Glut1 DeficiencyPhase 2NCT07432490
A Phase II Study With Exploratory Outcomes of Fucose Supplementation in GLUT1 Deficiency Syndrome
A Phase 2 study testing L-fucose in people with Glut1 Deficiency and GLUT1DS1, run by Oregon Health and Science University at 1 site in United States.
Trial summary
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). Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Glut1 Deficiency, GLUT1DS1
- What is being tested?
- L-fucose
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 16 participants
- Where
- 1 siteUnited States
- Study dates
- 5 May 2026to Aug 2027
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
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 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 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
Who cannot join
- 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
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- 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
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Oregon Health and Science University
Portland, Oregon, 97239
Celena Byerlee-Dixon, MS, CCRP, 971-334-1942, byerlee@ohsu.edu
Rodrigo T. Starosta, MD, PhD
About this study
Official title: A Phase II Randomized, Double-blind, Placebo-controlled, Cross-over Study With Exploratory Outcomes of Fucose Supplementation in GLUT1 Deficiency Syndrome
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).
- Conditions
- Glut1 Deficiency, GLUT1DS1
- Being tested
- L-fucose, Placebo
- Keywords
- GLUT1 Deficiency, GLUT1 Deficiency Syndrome, GLUT1DS, SLC2A1, Fucose, L-fucose
- Medical subject headings
- Glut1 Deficiency Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
L-fucoseDrug
Also called fucose
L-fucose will be administered as 500 mg/kg to a maximum of 10 g three times per day by mouth.
PlaceboOther
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.
| Study group | Role | What they receive |
|---|---|---|
| L-fucose followed by placebo | Active comparator | L-fucose for 12 weeks, followed by placebo for 12 weeks. Receives: Drug: L-fucose; Other: Placebo |
| Placebo followed by L-fucose | Placebo comparator | Placebo for 12 weeks, followed by L-fucose for 12 weeks. Receives: Drug: L-fucose; Other: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
SARA (Scale for the Assessment and Rating of Ataxia) Score
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)
Measured: 24 weeks
Modified SARA (Scale for the Assessment and Rating of Ataxia) score
This modified score suggested by the FDA rates severity of ataxia from 0 (no ataxia) to 16 (most severe ataxia)
Measured: 24 weeks
ICARS (International Cooperative Ataxia Rating Scale) Score
This scale score the severity of ataxia and other cerebellar findings from 0 (no compromise) to 100 (maximal impairment)
Measured: 24 weeks
Safety labs: hemoglobin
Changes in levels of hemoglobin in g/dL
Measured: 24 weeks
Safety labs: white blood cell count
Changes in white blood cell counts as measured in cells/mm3
Measured: 24 weeks
Safety labs: platelet count
Changes in platelet counts measured as cells/mm3
Measured: 24 weeks
Safety labs: lactate dehydrogenase
Changes in lactate dehydrogenase (LDH) levels measured as U/L
Measured: 24 weeks
Safety labs: alanine-aminotransferase
Changes in alanine-aminotransferase (ALT) measured as U/L
Measured: 24 weeks
Safety labs: aspartate-aminotransferase
Changes in aspartate-aminotransferase (AST) measured as U/L
Measured: 24 weeks
Safety labs: gamma-glutamyltransferase
Changes in gamma-glutamyltransferase (GGT) measured as U/L
Measured: 24 weeks
Safety labs: serum creatinine
Changes in serum creatinine measured as mg/dL
Measured: 24 weeks
Safety labs: blood urea nitrogen
Changes in blood urea nitrogen (BUN) measured as mg/dL
Measured: 24 weeks
Safety labs: serum sodium
Changes in serum sodium (Na) as measured in mmol/L
Measured: 24 weeks
Safety labs: serum potassium
Changes in serum potassium (K) measured as mmol/L
Measured: 24 weeks
Safety labs: serum chloride
Changes in serum chloride (Cl) measured as mmol/L
Measured: 24 weeks
Safety labs: serum calcium
Changes in serum calcium (Ca) measured as mmol/L
Measured: 24 weeks
Safety labs: serum bicarbonate
Changes in serum bicarbonate/carbonate measured as mmol/L
Measured: 24 weeks
Subject-reported adverse events
Rate and character (including standardized severity) of adverse events as reported by the study subjects
Measured: 24 weeks
Secondary outcomes (6)
Severity of dysarthria
Number of "PA-TA" repetitions over 10 seconds ("PATA Rate Test")
Measured: 24 weeks
Frequency and severity of migraines
Frequency and severity of migraines captured at a diary for 1 week, at the last week of each study arm.
Measured: 24 weeks
Frequency of paroxysmal exercise-induced dystonia
Frequency of paroxysmal exercise-induced dystonic episodes, captured at a diary for 1 week, at the last week of each study arm.
Measured: 24 weeks
Frequency of seizures
Frequency and duration of seizures captured at a diary for 1 week, at the last week of each study arm.
Measured: 24 weeks
World Health Organization Quality of Life (WHO-QoL) scale
Objective scoring of global and domain-specific quality of life with the World Health Organization Quality of Life (WHO-QoL) scale.
Measured: 24 weeks
Patient-Reported Outcomes Measurement Information System (PROMIS) score
Objective and quantitative measurement of quality of life using the PROMIS Fatigue, Mobility, and Physical Function tool
Measured: 24 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Feb 2026
- Study start5 May 2026
- Primary completionJul 2027 (estimated)
- Study completionAug 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Glut1 DeficiencyStudies of the same condition, open and under way.
- More trials run by Oregon Health and Science UniversityThe sponsor's other registered studies.
- 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 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 16 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Oregon Health and Science University
- Sponsor type
- University, hospital or other
- Collaborators
- Glut1 Deficiency Foundation
- Responsible party
- Principal investigator, Rodrigo Starosta, Oregon Health and Science University
- Investigators
- Rodrigo T. Starosta, MD, PhD, Study director, Oregon Health and Science University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07432490
- Sponsor's protocol ID
- 00028024
- Status last verified
- May 2026
- First submitted
- 14 Feb 2026
- Last updated
- 13 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 13 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase II Randomized, Double-blind, Placebo-controlled, Cross-over Study With Exploratory Outcomes of Fucose Supplementation in GLUT1 Deficiency Syndrome
- ClinicalTrials.gov ID
- NCT07432490
- Acronym / sponsor ID
- 00028024
- Conditions
- Glut1 Deficiency, GLUT1DS1
- Keywords
- GLUT1 Deficiency, GLUT1 Deficiency Syndrome, GLUT1DS, SLC2A1, Fucose, L-fucose
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 16 participants (estimated)
- Lead sponsor
- Oregon Health and Science UniversityUniversity, hospital or other
- Collaborators
- Glut1 Deficiency Foundation
- Study start
- 5 May 2026 (actual)
- Primary completion
- Jul 2027 (estimated)
- Study completion
- Aug 2027 (estimated)
- First posted
- 25 Feb 2026 (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.
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).
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| L-fucose followed by placebo | Active comparator | Drug: L-fucose, Other: PlaceboL-fucose for 12 weeks, followed by placebo for 12 weeks. |
| Placebo followed by L-fucose | Placebo comparator | Drug: L-fucose, Other: PlaceboPlacebo for 12 weeks, followed by L-fucose for 12 weeks. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- 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
Key exclusion criteria (11 listed)
- 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):
- Subjects who are pregnant, breastfeeding, or planning to become pregnant within one year of enrollment
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 |
|---|---|---|
| L-fucoseAlso: fucoseL-fucose will be administered as 500 mg/kg to a maximum of 10 g three times per day by mouth. | Drug | L-fucose followed by placebo, Placebo followed by L-fucose |
| PlaceboPlacebo 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. | Other | L-fucose followed by placebo, Placebo followed by L-fucose |
Primary outcome
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
6 secondary outcomes
Severity of dysarthria
Time frame: 24 weeks
Frequency and severity of migraines
Time frame: 24 weeks
Frequency of paroxysmal exercise-induced dystonia
Time frame: 24 weeks
Frequency of seizures
Time frame: 24 weeks
World Health Organization Quality of Life (WHO-QoL) scale
Time frame: 24 weeks
Patient-Reported Outcomes Measurement Information System (PROMIS) score
Time frame: 24 weeks
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 May 2026.
- Individual participant dataSharing planned: No
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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.
Rodrigo T. Starosta, MD, PhD study director
Oregon Health and Science University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing L-fucose in people with Glut1 Deficiency and GLUT1DS1, run by Oregon Health and Science University at 1 site in United States.
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 3 inclusion and 11 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: looking for participants now, as of the sponsor's last update on 13 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. 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. Some participants in this study may receive a placebo. 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 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Celena Byerlee-Dixon (503-494-7004, byerlee@ohsu.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
SARA (Scale for the Assessment and Rating of Ataxia) Score (time frame: 24 weeks). The study lists 18 primary outcomes in all. 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 May 2026.