Dose-Escalation Safety Study of HPN-100 to Treat Urea Cycle Disorders
The purpose of this study is to determine whether HPN-100 is safe and tolerable in subjects with Urea Cycle Disorders.
|Study Design:||Endpoint Classification: Safety Study
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Treatment
|Official Title:||A Phase 2, Open-Label, Switch-Over, Dose-Escalation Study of the Safety and Tolerability of HPN-100 Compared to Buphenyl® (Sodium Phenylbutyrate) in Patients With Urea Cycle Disorders|
- Venous Ammonia Levels at the Peak and Mean TNUAC Time-normalized Area Under the Curve) [ Time Frame: At steady state (1 week) on each medication (Buphenyl® alone, HPN-100 alone), and at steady state (1 week) after each dose escalation ] [ Designated as safety issue: No ]Data were collected at pre-first dose and at 30 minutes and 1, 2, 4, 5, 6, 8, 10, 12, and 24 hours post first dose.
- Number of Subjects Experienced Adverse Events [ Time Frame: during the period on 100% Buphenyl (up to 4 weeks) or HPN-100 (up to 10 weeks) ] [ Designated as safety issue: Yes ]
- Number of Subjects Experienced Serious Adverse Events [ Time Frame: during the period subjects on 100% Buphenyl (up to 4 weeks) or HPN-100 (up to 10 weeks) ] [ Designated as safety issue: Yes ]
- Pharmacokinetics (Plasma and Urine PK Parameters of Study Drugs and Their Metabolites) [ Time Frame: At steady state (1 week) on each medication (Buphenyl® alone, HPN-100 alone) ] [ Designated as safety issue: No ]measured AUC0-24 (Area under the curve from time 0 (pre-dose) to 24 hours) for each metabolite in plasma. Data were collected at 30 minutes and 1, 2, 4, 5, 6, 8, 10, 12, and 24 hours post-first dose.
- Drug Preference for HPN-100 or Buphenyl® (as Assessed by Global Preference Question) [ Time Frame: End of Study ] [ Designated as safety issue: No ]
|Study Start Date:||October 2007|
|Study Completion Date:||December 2008|
|Primary Completion Date:||July 2008 (Final data collection date for primary outcome measure)|
Active Comparator: BUPHENYL® to HPN-100 vs. HPN-100
Buphenyl treatment for one week was followed by dose escalation to HPN-100. Dose of Buphenyl was gradually decreased while HPN-100 dose was gradually increased until subject reached dosing of 100% HPN-100. HPN-100 at 100% of the dose was given for 1 week before subject was switched back to original Buphenyl treatment.
Subjects will be taking prescribed dose of Buphenyl® TID (not to exceed 20g/day) at least two weeks prior to enrollment. Subjects will take prescribed dose of Buphenyl® TID for first week of study, and then switch over to HPN-100 TID during a dose-escalation phase. The dose of HPN-100 will be increased and the dose of Buphenyl® will be decreased each week by 50 mg/kg until entire daily dose of phenylbutyrate is HPN-100. Target HPN-100 dose will contain the same amount of phenylbutyrate as the subject's prescribed daily dose of Buphenyl®. Subject will take HPN-100 alone for one week and then switch back to previous dose of Buphenyl for the last week of the study.Drug: BUPHENYL®
BUPHENYL® (sodium phenylbutyrate) tablets and powder have been approved for marketing in the United States since 1996 as an adjunctive therapy in the long-term management of patients with UCDs involving deficiencies of CPS, OTC, or ASS.
When protein is broken down in the body, nitrogen is formed. In healthy individuals, the body combines this nitrogen with other molecules to create a harmless substance called urea, which is excreted in the urine. Patients with Urea Cycle Disorders (UCD) are unable to create as much urea from nitrogen, and therefore, toxic levels of nitrogen can accumulate in the body, causing harm. To treat these patients, doctors usually have the patient consume less protein and supplement certain amino acids that may be lacking. A drug called Buphenyl® is sometimes prescribed as an adjunctive treatment for the chronic maintenance of UCD patients in order to keep ammonia levels down. Some issues with Buphenyl® include a high pill burden (up to 40 pills per day), bad taste and odor, and high sodium content. Like Buphenyl®, HPN-100 provides an alternate way for the body to dispose of nitrogen, other than through the urea cycle. Unlike Buphenyl®, HPN-100 is an odorless, tasteless, concentrated oil that does not contain large amounts of sodium.
Please refer to this study by its ClinicalTrials.gov identifier: NCT00551200
|United States, Minnesota|
|University of Minnesota|
|Minneapolis, Minnesota, United States, 55455|
|United States, Texas|
|Baylor College of Medicine|
|Houston, Texas, United States, 77030|
|Study Director:||Bruce Scharschmidt, MD||Hyperion Therapeutics, Inc.|