Diet Treatment Glucose Transporter Type 1 Deficiency (G1D)

Phase 2

Completed

Conditions: GLUT1DS1
Glucose Transport Defect
Glucose Transporter Type 1 Deficiency Syndrome
Glucose Transporter Protein Type 1 Deficiency Syndrome
Epilepsy
Glucose Metabolism Disorders
Glut1 Deficiency Syndrome 1, Autosomal Recessive

Interventions: Drug: Triheptanoin

Registration Number: NCT03181399

Lead Sponsor: University of Texas Southwestern Medical Center

Brief Summary: Forty-five subjects receiving no dietary therapy with a proven G1D diagnosis will be enrolled. To evaluate the effect of C7 supplementation of a regular diet on a EEG activity in addition to IQ, language, working memory, processing speed, emotional and behavioral functioning, ataxia, and other neuropsychological and neurological performance indices in children and adults genetically diagnosed with G1D receiving a regular diet at enrollment.

Detailed Description: This is an open-label, single arm trial of orally-administered C7 in G1D. Subjects will replace a fixed percentage of their daily caloric intake (based on the results of Protocol 1) with C7 for 6 months, undergo full evaluation and discontinuation of treatment at a 6 month visit, and return for an off-treatment follow up visit 3 months after C7 oil discontinuation, for total duration of participation of 9 months. Subjects will undergo treatment initiation on a 24-hour inpatient basis. During that 24-hr inpatient treatment initiation, subjects will have continuous EEG both to monitor for real-time seizure activity (for safety) and to determine EEG changes (secondary outcome) before, during, and after treatment initiation. Subjects will undergo clinical evaluation, comprehensive blood work, ataxia scale rating, EEG, and neuropsychological testing at baseline, 6 months, and 9 months.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 45

Inclusion Criteria

Diagnosis of glucose transporter type I deficiency (G1D), confirmed by clinical genotyping at a CLIA-certified laboratory or by PET scan.
Stable diet on either a modified atkins diet or on no dietary therapy (i.e., no dietary therapy for 1 month).
Males and females 24 months to 35 years old, inclusive.

Exclusion Criteria

Subjects with evidence of independent, unrelated metabolic and/or genetic disease.
Subjects with a chronic gastrointestinal disorder, such as irritable bowel syndrome, Crohn's disease, or colitis that could increase the subject's risk of developing diarrhea or stomach pain.
Subjects with a BMI (body mass index) greater than or equal to 30.
Subjects currently on dietary therapy (i.e., ketogenic diet, medium chain triglyceride supplemented diets, Atkins diet, low glycemic index diet).
Subjects with no evidence of abnormal EEG (spike wave discharges) in the last 12 months.
Women who are pregnant or breast-feeding may not participate. Women who plan to become pregnant during the course of the study, or who are unwilling to use birth control to prevent pregnancy (including abstinence) may not participate. Females age 10 and over will be asked to provide a urine sample for a pregnancy test via dipstick. Subjects will be asked to agree to abstinence or another form of birth control for the duration of the study.
Allergy/sensitivity to C7.
Previous use of triheptanoin in the past 1 month. Subjects who participate in Protocol 1 of this study are thus eligible.
Subjects exhibiting signs of dementia, or diagnosed with any degenerative brain disorder (such as Alzheimer's disease) that would confound assessment of cognitive changes, in the opinion of the investigator.
Active drug or alcohol use or dependence that, in the opinion of the investigator, would interfere with adherence to study requirements.
Inability or unwillingness of subject or legal guardian/representative to give written informed consent, or assent for children age 10-17.
Addition of a new antiseizure drug in the previous 3 months.

Study & Design

Study Type: INTERVENTIONAL

Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Triheptanoin	Triheptanoin	This is a single arm study.

Primary Outcome Measures

Name	Time	Method
Neuropsychological Score of Sustained Attention	Change after 3 months off treatment	Sustained attention was evaluated using a subtest of Conners' Kiddie Continuous Performance Test Second Edition (K-CPT 2): CPT-Hit Reaction Time Block Change. CPT HRT BC indicates the change in mean response speed as the administration of the test progresses in blocks. A decrease in CPT HRT BC indicates a decrease in reaction time, which means the participant's information processing efficiency increases, and an improvement in sustained attention is noted. The off-treatment period of 3 months was implemented to study whether the impact of treatment persists or goes back to baseline. The number of patients that displayed an increase in CPT HRT BC score (towards baseline) after 3 months off treatment as compared to 6 months on treatment is noted here.
Neuropsychological Score of Working Memory Index Scale (WMI)	Change after 3 months off-treatment	Subjects were administered the Working Memory Index Scale (WMI) from either the Wechsler Primary and Preschool Scale of Intelligence, 4th Edition (WPPSI-IV), Wechsler Intelligence Scale for Children, 5th Edition (WISC-V), or the Wechsler Adult Intelligence Scale, 4th Edition (WAIS-IV) according to the age of subject. An increase WMI score would indicate an improvement in the cognitive ability of identifying, reorganizing and retaining information for a brief period of time. The 3 months off-treatment period was designed to study whether the impact of treatment persists or goes back to baseline. The number of participants that showed a decrease in the WMI score after 3 months off treatment as compared to 6 months on treatment was calculated.
Neuropsychological Score of Processing Speed Index (PSI)	Change after 3 months off-treatment	Subjects were administered the Processing Speed Index Scale (PSI) from either the Wechsler Primary and Preschool Scale of Intelligence, 4th Edition (WPPSI-IV), Wechsler Intelligence Scale for Children, 5th Edition (WISC-V) or the Wechsler Adult Intelligence Scale, 4th Edition (WAIS-IV) according to the age of subject. An increase PSI score would indicate an improvement in the motor-based estimate of the subject's cognitive processing speed. The 3 months off-treatment period was designed to study whether the impact of treatment persists or goes back to baseline. The number of participants that showed a decrease in the WMI score after 3 months off treatment as compared to 6 months on treatment was calculated.

Secondary Outcome Measures

Name	Time	Method
EEG Changes: Generalized Spike Wave Activity and Burst	Change after 3 months off-treatment	The number of generalized spike wave (GSW) activity and bursts were extracted from the patient EEGs. GSW and bursts per hour was calculated. A decrease in the spike wave and burst indicated an improvement. The off-treatment period of 3 months was implemented to study whether the impact of treatment persists or goes back to baseline. The number of patients that displayed an increase in GSW and burst per hour (towards baseline) after 3 months off treatment as compared to 6 months on treatment is noted here.
Brief Ataxia Rating Scale	Change after 3 months off treatment	Ataxia is scored as per the Brief ataxia rating scale (BARS) - a modified form of the International Cooperative Ataxia Rating Scale (ICARS). The possible range for the scores is from 0 (normal, no ataxia) to 30 (severe ataxia). A decrease in the BARS score indicates an improvement in the ataxia symptoms. The off-treatment period of 3 months was implemented to study whether the impact of treatment persists or goes back to baseline. The number of participants that showed a subsequent increase in BARS score (towards baseline) after the of 3 months of no treatment as compared to 6 months on treatment are recorded here.
Clinical Global Impression Severity Scale	Change after 3 months off-treatment	The Clinical global impression - Severity (CGI-S) scale is used to evaluate the illness severity where the scores range from 1 (very much improved) through to 7 (very much worse). A decrease in the CGI-S score indicates a decrease in illness severity. The off-treatment period of 3 months was designed to study whether the impact of treatment persists or goes back to baseline. The number of participants that showed an increase in CGI-S score (towards baseline) after 3 months off treatment as compared to 6 months on treatment is reported