Study of the Safety of HPN (Hyperion)-100 for the Long-Term Treatment of Urea Cycle Disorders (Treat UCD)

This was a one year long-term safety study of HPN-100 in UCD subjects. Subjects were assessed regularly for safety and control of their venous ammonia. Hyperammonemic events were characterized with respect to contributing factors, such as intercurrent illness, diet, and noncompliance with medication. Forty subjects with a diagnosis of UCD who completed Study HPN-100-006 were enrolled. Twenty additional UCD subjects ≥ 6 years of age were enrolled. These subjects included those who did not qualify for HPN-100-006 \[e.g., subjects between the ages of 6-17; subjects with other UCD subtypes or adult subjects who have not taken sodium phenylbutyrate (NaPBA) in the past 6 months, etc.\]. For adult subjects not receiving NaPBA in the past 6 months, subjects must, in the judgment of the investigator, be anticipated to benefit from the addition of a nitrogen-scavenging agent to their current treatment. See the inclusion criteria for examples of clinical evidence of potential benefit. Monthly assessments included safety laboratory tests, amino acid panel, vital signs, electrocardiogram (ECG) monitoring, venous ammonia, and blood and urine metabolites. Adverse events (AEs) and concomitant medications were recorded on an ongoing basis. Study acquired from Horizon in 2024.