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Phase 2B Efficacy/Safety of Ornithine Phenylacetate in Hospitalized Cirrhotic Patients With Hepatic Encephalopathy (STOP-HE)

Multicenter, Randomized Phase 2B Study to Evaluate the Efficacy, Safety and Tolerability of OCR-002 (Ornithine Phenylacetate) in Hospitalized Patients With Cirrhosis and Associated Hyperammonemia With an Episode of Hepatic Encephalopathy (STOP-HE Study)

Status
Completed
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT01966419
Acronym
STOP-HE
Enrollment
231
Registered
2013-10-21
Start date
2014-01-07
Completion date
2016-12-29
Last updated
2021-09-16

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Acute Episode of Overt Hepatic Encephalopathy, Hepatic Encephalopathy

Keywords

hepatic encephalopathy, hyperammonemia, cirrhosis, ornithine phenylacetate, OCR-002

Brief summary

The purpose of this study is to determine whether ornithine phenylacetate can speed recovery from an acute hepatic encephalopathy episode requiring hospitalization in cirrhotic patients.

Detailed description

The primary objectives of the study were to evaluate the efficacy of OCR-002 for treatment of an acute hepatic encephalopathy (HE) episode in cirrhotic patients requiring hospitalization and the safety and tolerability of OCR-002 in hospitalized cirrhotic patients with an acute episode of HE.

Interventions

Ornithine phenylacetate for continuous IV infusion at dose levels predicated on level of hepatic decompensation

Placebo for continuous IV infusion that is visually identical to the experimental product

Sponsors

Ocera Therapeutics, Inc.
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Investigator)

Masking description

While the study was double-blind (participant and investigator blinded), the care provider and outcomes assessor were also blinded.

Eligibility

Sex/Gender
ALL
Age
18 Years to 75 Years
Healthy volunteers
No

Inclusion criteria

* Hospitalized with an acute episode of hepatic encephalopathy as complication of cirrhosis * Elevated venous ammonia

Exclusion criteria

* Renal failure with serum creatinine \> 3 mg/dL or need for dialysis * Molecular Adsorbent Recirculation System utilized * Pregnancy or breastfeeding

Design outcomes

Primary

MeasureTime frameDescription
Percentage of Participants in Each HE StageBaseline to End of Study (through 3 hours post end-of-infusion)To support the primary endpoint of confirmed clinical response, the investigator rated participants on a 4-point staging scale, where higher scores are worse. The stages are described as: Stage 0/1 = Participant has no tremor of the hand when the wrist is extended (asterixis) and no confusion, even about where they are (disorientation) Stage 2 = Participant has tremor of the hand when the wrist is extended (asterixis) and is confused, not knowing where they are (disorientation) Stage 3 = Participant is tired, falling asleep, answers questions but is confused, and doesn't know where they are (Stupor, arousable but falls asleep, responsive to verbal stimuli, Obvious confusion, Gross disorientation) Stage 4 = Participant is unconscious (in a coma)

Countries

Australia, Austria, Belgium, Bulgaria, Czechia, Denmark, Estonia, France, Germany, Hungary, Israel, Italy, Netherlands, New Zealand, Russia, Spain, United States

Participant flow

Recruitment details

A total of 231 participants were enrolled (randomized) into the trial at multiple sites in the United States, Australia and Europe.

Participants by arm

ArmCount
Placebo
Participants receive matching placebo up to 5 days via continuous IV infusion in addition to SOC
115
Ornithine Phenylacetate
Participants receive ornithine phenylacetate up to 5 days via continuous IV infusion in addition to SOC
116
Total231

