Conditions: Urea Cycle Disorders
Keywords: Urea Cycle Disorder UCD GT4P Buphenyl hyperammonemia sodium phenylbutyrate
Allocation: NA | Intervention model: SINGLE_GROUP
Enrollment: 23
Healthy volunteers: no

Brief summary:
This non-randomized, open-label study was approximately one year in duration and consisted of a short term NaPBA to HPN-100 switchover part involving two overnight stays followed by a 12-month long term treatment period involving monthly visits.

Detailed description:
This was an open-label study consisting of a 10-day switch-over period during which subjects were switched from their prescribed dose of sodium phenylbutyrate (BUPHENYLTM or NaPBA) to a dose of HPN-100 that delivered the same amount of the active ingredient, PBA, followed by long-term treatment with HPN-100 for up to 12 months. The study was designed to capture information important for evaluating safety, Pharmacokinetics, and efficacy while recognizing sampling limitations in young children and current standard of care. Patients eligible for this study included pediatric patients from 29 days to \< 6 years of age with either a diagnosed or clinically suspected Urea Cycle Disorders (UCD) who are receiving a stable dose of the powder formulation of NaPBA. Subjects were clinically stable and had been receiving a stable dose NaPBA powder for at least 5 days at the time of enrollment.

During the switch-over part of the study, subjects switched from NaPBA to HPN-100 in one step and had two overnight stays with 24 hour blood sampling, the first of which was on Day 1, while still taking NaPBA, and the second of which was on approximately Day 10 while taking HPN-100. Subjects then continued in the long-term treatment phase which was 12 months in duration.

Study acquired from Horizon in 2024.

Arms:
arm 1: Switch over from sodium phenylbutyrate to open label HPN-100 oral liquid over 10 days then open label, long term treatment for 12 months

Interventions: intervention 1: HPN-100
Intervention descriptions: intervention 1: HPN-100 is a pro-drug of PAA that combines with glutamine to provide an alternative vehicle for waste nitrogen elimination. It is a liquid with minimal taste and odor. Approximately three teaspoons of HPN-100 (\~17.4 mL) delivers an equivalent amount as PBA that 40 tablets of NaPBA.

Protocol document: