Study to Assess the Long Term Safety and Efficacy of UX007 in Subjects With Glucose Type 1 DS

A Phase 2 study (UX007G-CL-201) is currently ongoing to assess safety and efficacy of UX007
in reducing the frequency of seizures in Glut 1 DS patients. ISTs and other treatment
programs are also evaluating UX007 as a treatment for Glut 1 DS.

This open label long term safety and efficacy study (UX007G-CL202) will provide an
opportunity for Glut 1 DS patients to be treated with UX007 for up to 3 years (or until
market approval) under a single standardized protocol for maintenance therapy and consistent
safety monitoring. The study is designed to obtain long-term safety information and evaluate
maintenance of efficacy in a pediatric and adult Glut 1 DS population.

Inclusion Criteria:

- Diagnosis of Glut 1 DS confirmed by cerebrospinal fluid glucose concentration.
erythrocyte 3-O-methyl-D-glucose uptake assay, or SLC2A1 molecular genetic testing
(Information obtained from Medical Records)

- Males and females aged at least 1 year old at the time of informed consent

- Completion of UX007G-CL201 study (NCT - 01993186). Glut1 DS patients who received
UX007/triheptanoin treatment as apart of clinical studies, ISTs or expanded
access/compassionate use treatment programs may be eligible at the discretion of the
Sponsor

- Provide written informed consent or verbal assent (if possible) with written informed
consent by a legally authorized representative after the nature of the study has been
explained, and prior to any research related procedures

- Must, in the opinion of the investigator, be willing and able to complete all aspects
of the study, and comply with accurate completion of the seizure diary

- Females of childbearing potential must have a negative urine pregnancy test at
Baseline and be willing to have additional pregnancy tests during the study. Females
considered not of childbearing potential include those who have not experienced
menarche, are post-menopausal (defined as having no mensus for at least 12 months
without an alternative medical cause), or are permanently sterile due to total
hysterectomy, bilateral salpingectomy, or bilateral oophorectomy.

- Participants of child-bearing potential or fertile males with partners of
child-bearing potential who are sexually active must consent to use a highly-effective
method of contraception as determined by the investigator from the period following
the signing of the informed consent through 30 days after last dose of study drug.

Exclusion Criteria:

- Any known hypersensitivity to triheptanoin, that in the judgement of the investigator,
places the subject at an increased risk for adverse effects

- History of, or current suicidal ideation, behavior and/or attempts

- Pregnant and/or breast feeding an infant

- Unwilling or unable to discontinue use of prohibited medication (barbiturates,
pancreatic lipase inhibitors) or other substance that may confound study objectives.
Use of up to 3 concomitant AEDs is allowed, provided dose has been stable at least 14
days prior to Baseline

- Use of any Investigational Product, drug or supplement (other than UX007) within 30
days prior to Baseline, or at any time during the study

- Has a condition of such severity and acuity, in the opinion of the investigator, that
it warrants immediate surgical intervention or other treatment

- Has a concurrent disease or condition, or laboratory abnormality that, in the view of
the investigator, places the subject at high risk of poor treatment compliance or of
not completing the study, or would interfere with study participation or introduce
additional safety concerns