Trial · NCT01257737

To Evaluate the Safety of Long-term Use of HPN-100 in the Management of Urea Cycle Disorders (UCDs)

NCT01257737, Phase 4, Completed, Amgen; results first posted 2018-05-04

3 sourcestrials-2026-11-12-0.5.0

Cite this record

ConductScience Library. To Evaluate the Safety of Long-term Use of HPN-100 in the Management of Urea Cycle Disorders (UCDs). Trials, record NCT01257737. Release trials-2026-11-12-0.5.0, 12 Nov 2026. https://conductscience.org/library/trials/NCT01257737

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Trial

As registered on ClinicalTrials.gov, in the graph's capture of the registry.

Title: To Evaluate the Safety of Long-term Use of HPN-100 in the Management of Urea Cycle Disorders (UCDs)
NCT number: NCT01257737
Status: Completed
Phases: Phase 4
Enrollment: 88 participants, actual
Lead sponsor: Amgen
Conditions: Urea Cycle Disorders
Interventions: HPN-100
First posted: 2010-12-10
Last updated: 2024-08-22
Results first posted: 2018-05-04

Source ClinicalTrials.gov

Registered outcomes9

Each outcome the trial registered, primary first, in ClinicalTrials.gov's words.

List	Outcome	Time frame	Description
Primary	Number of Participants With at Least One Adverse Event	From the time of informed consent until 7 days after the last dose of study drug, up to 66 months	Safety was assessed by the incidence of treatment-emergent adverse events (TEAEs) and treatment-emergent serious adverse events (SAEs). An AE/adverse experience was any untoward medical occurrence in a patient or clinical investigation subject administered a pharmaceutical product and which did not necessarily have a causal relationship with this treatment. For additional information regarding adverse events, please see the safety section of the record.
Secondary	Mean Normalized Blood Ammonia Levels	From baseline through the end of the study, up to 66 months	Blood samples were collected for the assessment of plasma ammonia concentrations at baseline, at least every 6 months, at all unscheduled visits, and at the end of study participation. Ammonia level data were obtained from different local laboratories and each laboratory may have used a slightly different normal reference range. Therefore, the ammonia level data were normalized to a standard laboratory reference range before performing any analysis of ammonia data.
Secondary	Number of Hyperammonemic Crises	From the time of informed consent until 7 days after the last dose of study drug, up to 66 months	An hyperammonemic crisis (HAC) was defined as clinical symptoms associated with a venous ammonia concentration of ≥100 μmol/L.
Secondary	Causes of Hyperammonemic Crises	From the time of informed consent until 7 days after the last dose of study drug, up to 66 months	An hyperammonemic crisis (HAC) was defined as clinical symptoms associated with a venous ammonia concentration of ≥100 μmol/L. Peak observed ammonia concentrations during an HAC, precipitating factors, and symptoms recorded as suggestive to hyperammonemia were documented. There can be multiple contributing factors to an hyperammonemic crisis; in some cases several causes were identified.
Secondary	Mean Wechsler Abbreviated Scale of Intelligence (WASI) Scores	Baseline, Month 12, Month 24, Month 36, Month 48, and study exit visit (up to 66 months)	The Wechsler Abbreviated Scale of Intelligence (WASI) was administered to adults and pediatric participants who were at least 6 years of age. It was used to estimate general intellectual ability (IQ) based on the vocabulary and matrix reasoning subtests. The vocabulary subtest included 4 images and 38 verbal items. In the matrix reasoning subtest, the participant viewed 35 incomplete grid patterns and was asked to complete the pattern using responses from 5 possible choices. The number of correct responses for each of the subtests was converted to a T-score using the WASI assessment manual; T-scores are standard scores with a mean of 50 and a standard deviation (SD) of 10. Raw scores for the 2 subtests were summed, and converted to a standard score (mean of 100 with SD of 15) for the general IQ score for adults and to a T-score for children in accordance with the WASI manual. Higher scores indicate a higher level of intelligence.