Baseline characteristics

CharacteristicPlaceboTotalOrnithine Phenylacetate
Age, Continuous60 years
STANDARD_DEVIATION 9.5
59 years
STANDARD_DEVIATION 9.6
50 years
STANDARD_DEVIATION 9.8
Ethnicity (NIH/OMB)
Hispanic or Latino
7 Participants18 Participants11 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
57 Participants112 Participants55 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
51 Participants101 Participants50 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants1 Participants1 Participants
Race (NIH/OMB)
Asian
1 Participants2 Participants1 Participants
Race (NIH/OMB)
Black or African American
8 Participants13 Participants5 Participants
Race (NIH/OMB)
More than one race
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
1 Participants1 Participants0 Participants
Race (NIH/OMB)
Unknown or Not Reported
51 Participants101 Participants50 Participants
Race (NIH/OMB)
White
54 Participants113 Participants59 Participants
Region of Enrollment
Australia
1 participants1 participants0 participants
Region of Enrollment
Austria
2 participants7 participants5 participants
Region of Enrollment
Belgium
6 participants7 participants1 participants
Region of Enrollment
Bulgaria
2 participants3 participants1 participants
Region of Enrollment
Canada
2 participants2 participants0 participants
Region of Enrollment
Czechia
4 participants5 participants1 participants
Region of Enrollment
Denmark
2 participants2 participants0 participants
Region of Enrollment
France
11 participants21 participants10 participants
Region of Enrollment
Hungary
1 participants5 participants4 participants
Region of Enrollment
Israel
11 participants22 participants11 participants
Region of Enrollment
Italy
0 participants2 participants2 participants
Region of Enrollment
Netherlands
1 participants1 participants0 participants
Region of Enrollment
Russia
7 participants12 participants5 participants
Region of Enrollment
Spain
3 participants13 participants10 participants
Region of Enrollment
United States
62 participants128 participants66 participants
Sex: Female, Male
Female
37 Participants81 Participants44 Participants
Sex: Female, Male
Male
78 Participants150 Participants72 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
15 / 11211 / 114
other
Total, other adverse events
31 / 11230 / 114
serious
Total, serious adverse events
34 / 11229 / 114

Outcome results

Primary

Percentage of Participants in Each HE Stage

To support the primary endpoint of confirmed clinical response, the investigator rated participants on a 4-point staging scale, where higher scores are worse. The stages are described as: Stage 0/1 = Participant has no tremor of the hand when the wrist is extended (asterixis) and no confusion, even about where they are (disorientation) Stage 2 = Participant has tremor of the hand when the wrist is extended (asterixis) and is confused, not knowing where they are (disorientation) Stage 3 = Participant is tired, falling asleep, answers questions but is confused, and doesn't know where they are (Stupor, arousable but falls asleep, responsive to verbal stimuli, Obvious confusion, Gross disorientation) Stage 4 = Participant is unconscious (in a coma)

Time frame: Baseline to End of Study (through 3 hours post end-of-infusion)

Population: Intention to Treat Analysis Set (Note: all participants did not start at the same time)

