NCT06018519: CREAT_criteria

Relevant Outcome Measures for Creatine Transporter Deficiency Patient

Recruiting now NA Last updated 2 December 2025

What this trial tests

NA trial testing Clinical endpoints in Creatine Transporter Defect in 197 participants. Currently enrolling.

Timeline

13 March 2023

Primary endpoint
13 December 2026

13 December 2026

Quick facts

Lead sponsor	Hospices Civils de Lyon
Phase	NA
Status	Recruiting now
Study type	INTERVENTIONAL
Allocation	non randomized
Design	parallel
Masking	none
Primary purpose	other
Enrollment	197
Start date	13 March 2023
Primary completion	13 December 2026
Estimated completion	13 December 2026
Sites	1 location across France

Drugs / interventions tested

• Clinical endpoints
• Parental questionnaires
• Quality of life scale
• Cognitive assessments
• Language assessments
• Motor assessments
• Social assessments
• 3T MRI
• Cardiac assessments
• Biological collection — full drug profile →

Conditions studied

• Creatine Transporter Defect — all drugs for Creatine Transporter Defect →

Sponsor

Hospices Civils de Lyon — full company profile →

Who can join

Adults 2 to 60, any sex, with Creatine Transporter Defect. Patients with the condition only — healthy volunteers not accepted.

Sponsor's own description

Creatine transport deficiency (CTD) is a rare genetic disorder related to pathogenic variants in the SLC6A8 gene, located on chromosome Xq28. Clinical diagnosis of CTD is based on clinical presentation, an increased urinary creatine/creatinine ratio and a severe decreased creatine peak on 1H-MRS magnetic resonance spectroscopy.

A retrospective study with questionnaires identified that most CTD patients had moderate to severe intellectual disability. Less than one third of patients were able to speak in sentences. Seizures were present in 59% of the patients. 41% had autistic features. Motor dysfunction was mentioned in 58%, and gastrointestinal symptoms were reported in 35% of the patients.

Several new therapeutic avenues are currently emerging in this disease for which no treatment has been available until now : cyclocreatine (interesting but unfortunately with very little clinical applicability due to its toxicity; dodecyl creatine ester incorporated into lipid nanocapsules with intranasal administration; pharmaco-chaperoning (for the folding-deficient creatine transporter variants, Ultragenyx pharmaceuticals new prodrug designed to deliver creatine to the brain (UX068). These new pharmacological treatment options may offer future opportunities to improve cognition in CTD patients.

A key issue is to determine outcome measures that are accessible to these patients, despite the importance of their cognitive deficit. In a preliminary study (on 31 CTD patients), investigators showed for example, that 75% of patients were unable to perform a Wechsler scale, which is one of the most used neuropsychological test to determine patient IQ (intelligence quotient). Most of the existing cognitive tests were developed to distinguish typically developing persons and ID (intellectual disability) patients, leading to a floor effect in the latter who systematically fail these tests. Therefore, these tests are not adapted to capture the potential effect of a drug in ID patient group. The identification of reliable and sensitive outcome measures for use in clinical trials in ID patients was recognized as a priority in a meeting convened by the NIH. N-of-1 trials (also called Single-Case Experimental Designs or SCEDs) appear of great interest for rare diseases, statistical power coming from the number of repeated measures, which leads to choose outcome measures that can be repeated multiple times.

This innovative study will allow to efficiently preparing future therapeutic trials, by specifying the phenotype of the patients, and by determining the most adapted outcome measures taking into account their cognitive deficiency and the type of experimental design to be used in the context of rare diseases.

Publications & conference data

No peer-reviewed publications indexed yet for this trial.