines list and Health Canada's Notice of Compliance database. Dates are the first listed approval of a product containing only this substance; combination products and nationally authorised EU medicines are not counted.
Tasimelteon patents and exclusivity
Expiry tracker →Protections still running for marketed products containing Tasimelteon, as listed by the regulators. Expired patents and exclusivities, and discontinued products, are not shown.
- 33 listed patents; the last listed expires 21 Feb 2041 (US 11759446).
- Latest patent on the drug substance itself: 12 Feb 2035 (US 11566011).
- Exclusivity ODE-330: Orphan drug exclusivity: the treatment of nighttime sleep disturbances in smith-magenis syndrome (sms) in patients 16 years of age and older, until 1 Dec 2027.
- Exclusivity ODE-329: Orphan drug exclusivity: for the treatment of nighttime sleep disturbances in smith-magenis syndrome (sms) in pediatric patients 3 to 15 ye…, until 1 Dec 2027.
Reproduced from the FDA Orange Book and Purple Book (checked 8 Nov 2026) and the European Commission's Union Register of medicinal products (CC BY 4.0; the EU expiry date is calculated exactly as the Commission's register displays it). Listed patents and dates are as submitted to or published by the regulator and may not reflect litigation, invalidation, settlements, lapsed fees or later extensions. This is not legal advice or a freedom-to-operate opinion, and it does not say when a generic or biosimilar will launch.
What health systems spend on Tasimelteon
All medicines →From NHSBSA Prescription Cost Analysis (Open Government Licence v3.0) and CMS State Drug Utilization Data. Both are gross amounts: neither system publishes its discounts or rebates per drug. Products combining several substances are not counted here.
How Tasimelteon works
All drug targets →- Melatonin receptor agonist AgonistTarget: Melatonin receptor✓ In ChEMBL and the Guide to Pharmacology
- Sleep disturbancePhase 3
- Major depressive disorderPhase 2/3
- Neurodevelopmental disorderPhase 1
- REM sleep behavior disorderEarly phase 1
Mechanisms and diseases from ChEMBL via the Open Targets Platform (release 26.09), ChEMBL record CHEMBL2103822, CC BY-SA 3.0. Targets checked against the IUPHAR/BPS Guide to PHARMACOLOGY (2026.3.1), ligand 7393, CC BY-SA 4.0. Trial phases are not approvals: approved uses are shown from the regulators' own records where we hold them.
Patient leaflets for Tasimelteon
The package leaflet is the official guide for patients that comes with every medicine. These links go to the regulators that publish it.
- IEIreland: 1 product on the HPRA listEach product record links to the HPRA, which publishes the leaflet and SmPC.
- EUEuropean Union: HetliozEMA product information: package leaflet and summary of product characteristics in every EU language.
- UKUnited Kingdom: Search MHRA ProductsPatient information leaflets and SmPCs for UK-licensed products.
- USUnited States: Search DailyMedFDA-approved labels, including patient and medication guides.
Leaflets differ between brands and countries; always read the one that comes with your own medicine. This is regulatory information, not medical advice.
Reference identifiers for Tasimelteon
- ATC code
- N05CH03
- ChEMBL
- CHEMBL2103822
- DrugBank
- DB09071
- PubChem CID
- 10220503
- CAS number
- 609799-22-6
- FDA UNII
- SHS4PU80D9
- Wikidata
- Q7687250
- Wikipedia
- Tasimelteon
Codes that identify this medicine in other databases, from Wikidata (CC0), matched by its ChEMBL ID. The ATC code is the WHO classification of what the medicine is used for.
