Study of the Efficacy and Safety of HPN-100, Glyceryl Tri-(4-phenylbutyrate), for the Treatment of Adults With Urea Cycle Disorders (Help UCD)

This study has been completed.
Sponsor:
Information provided by (Responsible Party):
Hyperion Therapeutics, Inc.
ClinicalTrials.gov Identifier:
NCT00992459
First received: October 8, 2009
Last updated: July 10, 2013
Last verified: July 2013
  Purpose

This was a randomized, active-controlled, double-blind, cross-over study designed to enroll subjects with UCDs who are being treated with NaPBA. Subjects were randomly assigned to receive either HPN-100 + NaPBA placebo or NaPBA + HPN 100 placebo for 2 weeks, and then crossed over to receive the other treatment for 2 weeks. Venous ammonia was the primary outcome measure. Subjects were admitted to the clinical research unit for 24 hours of pharmacokinetic (PK) blood and urine sampling (including an overnight stay) at the end of each treatment period, by which time the study drug had reached steady state. Please see Appendix B for the timing of ammonia sampling.

Subjects followed a stable diet throughout the study as prescribed by the investigator and dietician. Throughout the study, diet diaries were completed by the subject and dietary protein intake were assessed by a dietician based on completed dietary diaries and consultation with the subject.

Subjects who completed this study and met the study entry criteria, were be offered the opportunity to enroll in the HPN-100 open-label safety protocol (HPN-100-007).


Condition Intervention Phase
Urea Cycle Disorders
Drug: HPN-100
Drug: Buphenyl (NaPBA)
Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Crossover Assignment
Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: A Phase 3, Randomized, Double-Blind, Cross-Over, Active-Controlled Study of the Efficacy and Safety of HPN-100, Glyceryl Tri-(4-phenylbutyrate), for the Treatment of Adults With Urea Cycle Disorders (Help UCD)

Resource links provided by NLM:


Further study details as provided by Hyperion Therapeutics, Inc.:

Primary Outcome Measures:
  • The Primary Endpoint Was the 24-hour Area Under the Curve for Blood Ammonia (NH324-hour AUC) on Days 14 and 28. [ Time Frame: pre-dose, 2, 4, 8, 12, 16, 20 and 24 hours after first dose on days 14 and 28 ] [ Designated as safety issue: No ]
    Blood samples were collected at pre-dose, 2, 4, 8, 12, 16, 20 and 24 hours after first dose on days 14 and 28. Arm A day 14 and Arm B day 28 data were combined as a NaPBA treatment Arm. Arm B day 14 and Arm A day 28 data were combined as a HPN-100 treatment Arm.


Secondary Outcome Measures:
  • Correlation Between 24-hour Urinary Phenylacetylglutamine (PAGN) Excretion (U-PAGN24-hour Excr) and Venous Ammonia AUC0-24 [ Time Frame: 28 Days ] [ Designated as safety issue: No ]
    The correlation between 24-hour urinary phenylacetylglutamine (PAGN) excretion (U-PAGN24-hour Excr) and venous ammonia AUC0-24 was summarized and the correlation was tested using the Spearman rank-order correlation.

  • Maximum Ammonia Values Observed on NaPBA Versus HPN-100 [ Time Frame: pre-dose, 2, 4, 8, 12, 16, 20 and 24 hours after first dose on days 14 and 28 ] [ Designated as safety issue: Yes ]
    Blood samples were collected at pre-dose, 2, 4, 8, 12, 16, 20 and 24 hours after first dose on days 14 and 28.

  • Rate (Percentage) of Ammonia Values Above Upper Limit of Normal (ULN) on NaPBA Versus HPN-100 [ Time Frame: on Day 14 and Day 28 ] [ Designated as safety issue: Yes ]
    NaPBA treated arm: total 345 blood samples were collected. HPN-100 treated arm: 343 blood samples were collected.

  • Number and Severity of Symptomatic Hyperammonemic Crises [ Time Frame: 29 Days ] [ Designated as safety issue: Yes ]
    Severity of symptomatic hyperammonemic crises was measured by peak ammonia level (µmol/L) when it is >= 100 µmol/L.

  • Rate of Adverse Events in Each Treatment Group [ Time Frame: 29 Days ] [ Designated as safety issue: Yes ]
  • Cmax for PAA of NaPBA and HPN-100 in Plasma [ Time Frame: pre-dose, 2, 4, 8, 12, 16, 20 and 24 hours after first dose on days 14 and 28 ] [ Designated as safety issue: No ]
    Blood samples were collected at pre-dose, 2, 4, 8, 12, 16, 20 and 24 hours after first dose on days 14 and 28.

  • Cmax for PBA of NaPBA and HPN-100 in Plasma [ Time Frame: pre-dose, 2, 4, 8, 12, 16, 20 and 24 hours after first dose on days 14 and 28 ] [ Designated as safety issue: No ]
    Blood samples were collected at pre-dose, 2, 4, 8, 12, 16, 20 and 24 hours after first dose on days 14 and 28.

  • Cmax PAGN of NaPBA and HPN-100 in Plasma [ Time Frame: pre-dose, 2, 4, 8, 12, 16, 20 and 24 hours after first dose on days 14 and 28 ] [ Designated as safety issue: No ]
    Blood samples were collected at pre-dose, 2, 4, 8, 12, 16, 20 and 24 hours after first dose on days 14 and 28.

