Prader-Willi SyndromePhase 3NCT05701774
Open-Label Extension Study of DCCR in Patients With Prader-Willi Syndrome
A Phase 3 study testing DCCR in people with Prader-Willi Syndrome, run by Soleno Therapeutics, Inc. at 22 sites in 2 countries.
Trial summary
The purpose of this is study is to evaluate the long-term safety of DCCR (diazoxide choline) extended-release tablets) in patients with Prader-Willi syndrome. Read more about this study
- Who is it for?
- Ages 4 years and older
- Conditions the study is for
- Prader-Willi Syndrome
- What is being tested?
- DCCR
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 77 participants
- Where
- 22 sitesin 2 countries
- Study dates
- 31 Jan 2023to 29 Apr 2026
- Phase
- Phase 3
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 4 years and older
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Who may be able to join
- Provide voluntary, written informed consent (parent(s) / legal guardian(s) of patient); provide voluntary, written assent (subjects, as appropriate)
- Participant must:
- Have participated in and completed the Study C602 Randomized Withdrawal (RW) Period;
- Have participated in but discontinued from the Study C602 RW Period and at least 16 weeks have elapsed since the date of their randomization into the C602 RW Period; or
- Have participated in Study C602 OLE period, did not consent to participate in the RW Period, and at least 16 weeks have elapsed since the date of their C602 Open-Label Extension End of Treatment Visit.
Who cannot join
- Positive urine pregnancy test (in females of child-bearing potential)
- Females who are pregnant or breastfeeding, and/or plan to become pregnant or to breast-feed during or within 30 days after study participation.
- Participation in a clinical study of an investigational drug (including approved drugs for unapproved uses), investigational device, or therapeutic intervention subsequent to the C602 Open-Label Extension End of Treatment Visit.
Trial locations and contacts
22 sites in 2 countries.
22 sites in 2 countries
United States17 sites
Soleno Clinical Site
Atlanta, Georgia, 30329
Soleno Clinical Site
Bethesda, Maryland, 20892
Soleno Clinical Site
Boston, Massachusetts, 02115
Soleno Clinical Site
Columbus, Ohio, 43205
Soleno Clinical Site
Dallas, Texas, 75231
Soleno Clinical Site
Gainesville, Florida, 32608
Soleno Clinical Site
Indianapolis, Indiana, 46202
Soleno Clinical Site
Lansing, Michigan, 48912
Soleno Clinical Site
Mineola, New York, 11501
Soleno Clinical Site
Nashville, Tennessee, 37212
Soleno Clinical Site
Orange, California, 92868
Soleno Clinical Site
Palo Alto, California, 94304
Soleno Clinical Site
Paterson, New Jersey, 07503
Soleno Clinical Site
Saint Paul, Minnesota, 55102
Soleno Clinical Site
Salt Lake City, Utah, 84112
Soleno Clinical Site
San Diego, California, 92123
Soleno Clinical Site
Seattle, Washington, 98105
United Kingdom5 sites
Fulbourn Hospital
Cambridge, CB21 5EF
Soleno Clinical Site
Glasgow, G51 4TF
Soleno Clinical Site
Hull, HU3 2JZ
Soleno Clinical Site
London, E1 1BB
Soleno Clinical Site
London, SW10 9NH
About this study
Official title: An Open-Label Study of DCCR (Diazoxide Choline) Extended-Release Tablets in Patients With Prader-Willi Syndrome
The purpose of this is study is to evaluate the long-term safety of DCCR (diazoxide choline) extended-release tablets) in patients with Prader-Willi syndrome.
- Conditions
- Prader-Willi Syndrome
- Being tested
- DCCR
- Medical subject headings
- Prader-Willi Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
DCCRDrug
Once daily oral administration
| Study group | Role | What they receive |
|---|---|---|
| DCCR | Experimental | 75 - 525 mg DCCR Receives: Drug: DCCR |
What is being measured
The primary outcome is the main question the study is designed to answer.
Safety of DCCR (adverse events. Safety analyses will be conducted in all subjects who receive at least one dose of DCCR in the C614 study. ( Adverse events)
Assess the safety of DCCR by evaluating the incidence and severity of adverse events.