Secondary	Mean Child Behavior Checklist (CBCL) Problems Scores	Baseline, Month 12, Month 24, and study exit visit (up to 66 months)	The Child Behavior Checklist (CBCL) is a widely-used method of identifying problem behavior. Two versions of the CBCL were used in this study; the assessment for children 6-18 years of age was used for participants ≥6 years of age, and the assessment for children 1.5-5 years of age was used for those who were at least 5 years old but \<6 years of age. Parents/caregivers answered questions (120 and 100 questions, respectively, for the older and younger populations) using a 3-point Likert scale (0= not true; 1= somewhat or sometimes true; 2 =very true or often true). Using a computer program, responses to similar questions were grouped together into 20 domains (e.g., activities, social, school, etc.), and domain response scores were converted to T-scores and percentiles. A mean score of 50 is average, with a standard deviation of 10 points. Higher scores indicate greater problems. The total problems score is the sum of all of the problem items.
Secondary	Mean Behavior Rating Inventory of Executive Function (BRIEF) Scores	Baseline, Month 12, Month 24, and study exit visit (up to 66 months)	The Behavior Rating Inventory of Executive Function (BRIEF) is designed to assess executive functioning in children and adolescents ages 5 to 18 years of age. Parents/caregivers answered 86 questions on a 3-point scale (never, sometimes, often). Similar questions were grouped together into 8 scales; these scales were summed to produce 2 index measures and a global executive composite score. Raw scores for the indices/scales and composite score were converted to T-scores with corresponding 90% confidence intervals using computer software. Higher T-scores indicate a higher level of dysfunction.
Secondary	Mean California Verbal Learning Test Scores: List A Total 1-5 T-Scores	Baseline, Month 12, Month 24, Month 36, Month 48, and study exit visit (up to 66 months)	The California Verbal Learning Test - Second Edition (CVLT-II) assesses recall and recognition of word lists over several immediate- and delayed-memory trials. In the learning phase, adult participants were presented a list of 16 words (List A; 4 words each in 4 categories \[e.g., fruit, toys, etc.\]) for 5 trials, but words from the same category were never presented consecutively. An interference list (List B) of 16 different words was then presented for 1 trial. Short-and long-delay recalls for List A, yes/no recognition trials of List A, and a forced-choice recognition trial of List A was also administered. The total score for the 5 immediate-recall trials was converted to a T-score. Lower T-scores reflect worse performance.
Secondary	Mean California Verbal Learning Test Scores: Short and Long Delay Free Recall, Short and Long Delay Cued Recall, CVLT-II-Learning Slope, and Total Word Recognition Discrimination	Baseline, Month 12, Month 24, Month 36, Month 48, and study exit visit (up to 66 months)	The California Verbal Learning Test - Second Edition (CVLT-II) assesses recall and recognition of word lists over several immediate- and delayed-memory trials. In the learning phase, adult participants were presented a list of 16 words (List A; 4 words each in 4 categories \[e.g., fruit, toys, etc.\]) for 5 trials, but words from the same category were never presented consecutively. An interference list (List B) of 16 different words was then presented for 1 trial. Short-and long-delay recalls for List A, yes/no recognition trials of List A, and a forced-choice recognition trial of List A was also administered. The scores for the learning slope, the short- and long-delay scores and total word recognition discrimination scores were converted to Z-scores by computer software. The CVLT-II Z-score has a mean of 0 and a standard deviation of 1. Negative scores indicate below-average performance.

Source ClinicalTrials.gov

Outcomes9

Each outcome the trial posted results for, in ClinicalTrials.gov's words.