  • U-PAGN24-hour Excr of NaPBA and HPN-100 [ Time Frame: 24 hours on Day 14 of each treatments ] [ Designated as safety issue: No ]

Enrollment: 46
Study Start Date: October 2009
Study Completion Date: September 2010
Primary Completion Date: September 2010 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: HPN-100
Subjects were be randomly assigned to receive either HPN-100 + NaPBA placebo or NaPBA + HPN 100 placebo for 2 weeks, and then crossed over to receive the other treatment for 2 weeks.
Drug: HPN-100
HPN-100 is a triglyceride that has a similar mechanism of action as NaPBA. It is a liquid with minimal taste and odor. Three teaspoons of HPN-100 (~17.4mL) delivers equivalent amount of PBA in 40 tablets of NaPBA.
Active Comparator: NaPBA
Subjects were randomly assigned to receive either HPN-100 + NaPBA placebo or NaPBA + HPN 100 placebo for 2 weeks, and then crossed over to receive the other treatment for 2 weeks.
Drug: Buphenyl (NaPBA)

  Eligibility

Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Diagnosis of UCD involving deficiencies of CPS, OTC, or ASS, confirmed via enzymatic, biochemical, or genetic testing
  • Adult UCD subjects 18 years of age or older who are being treated with NaPBA for their UCD; subjects must be on a stable dose of NaPBA for at least 1 week prior to the Day 1 visit. Subjects who are not receiving NaPBA at the initial screening visit, but who have the potential to benefit from treatment, may start receiving NaPBA during the screening period and be enrolled as long as they are on a stable dose of NaPBA for at least 1 week prior to Day 1.
  • No clinical evidence of hyperammonemia associated with an ammonia level of ≥ 100 μmol/L during the 2 weeks preceding screening
  • Signed informed consent by subject
  • Able to perform and comply with study activities, including blood draws and 24-hour urine samples
  • Negative pregnancy test for all females of childbearing potential
  • All females of childbearing age and all sexually active males must agree to use an acceptable method of contraception throughout the study. Appropriate contraceptive methods include hormonal contraceptives (oral, injected, implanted, or transdermal), tubal ligation, intrauterine device, hysterectomy, vasectomy, or double barrier methods. Abstinence is an acceptable form of birth control, though appropriate contraception must be used if the subject becomes sexually active.

Exclusion Criteria:

  • Screening or baseline ammonia level of ≥ 100 μmol/L or signs and symptoms indicative of hyperammonemia during the 2-week period preceding screening or enrollment; subjects may be re-screened after their ammonia is controlled and are stable for at least 14 days, at the discretion of the investigator
  • Use of any investigational drug within 30 days of Day 1
  • Active infection (viral or bacterial) or any other intercurrent condition (apart from UCD) that may increase ammonia levels
  • Any clinical or laboratory abnormality of Grade 3 or greater severity according to the Common Terminology Criteria for Adverse Events (CTCAE) v3.0, except Grade 3 elevations in liver enzymes, defined as levels 5-20 times ULN in alanine aminotransferase (ALT/SGPT), aspartate aminotransferase (AST/SGOT), or gamma glutamyl transpeptidase (GGT) in a clinically stable subject
  • Any clinical or laboratory abnormality or medical condition that, at the discretion of the investigator, may put the subject at increased risk by participating in this study
  • Use of any medication known to significantly affect renal clearance (e.g., probenecid) or to increase protein catabolism (e.g., corticosteroids), or other medication known to increase ammonia levels (e.g., valproate), within the 24 hours prior to Day 1 and throughout the study
  • Use of sodium benzoate within one week of Day 1
  • History of QTc interval prolongation or QTc interval > 450 msec at screening or baseline
  • Known hypersensitivity to phenylacetate (PAA) or phenylbutyrate (PBA)
  • Liver transplant, including hepatocellular transplant
  • Breastfeeding or lactating females
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00992459

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Sponsors and Collaborators
Hyperion Therapeutics, Inc.
  More Information

No publications provided by Hyperion Therapeutics, Inc.

Additional publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Hyperion Therapeutics, Inc.
ClinicalTrials.gov Identifier: NCT00992459     History of Changes
Other Study ID Numbers: HPN-100-006
Study First Received: October 8, 2009
Results First Received: April 4, 2013
Last Updated: July 10, 2013
Health Authority: United States: Food and Drug Administration

Keywords provided by Hyperion Therapeutics, Inc.:
Urea Cycle Disorder
UCD
GT4P
hyperammonemia
Buphenyl
glycerol phenylbutyrate
Sodium Phenylbutyrate

Additional relevant MeSH terms:
Urea Cycle Disorders, Inborn
Brain Diseases, Metabolic, Inborn
Brain Diseases, Metabolic
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases
Amino Acid Metabolism, Inborn Errors
Metabolism, Inborn Errors
Genetic Diseases, Inborn
Metabolic Diseases
4-phenylbutyric acid
Antineoplastic Agents
Therapeutic Uses
Pharmacologic Actions

ClinicalTrials.gov processed this record on August 18, 2014