Clinical Trials Register

Summary
EudraCT Number:	2025-000181-28
Sponsor's Protocol Code Number:	C614
Clinical Trial Type:	Outside EU/EEA
Date on which this record was first entered in the EudraCT database:	2026-03-23
Trial results

Index
A. PROTOCOL INFORMATION
B. SPONSOR INFORMATION
C. APPLICANT IDENTIFICATION
D. IMP IDENTIFICATION
D.8 INFORMATION ON PLACEBO
E. GENERAL INFORMATION ON THE TRIAL
F. POPULATION OF TRIAL SUBJECTS
G. INVESTIGATOR NETWORKS TO BE INVOLVED IN THE TRIAL
H.4 THIRD COUNTRY IN WHICH THE TRIAL WAS FIRST AUTHORISED

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A. Protocol Information

A.2

EudraCT number

2025-000181-28

A.3

Full title of the trial

An Open-Label Study of DCCR (Diazoxide Choline) Extended-Release Tablets in Patients with Prader-Willi Syndrome (PWS)

A.3.1

Title of the trial for lay people, in easily understood, i.e. non-technical, language

Open-Label Study of DCCR in Patients with Prader-Willi Syndrome

A.3.2

Name or abbreviated title of the trial where available

Open-Label Study of DCCR in Patients with Prader-Willi Syndrome

A.4.1

Sponsor's protocol code number

C614

A.5.2

US NCT (ClinicalTrials.gov registry) number

NCT05701774

A.7

Trial is part of a Paediatric Investigation Plan

Yes

A.8

EMA Decision number of Paediatric Investigation Plan

P/402/2024

B. Sponsor Information
B.Sponsor: 1
B.1.1	Name of Sponsor	Soleno Therapeutics UK LTD
B.1.3.4	Country	United Kingdom
B.3.1 and B.3.2	Status of the sponsor	Commercial
B.4 Source(s) of Monetary or Material Support for the clinical trial:
B.4.1	Name of organisation providing support	Soleno Therapeutics, Inc.
B.4.2	Country	United States
B.5 Contact point designated by the sponsor for further information on the trial
B.5.1	Name of organisation	Soleno Therapeutics UK LTD
B.5.2	Functional name of contact point	Clinical Trial Information
B.5.3	Address:
B.5.3.1	Street Address	Garden Cottage, Badgemore Park, Henly-on-Thames
B.5.3.2	Town/ city	Oxfordshire
B.5.3.3	Post code	RG9 4NR
B.5.3.4	Country	United Kingdom
B.5.4	Telephone number	+441491756023
B.5.6	E-mail	C614ProjectManager@soleno.life

D. IMP Identification
D.IMP: 1
D.1.2 and D.1.3	IMP Role	Test
D.2	Status of the IMP to be used in the clinical trial
D.2.1	IMP to be used in the trial has a marketing authorisation	No
D.2.5	The IMP has been designated in this indication as an orphan drug in the Community	Yes
D.2.5.1	Orphan drug designation number	EU/3/17/1941
D.3 Description of the IMP
D.3.1	Product name	DCCR (Diazoxide Choline) Extended- Release Tablet
D.3.2	Product code	DCCR
D.3.4	Pharmaceutical form	Prolonged-release tablet
D.3.4.1	Specific paediatric formulation	No
D.3.7	Routes of administration for this IMP	Oral use
D.3.8 to D.3.10 IMP Identification Details (Active Substances)
D.3.8	INN - Proposed INN	Diazoxide choline
D.3.9.3	Other descriptive name	Diazoxide choline
D.3.9.4	EV Substance Code	SUB192374
D.3.10	Strength
D.3.10.1	Concentration unit	mg milligram(s)
D.3.10.2	Concentration type	equal
D.3.10.3	Concentration number	25
D.3.8 to D.3.10 IMP Identification Details (Active Substances)
D.3.8	INN - Proposed INN	Diazoxide choline
D.3.9.3	Other descriptive name	Diazoxide choline
D.3.9.4	EV Substance Code	SUB192374
D.3.10	Strength
D.3.10.1	Concentration unit	mg milligram(s)
D.3.10.2	Concentration type	equal
D.3.10.3	Concentration number	75
D.3.8 to D.3.10 IMP Identification Details (Active Substances)
D.3.8	INN - Proposed INN	Diazoxide choline
D.3.9.3	Other descriptive name	Diazoxide choline
D.3.9.4	EV Substance Code	SUB192374
D.3.10	Strength
D.3.10.1	Concentration unit	mg milligram(s)
D.3.10.2	Concentration type	equal
D.3.10.3	Concentration number	150
D.3.11 The IMP contains an:
D.3.11.1	Active substance of chemical origin	Yes
D.3.11.2	Active substance of biological/ biotechnological origin (other than Advanced Therapy IMP (ATIMP)	No
	The IMP is a:
D.3.11.3	Advanced Therapy IMP (ATIMP)	No
D.3.11.3.1	Somatic cell therapy medicinal product	No
D.3.11.3.2	Gene therapy medical product	No
D.3.11.3.3	Tissue Engineered Product	No
D.3.11.3.4	Combination ATIMP (i.e. one involving a medical device)	No
D.3.11.3.5	Committee on Advanced therapies (CAT) has issued a classification for this product	No
D.3.11.4	Combination product that includes a device, but does not involve an Advanced Therapy	No
D.3.11.5	Radiopharmaceutical medicinal product	No
D.3.11.6	Immunological medicinal product (such as vaccine, allergen, immune serum)	No
D.3.11.7	Plasma derived medicinal product	No
D.3.11.8	Extractive medicinal product	No
D.3.11.9	Recombinant medicinal product	No
D.3.11.10	Medicinal product containing genetically modified organisms	No
D.3.11.11	Herbal medicinal product	No
D.3.11.12	Homeopathic medicinal product	No
D.3.11.13	Another type of medicinal product	No