Type	Outcome	Time frame	Population	Units	Measured as
PRIMARY	Number of Participants With at Least One Adverse Event	From the time of informed consent until 7 days after the last dose of study drug, up to 66 months	Safety Population: All participants who received any amount of study medication	Participants	COUNT_OF_PARTICIPANTS
SECONDARY	Mean Normalized Blood Ammonia Levels	From baseline through the end of the study, up to 66 months	Participants with available data	μmol/L	MEAN
SECONDARY	Number of Hyperammonemic Crises	From the time of informed consent until 7 days after the last dose of study drug, up to 66 months	Safety Population: All participants who received any amount of study medication	Number of crises	NUMBER
SECONDARY	Causes of Hyperammonemic Crises	From the time of informed consent until 7 days after the last dose of study drug, up to 66 months	Participants who experienced hyperammonemic crises	Number of crises	NUMBER
SECONDARY	Mean Wechsler Abbreviated Scale of Intelligence (WASI) Scores	Baseline, Month 12, Month 24, Month 36, Month 48, and study exit visit (up to 66 months)	Participants ≥ 6 years of age with available data; data were not analyzed for the 5 ongoing participants in Canada after the cutoff for the clinical study report (29 Oct 2015).	T-score	MEAN
SECONDARY	Mean Child Behavior Checklist (CBCL) Problems Scores	Baseline, Month 12, Month 24, and study exit visit (up to 66 months)	Participants 5-18 years of age with available data; data were not analyzed for the 1 ongoing pediatric participant in Canada after the cutoff for the clinical study report (29 Oct 2015).	T-Score	MEAN
SECONDARY	Mean Behavior Rating Inventory of Executive Function (BRIEF) Scores	Baseline, Month 12, Month 24, and study exit visit (up to 66 months)	Participants 5-18 years of age with available data; data were not analyzed for the 1 ongoing pediatric participant in Canada after the cutoff for the clinical study report (29 Oct 2015).	T-Score	MEAN
SECONDARY	Mean California Verbal Learning Test Scores: List A Total 1-5 T-Scores	Baseline, Month 12, Month 24, Month 36, Month 48, and study exit visit (up to 66 months)	Adult participants (age 19-61) with available data; data were not analyzed for the 4 ongoing adult participants in Canada after the cutoff for the clinical study report (29 Oct 2015).	T-Score	MEAN
SECONDARY	Mean California Verbal Learning Test Scores: Short and Long Delay Free Recall, Short and Long Delay Cued Recall, CVLT-II-Learning Slope, and Total Word Recognition Discrimination	Baseline, Month 12, Month 24, Month 36, Month 48, and study exit visit (up to 66 months)	Adult participants (age 19-61) with available data; data were not analyzed for the 4 ongoing adult participants in Canada after the cutoff for the clinical study report (29 Oct 2015).	Z-Score	MEAN

Source ClinicalTrials.gov

Results by group171

Each measurement the trial posted, group by group, in the words and numbers it posted.

Outcome	Group	Category	Value	Spread	Units
Number of Participants With at Least One Adverse Event	HPN-100- Pediatric		34		Participants
Number of Participants With at Least One Adverse Event	HPN-100 - Adult		40		Participants
Mean Normalized Blood Ammonia Levels	HPN-100- Pediatric	Baseline	19.445	Standard Deviation 16.4478	μmol/L
Mean Normalized Blood Ammonia Levels	HPN-100 - Adult	Baseline	26.005	Standard Deviation 23.4156	μmol/L
Mean Normalized Blood Ammonia Levels	HPN-100- Pediatric	Month 6	18.437	Standard Deviation 14.7127	μmol/L
Mean Normalized Blood Ammonia Levels	HPN-100 - Adult	Month 6	24.235	Standard Deviation 18.2070	μmol/L
Mean Normalized Blood Ammonia Levels	HPN-100- Pediatric	Month 12	18.236	Standard Deviation 13.7955	μmol/L
Mean Normalized Blood Ammonia Levels	HPN-100 - Adult	Month 12	27.843	Standard Deviation 20.3701	μmol/L
Mean Normalized Blood Ammonia Levels	HPN-100- Pediatric	Month 18	25.145	Standard Deviation 26.2123	μmol/L
Mean Normalized Blood Ammonia Levels	HPN-100 - Adult	Month 18	31.378	Standard Deviation 26.1624	μmol/L

1 to 10 of 171Source ClinicalTrials.gov

See all 171 results by group

Participant flow6

How many started, completed or left each group, period by period.