Safety analyses will be conducted in all subjects who receive at least one dose of DCCR in the C614 study. Adverse events will be described by type and level of severity.
Measured: Baseline to End of Study or until resolution of certain adverse events
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted27 Jan 2023
- Study start31 Jan 2023
- Primary completion12 Jan 2026
- Study completion29 Apr 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Prader-Willi SyndromeStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 3
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 77 participants (actual)
Sponsor and investigators
- Lead sponsor
- Soleno Therapeutics, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05701774
- Sponsor's protocol ID
- C614
- Other IDs
- 2025-000181-28, 2025
- Status last verified
- Oct 2026
- First submitted
- 18 Jan 2023
- Last updated
- 13 Oct 2026
- Results posted
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 13 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- An Open-Label Study of DCCR (Diazoxide Choline) Extended-Release Tablets in Patients With Prader-Willi Syndrome
- ClinicalTrials.gov ID
- NCT05701774
- Acronym / sponsor ID
- C614
- Conditions
- Prader-Willi Syndrome
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 77 participants (actual)
- Lead sponsor
- Soleno Therapeutics, Inc.Industry (pharma, biotech, devices)
- Study start
- 31 Jan 2023 (actual)
- Primary completion
- 12 Jan 2026 (actual)
- Study completion
- 29 Apr 2026 (actual)
- First posted
- 27 Jan 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this is study is to evaluate the long-term safety of DCCR (diazoxide choline) extended-release tablets) in patients with Prader-Willi syndrome.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| DCCR | Experimental | Drug: DCCR75 - 525 mg DCCR |
Who may qualify
- Ages
- 4 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (5 listed)
- Provide voluntary, written informed consent (parent(s) / legal guardian(s) of patient); provide voluntary, written assent (subjects, as appropriate)
- Participant must:
Key exclusion criteria (3 listed)
- Positive urine pregnancy test (in females of child-bearing potential)
- Females who are pregnant or breastfeeding, and/or plan to become pregnant or to breast-feed during or within 30 days after study participation.
- Participation in a clinical study of an investigational drug (including approved drugs for unapproved uses), investigational device, or therapeutic intervention subsequent to the C602 Open-Label Extension End of Treatment Visit.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| DCCROnce daily oral administration | Drug | DCCR |
Primary outcome
Safety of DCCR (adverse events. Safety analyses will be conducted in all subjects who receive at least one dose of DCCR in the C614 study. ( Adverse events)
Time frame: Baseline to End of Study or until resolution of certain adverse events
Assess the safety of DCCR by evaluating the incidence and severity of adverse events. Safety analyses will be conducted in all subjects who receive at least one dose of DCCR in the C614 study. Adverse events will be described by type and level of severity.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 Oct 2026.
Related trials for Prader-Willi Syndrome
RecruitingPhase 2
A Study of CSTI-500 in Patients With Prader-Willi Syndrome
Prader-Willi Syndrome
Recruiting
Cerebellar TMS and Satiety in Prader-Willi Syndrome
Prader-Willi Syndrome
Enrolling by invitationObservational study
Observational Study of VYKAT™ XR in Patients With Prader-Willi Syndrome
Prader-Willi Syndrome
Active, not recruitingPhase 1/2
A Study of RM-718 in Healthy Subjects and Patients With MC4R Pathway Impairment
Hypothalamic Obesity, Prader-Willi Syndrome
Active, not recruiting
Impact of Bright Light Therapy on Prader-Willi Syndrome
Prader-Willi Syndrome, Excessive Daytime Sleepiness
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
22 sites in 2 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing DCCR in people with Prader-Willi Syndrome, run by Soleno Therapeutics, Inc. at 22 sites in 2 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 13 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 22 sites in United States, United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Safety of DCCR (adverse events. Safety analyses will be conducted in all subjects who receive at least one dose of DCCR in the C614 study. ( Adverse events) (time frame: Baseline to End of Study or until resolution of certain adverse events). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 13 Oct 2026.