D.8 Information on Placebo

E. General Information on the Trial

E.1 Medical condition or disease under investigation

E.1.1

Medical condition(s) being investigated

Prader-Willi syndrome (PWS)

E.1.1.1

Medical condition in easily understood language

Genetic disorder (Prader-Willi syndrome) causing low muscle tone, poor growth, and delayed development in infants; increased appetite and food-related behaviours usually start later in childhood.

E.1.1.2

Therapeutic area

Diseases [C] - Congenital, Hereditary, and Neonatal Diseases and Abnormalities [C16]

MedDRA Classification

E.1.2 Medical condition or disease under investigation

E.1.2	Version	28.0
E.1.2	Level	PT
E.1.2	Classification code	10036476
E.1.2	Term	Prader-Willi syndrome
E.1.2	System Organ Class	10010331 - Congenital, familial and genetic disorders

E.1.3

Condition being studied is a rare disease

Yes

E.2 Objective of the trial

E.2.1

Main objective of the trial

The primary objective of this study is to monitor long-term safety of DCCR (Diazoxide Choline) Extended-Release Tablets in participants with Prader-Willi syndrome (PWS).

E.2.2

Secondary objectives of the trial

There are no secondary objectives in Study C614. Additional objectives of this study are to monitor the long-term efficacy of DCCR in participants with PWS as assessed by changes in hyperphagia (assessed by the Hyperphagia Questionnaire for Clinical Trials [HQCT]) and changes in other PWS behaviors (Anxiety, Compulsivity, Rigidity/Irritability, Aggression, Disordered Thinking, Depression domains) as assessed by the PWS Profile (PWSP) questionnaire.

E.2.3

Trial contains a sub-study

E.3

Principal inclusion criteria

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.

E.4

Principal exclusion criteria

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.

E.5 End points

E.5.1

Primary end point(s)

The primary outcome measures include: adverse event reports, clinical laboratory assessments (including fasting plasma glucose and blood glucose by glucometer, HbA1c, chemistry panel, liver function tests, hematology panel, urinalysis, and the Columbia Suicide Severity Rating Scale (C-SSRS)).

E.5.1.1

Timepoint(s) of evaluation of this end point

Adverse events, C-SSRS, and blood glucose are evaluated at Weeks 0, 2-6, 13, 26, 52, 78, 104, 130, 156, 182, 208, 234, 260. C-SSRS is also evaluated at Week 262.
Fasting plasma glucose, HbA1c, chemistry panel, liver function tests, hematology panel, and urinalysis are evaluated at Weeks 0, 52, 104, 156, 208, and 260.

E.5.2

Secondary end point(s)

There are no secondary outcome measures in Study C614. Additional outcome measures include: changes in hyperphagia (HQ-CT Total Score) and changes in other PWS behaviours (Anxiety, Compulsivity, Rigidity/Irritability, Aggression, Disordered Thinking, Depression domains) as assessed by the PWSP questionnaire.

E.5.2.1

Timepoint(s) of evaluation of this end point

The HQ-CT and the PWSP are evaluated at weeks 0, 13, 26, and 52 in year 1. During years 2-5 evaluation will occur at weeks 104, 156, 208, and 260.