Trials by status
Trials by phase
Clinical trials of Tasimelteon
2 trials| Study | Phase | Status | Lead sponsor | Registers |
|---|---|---|---|---|
|
Evaluating the Effects of Tasimelteon Vs. Placebo in Delayed Sleep-Wake Phase Disorder (DSWPD) and the CRY1Δ11 Variant
NCT06701396 · ClinicalTrials.gov ↗ · Sleep Wake Disorders, Sleep Disorders, Circadian Rhythm, Chronobiology Disorders
|
Phase 3 | Recruiting | Vanda Pharmaceuticals | Turkey |
|
Evaluating the Effects of Tasimelteon vs. Placebo in Treating Pediatric Insomnia
NCT06953869 · Insomnia Disorder
|
Phase 3 | Recruiting | Vanda Pharmaceuticals | UK, USA, Germany, Poland |
Registers list studies that are recruiting, about to open, active but closed to enrolment, or enrolling by invitation. The UK and USA registers cover industry-sponsored studies only. Trial titles and statuses are copied from the registry as published.
Tasimelteon across our data
Ireland · EU · USThe same active substance in our other registers, matched by its exact name. Each entry links to the register record it comes from.
Licensed in Ireland (HPRA)
1 single-substance product containing Tasimelteon on the HPRA medicines list.
- HETLIOZ 20 mg hard capsulesVanda Pharmaceuticals Netherlands B.V. · EU/1/15/1008/001
Supply shortages
No entry for Tasimelteon in the EMA, FDA or German BfArM shortage lists we track.
Conditions studied with Tasimelteon
5 conditionsSponsors
lead sponsor per trial| Lead sponsor | Trials |
|---|---|
| Vanda Pharmaceuticals | 2 |
By country register
| Register | Trials | Recruiting |
|---|---|---|
| Clinical trials in UK | 1 | 1 |
| Clinical trials in USA | 1 | 1 |
| Clinical trials in Germany | 1 | 1 |
| Clinical trials in Poland | 1 | 1 |
| Clinical trials in Turkey | 1 | 1 |
A trial with sites in more than one country appears in each of those registers.
Related compounds
Questions about Tasimelteon trials
How many clinical trials are testing Tasimelteon?
2 current trials in our UK, USA, Germany, Poland and Turkey registers name Tasimelteon as a drug or biological intervention, as of the registry sync on 11 November 2026. Completed and withdrawn studies are not counted.
Are Tasimelteon trials recruiting patients?
Yes. 2 of the 2 trials are recruiting: 1 with sites in UK, 1 with sites in USA, 1 with sites in Germany, 1 with sites in Poland and 1 with sites in Turkey. Eligibility and site contacts are on each trial's record. Only the study team can confirm whether a patient is eligible.
Who sponsors Tasimelteon clinical trials?
The lead sponsor is Vanda Pharmaceuticals. The number in brackets is how many trials each organisation leads.
Is Tasimelteon licensed in Ireland?
Yes. The HPRA medicines list includes 1 single-substance product containing Tasimelteon, for example HETLIOZ 20 mg hard capsules (Vanda Pharmaceuticals Netherlands B.V.). A licence does not mean a product is currently marketed or reimbursed; see each product's record.
Is there a Tasimelteon shortage?
Not in the lists we track: Tasimelteon has no entry in the EMA, FDA or German BfArM shortage registers as of their latest sync.
Where does this information come from?
Every trial, status, phase and sponsor on this page is copied from public ClinicalTrials.gov records by a daily sync. Nothing here describes how Tasimelteon works or whether it is effective, and it is not medical advice.
How this page is built
Everything on this page is copied from public ClinicalTrials.gov registry records — it is not written from memory, and nothing here describes how Tasimelteon works or whether it is effective. Each trial links to its own record so you can check it yourself.
- ClinicalTrials.gov (U.S. National Library of Medicine) ↗ Trial IDs, titles, intervention names and synonyms, phase, overall status, lead sponsor and conditions for every trial on this page
This page is built automatically: a daily sync job reads the registry records behind our country trial registers, collects every trial that lists Tasimelteon (or a registered synonym) as a drug or biological intervention, and tabulates the registry fields directly. Placebos and generic comparators are excluded. There is no AI drafting and no per-compound editorial pass, and the page has not been clinically reviewed. The “last verified” date above is the timestamp of that sync, not a review date. Our general editorial approach is described in our editorial standards and corrections policy. The ClinicalTrials.gov data on this page was last retrieved on 11 Nov 2026. How every register is built: methodology · fixes we have made: corrections log.