Period	Milestone	Group	Participants
Overall Study	STARTED	HPN-100- Pediatric	45
Overall Study	STARTED	HPN-100 - Adult	43
Overall Study	COMPLETED	HPN-100- Pediatric	43
Overall Study	COMPLETED	HPN-100 - Adult	39
Overall Study	NOT COMPLETED	HPN-100- Pediatric	2
Overall Study	NOT COMPLETED	HPN-100 - Adult	4

Source ClinicalTrials.gov

Adverse events88

Each adverse event the trial posted, group by group: the participants affected out of those at risk.

Type	Event	Organ system	Group	Affected	At risk
other	Diarrhoea	Gastrointestinal disorders	HPN-100- Pediatric	3	45
other	Diarrhoea	Gastrointestinal disorders	HPN-100 - Adult	7	43
other	Nausea	Gastrointestinal disorders	HPN-100- Pediatric	2	45
other	Nausea	Gastrointestinal disorders	HPN-100 - Adult	4	43
other	Vomiting	Gastrointestinal disorders	HPN-100- Pediatric	6	45
other	Vomiting	Gastrointestinal disorders	HPN-100 - Adult	5	43
other	Pain	General disorders	HPN-100- Pediatric	1	45
other	Pain	General disorders	HPN-100 - Adult	3	43
other	Pyrexia	General disorders	HPN-100- Pediatric	3	45
other	Pyrexia	General disorders	HPN-100 - Adult	2	43

1 to 10 of 88Source ClinicalTrials.gov

See all 88 adverse events

Adverse event totals6

The totals the trial posted for each group.

Total	Group	Affected	At risk
Total, all-cause mortality	HPN-100- Pediatric	0	45
Total, all-cause mortality	HPN-100 - Adult	0	43
Total, other adverse events	HPN-100- Pediatric	26	45
Total, other adverse events	HPN-100 - Adult	27	43
Total, serious adverse events	HPN-100- Pediatric	12	45
Total, serious adverse events	HPN-100 - Adult	19	43

Source ClinicalTrials.gov

Papers0

The papers the trial lists on ClinicalTrials.gov.

None in this release.

Grants0

The grants NIH RePORTER links to the trial, newest funded first: NIH's, and some of AHRQ's, CDC's, FDA's and VA's. Each shows its title, principal investigators, organization and funder in its newest year.

None in this release.

Trial comparisons3

Comparisons of the trial's two groups, calculated by ConductScience from the counts it posted.

Comparison	Source
HPN-100- Pediatric vs HPN-100 - Adult: Number of Participants With at Least One Adverse Event	Trial comparisons
HPN-100- Pediatric vs HPN-100 - Adult: deaths from any cause	Trial comparisons
HPN-100- Pediatric vs HPN-100 - Adult: serious adverse events	Trial comparisons

Tests3

The ConductCognition tests this trial's registered outcomes name, as ScienceGraph matched them in trial-tests-2026-11-12-0.2.1.

Test	Named as	Source
Matrix Reasoning	Secondary outcome	ConductCognition
Verbal Learning	Secondary outcome	ConductCognition
Vocabulary Test	Secondary outcome	ConductCognition

Data dates

The day each source was copied for this release.

ClinicalTrials.gov: 2026-11-12; ClinicalTrials.gov
Results, from AACT: 2026-03-23; AACT
NIH grant links: 2026-11-13; NIH RePORTER

Sources 3

ClinicalTrials.gov's posted results, through CTTI's AACTFreely available. Acknowledgement requested
ClinicalTrials.govNo license stated
NIH RePORTER's clinical studies and project filesPublic domain

Each source's terms

ClinicalTrials.gov's posted results, through CTTI's AACTClinicalTrials.gov data via Aggregate Analysis of ClinicalTrials.gov (AACT), CTTI. CTTI makes its materials freely available and requests acknowledgement. https://aact.ctti-clinicaltrials.org/documentation/299
ClinicalTrials.govnone stated
NIH RePORTER's clinical studies and project filesPublic domain (NIH RePORTER)

ClinicalTrials.gov's data carry an international copyright outside the United States: https://clinicaltrials.gov/about-site/terms-conditions.

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The record and each of its lists are JSON, twenty rows a page. No key.

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