E.6 and E.7 Scope of the trial

E.6

Scope of the trial

E.6.1

Diagnosis

E.6.2

Prophylaxis

E.6.3

Therapy

Yes

E.6.4

Safety

Yes

E.6.5

Efficacy

Yes

E.6.6

Pharmacokinetic

E.6.7

Pharmacodynamic

E.6.8

Bioequivalence

E.6.9

Dose response

E.6.10

Pharmacogenetic

E.6.11

Pharmacogenomic

E.6.12

Pharmacoeconomic

E.6.13

Others

E.7

Trial type and phase

E.7.1

Human pharmacology (Phase I)

E.7.1.1

First administration to humans

E.7.1.2

Bioequivalence study

E.7.1.3

Other

E.7.1.3.1

Other trial type description

E.7.2

Therapeutic exploratory (Phase II)

E.7.3

Therapeutic confirmatory (Phase III)

Yes

E.7.4

Therapeutic use (Phase IV)

E.8 Design of the trial

E.8.1

Controlled

E.8.1.1

Randomised

E.8.1.2

Open

Yes

E.8.1.3

Single blind

E.8.1.4

Double blind

E.8.1.5

Parallel group

E.8.1.6

Cross over

E.8.1.7

Other

E.8.2

Comparator of controlled trial

E.8.2.1

Other medicinal product(s)

E.8.2.2

Placebo

E.8.2.3

Other

E.8.3

Will this trial be conducted at a single site globally?

E.8.4

Will this trial be conducted at multiple sites globally?

Yes

E.8.6 Trial involving sites outside the EEA

E.8.6.2

Trial being conducted completely outside of the EEA

Yes

E.8.6.3

Specify the countries outside of the EEA in which trial sites are planned

United Kingdom

United States

E.8.7

Trial has a data monitoring committee

E.8.8

Definition of the end of the trial and justification where it is not the last visit of the last subject undergoing the trial

The end of the trial is the completion of the analyses of the final data. Data are considered final when all queries related to the data are resolved, the data are clean, and the database has been locked.

E.8.9 Initial estimate of the duration of the trial

E.8.9.2

In all countries concerned by the trial years

E.8.9.2

In all countries concerned by the trial months

F. Population of Trial Subjects

F.1 Age Range

F.1.1

Trial has subjects under 18

Yes

F.1.1

Number of subjects for this age range:

F.1.1.1

In Utero

F.1.1.2

Preterm newborn infants (up to gestational age < 37 weeks)

F.1.1.3

Newborns (0-27 days)

F.1.1.4

Infants and toddlers (28 days-23 months)

F.1.1.5

Children (2-11years)

Yes

F.1.1.5.1

Number of subjects for this age range:

F.1.1.6

Adolescents (12-17 years)

Yes

F.1.1.6.1

Number of subjects for this age range:

F.1.2

Adults (18-64 years)

Yes

F.1.2.1

Number of subjects for this age range:

F.1.3

Elderly (>=65 years)

F.2 Gender

F.2.1

Female

Yes

F.2.2

Male

Yes

F.3 Group of trial subjects

F.3.1

Healthy volunteers

F.3.2

Patients

Yes

F.3.3

Specific vulnerable populations

Yes

F.3.3.1

Women of childbearing potential not using contraception

F.3.3.2

Women of child-bearing potential using contraception

Yes

F.3.3.3

Pregnant women

F.3.3.4

Nursing women

F.3.3.5

Emergency situation

F.3.3.6

Subjects incapable of giving consent personally

Yes

F.3.3.6.1

Details of subjects incapable of giving consent

Patients with PWS may experience a number of physical and mental incapabilities that result from developmental delays in muscle development and cognition. In terms of mental age, patients with PWS tend to reach the equivalent of age 12-15.

F.3.3.7

Others

F.4 Planned number of subjects to be included

F.4.2

For a multinational trial

F.4.2.2

In the whole clinical trial

F.5

Plans for treatment or care after the subject has ended the participation in the trial (if it is different from the expected normal treatment of that condition)

In the event that DCCR does not become commercially available in the UK after the completion of Study C614 or if the Sponsor terminates the DCCR Development Program for PWS, DCCR may be made available to subjects on a named patient basis or they may continue on their normal pre-study treatment for the condition.

G. Investigator Networks to be involved in the Trial

H.4 Third Country in which the Trial was first authorised
H.4.1	Third Country in which the trial was first authorised:	United States

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