NCT07432490 · Oregon Health and Science University
A Phase II Study With Exploratory Outcomes of Fucose Supplementation in GLUT1 Deficiency Syndrome
What this study is about
This is a single-center, randomly assigned, where neither patients nor doctors know which treatment is given, compared against an inactive treatment, cross-over study to evaluate the effectiveness and safety of L-fucose supplementation in subjects with GLUT1 deficiency syndrome (GLUT1DS).
View original scientific description
This is a single-center, randomized, double-blind, placebo-controlled, cross-over study to evaluate the efficacy and safety of L-fucose supplementation in subjects with GLUT1 deficiency syndrome (GLUT1DS).
Interventions
DRUG
L-fucose
L-fucose will be administered as 500 mg/kg to a maximum of 10 g three times per day by mouth.
OTHER
Placebo
Placebo will be composed of micro-cellulose powder with a small amount of Stevia for taste mimicking, to be taken at 500 mg/kg for a maximum of 10 g three times per day by mouth.
Primary outcome measures
SARA (Scale for the Assessment and Rating of Ataxia) Score
Time frame: 24 weeks
Severity of ataxia and cerebellar involvement as measured by the SARA clinical scales. This score ranges from 0 (no ataxia) to 40 (most severe ataxia)
Modified SARA (Scale for the Assessment and Rating of Ataxia) score
Time frame: 24 weeks
This modified score suggested by the FDA rates severity of ataxia from 0 (no ataxia) to 16 (most severe ataxia)
ICARS (International Cooperative Ataxia Rating Scale) Score
Time frame: 24 weeks
This scale score the severity of ataxia and other cerebellar findings from 0 (no compromise) to 100 (maximal impairment)
Safety labs: hemoglobin
Time frame: 24 weeks
Changes in levels of hemoglobin in g/dL
Safety labs: white blood cell count
Time frame: 24 weeks
Changes in white blood cell counts as measured in cells/mm3
Safety labs: platelet count
Time frame: 24 weeks
Changes in platelet counts measured as cells/mm3
Safety labs: lactate dehydrogenase
Time frame: 24 weeks
Changes in lactate dehydrogenase (LDH) levels measured as U/L
Safety labs: alanine-aminotransferase
Time frame: 24 weeks
Changes in alanine-aminotransferase (ALT) measured as U/L
Safety labs: aspartate-aminotransferase
Time frame: 24 weeks
Changes in aspartate-aminotransferase (AST) measured as U/L
Safety labs: gamma-glutamyltransferase
Time frame: 24 weeks
Changes in gamma-glutamyltransferase (GGT) measured as U/L
Safety labs: serum creatinine
Time frame: 24 weeks
Changes in serum creatinine measured as mg/dL
Safety labs: blood urea nitrogen
Time frame: 24 weeks
Changes in blood urea nitrogen (BUN) measured as mg/dL
Safety labs: serum sodium
Time frame: 24 weeks
Changes in serum sodium (Na) as measured in mmol/L
Safety labs: serum potassium
Time frame: 24 weeks
Changes in serum potassium (K) measured as mmol/L
Safety labs: serum chloride
Time frame: 24 weeks
Changes in serum chloride (Cl) measured as mmol/L
Safety labs: serum calcium
Time frame: 24 weeks
Changes in serum calcium (Ca) measured as mmol/L
Safety labs: serum bicarbonate
Time frame: 24 weeks
Changes in serum bicarbonate/carbonate measured as mmol/L
Subject-reported adverse events
Time frame: 24 weeks
Rate and character (including standardized severity) of adverse events as reported by the study subjects
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Age ≥ 18 years
- Confirmed diagnosis of GLUT1DS, including at least 2 out of the following 3: molecular genetic testing showing a pathogenic or likely pathogenic variant in SLC2A1; documented hypoglycorrhachia with a CSF:blood glucose ratio ≤ 0.6; clinical features consistent with GLUT1DS (epilepsy, movement disorders, ataxia, intellectual disability, dysarthria)
- Presence of ataxia
Exclusion criteria
- Inability to swallow liquids
- Change in neurological medications (either medication itself or medication dosages) in the past 90 days
- Use of fucose- or mannose-containing supplements within one year of enrollment
- Presence of hepatic, renal, hematological, or concomitant metabolic disorders, as assessed by the presence of a previous diagnosis of such disorders (for instance, chronic kidney disease, liver cirrhosis, diabetes mellitus) or by the following laboratory values, which will be considered if obtained clinically up to 90 days before enrollment (if this is not available, laboratory tests will be obtained prior to first study visit):
- Any degree of hepatic impairment based on the Child-Pugh classification
- eGFR (as measured by serum creatinine or cystatin C) \< 60 mg/min/1.73m2
- Hemoglobin A1c \> 6.5%
- Hemoglobin level below the lower limit of normal (LLN) for sex and age
- Platelet counts below the LLN for sex and age
- Subjects who are pregnant, breastfeeding, or planning to become pregnant within one year of enrollment
- Enrollment in an investigational new drug trial for G1DS within one year of enrollment
Where
- Portland, Oregon
Collaborators
Glut1 Deficiency Foundation
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced May 13, 2026 · Source of record for eligibility and locations