ArmMeasureGroupValue (NUMBER)
PlaceboPercentage of Participants in Each HE StageDay 1, 5 pm : Missing0 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 4, 7 am : Stage 35 percentage of participants
PlaceboPercentage of Participants in Each HE StageBaseline : Stage 330 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 4, 7 am : Stage 242 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 2, 7 am : Stage 43 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 4, 7 am : Stage 0/128 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 3, 7 am : Stage 43 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 1, 7 am : Stage 30 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 2, 7 am : Stage 321 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 4, 7 am : Missing0 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 3, 7 am : Missing0 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 2, 7 am : Stage 261 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 4, 5 pm : Stage 42 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 1, 7 am : Stage 22 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 5, 5 pm : Stage 0/123 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 4, 5 pm : Stage 35 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 2, 7 am : Stage 0/110 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 4, 5 pm : Stage 242 percentage of participants
PlaceboPercentage of Participants in Each HE StageBaseline : Stage 271 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 4, 5 pm : Stage 0/128 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 2, 7 am : Missing0 percentage of participants
PlaceboPercentage of Participants in Each HE StageEnd of Study : Missing0 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 1, 7 am : Stage 0/10 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 5, 5 pm : Missing0 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 2, 5 pm : Stage 43 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 6, 7 am : Stage 40 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 3, 7 am : Stage 0/121 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 6, 7 am : Stage 310 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 2, 5 pm : Stage 314 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 6, 7 am : Stage 221 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 1, 7 am : Missing0 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 6, 7 am : Stage 0/123 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 2, 5 pm : Stage 257 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 6, 7 am : Missing0 percentage of participants
PlaceboPercentage of Participants in Each HE StageBaseline : Stage 0/10 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 6, 5 pm : Stage 40 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 2, 5 pm : Stage 0/116 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 6, 5 pm : Stage 33 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 1, 5 pm : Stage 40 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 6, 5 pm : Stage 25 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 3, 5 pm : Stage 43 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 6, 5 pm : Stage 0/16 percentage of participants
PlaceboPercentage of Participants in Each HE StageBaseline : Stage 411 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 6, 5 pm : Missing0 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 3, 5 pm : Stage 37 percentage of participants
PlaceboPercentage of Participants in Each HE StageEnd of Study : Stage 45 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 2, 5 pm : Missing0 percentage of participants
PlaceboPercentage of Participants in Each HE StageEnd of Study : Stage 310 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 1, 5 pm : Stage 37 percentage of participants
PlaceboPercentage of Participants in Each HE StageEnd of Study : Stage 231 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 3, 5 pm : Stage 246 percentage of participants
PlaceboPercentage of Participants in Each HE StageEnd of Study : Stage 0/145 percentage of participants
PlaceboPercentage of Participants in Each HE StageBaseline : Missing3 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 5, 5 pm : Stage 224 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 4, 5 pm : Missing0 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 1, 5 pm : Stage 232 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 5, 7 am : Stage 40 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 3, 7 am : Stage 250 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 5, 7 am : Stage 39 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 3, 5 pm : Stage 0/120 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 5, 7 am : Stage 229 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 1, 5 pm : Stage 0/10 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 5, 7 am : Stage 0/123 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 3, 5 pm : Missing0 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 5, 7 am : Missing0 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 1, 7 am : Stage 40 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 5, 5 pm : Stage 40 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 4, 7 am : Stage 42 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 5, 5 pm : Stage 38 percentage of participants
PlaceboPercentage of Participants in Each HE StageDay 3, 7 am : Stage 315 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 5, 5 pm : Stage 33 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 3, 7 am : Stage 310 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 3, 7 am : Stage 255 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 3, 7 am : Stage 0/125 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 3, 7 am : Missing0 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageBaseline : Stage 46 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageBaseline : Stage 340 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageBaseline : Stage 268 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageBaseline : Stage 0/10 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageBaseline : Missing2 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 1, 7 am : Stage 40 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 1, 7 am : Stage 34 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 1, 7 am : Stage 23 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 1, 7 am : Stage 0/10 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 1, 7 am : Missing0 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 1, 5 pm : Stage 45 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 1, 5 pm : Stage 314 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 1, 5 pm : Stage 236 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 1, 5 pm : Stage 0/11 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 1, 5 pm : Missing0 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 2, 7 am : Stage 44 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 2, 7 am : Stage 315 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 2, 7 am : Stage 269 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 2, 7 am : Stage 0/110 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 2, 7 am : Missing0 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 2, 5 pm : Stage 44 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 2, 5 pm : Stage 39 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 2, 5 pm : Stage 261 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 2, 5 pm : Stage 0/116 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 3, 5 pm : Stage 43 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 3, 5 pm : Stage 39 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 2, 5 pm : Missing0 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 3, 5 pm : Stage 245 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageEnd of Study : Stage 0/155 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 3, 5 pm : Stage 0/127 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 3, 5 pm : Missing0 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 4, 7 am : Stage 40 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 4, 7 am : Stage 39 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 4, 7 am : Stage 240 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 4, 7 am : Stage 0/130 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 3, 7 am : Stage 42 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 5, 5 pm : Stage 222 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 4, 7 am : Missing0 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 4, 5 pm : Stage 40 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 4, 5 pm : Stage 37 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 4, 5 pm : Stage 234 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 4, 5 pm : Stage 0/128 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 5, 5 pm : Stage 0/128 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 5, 5 pm : Missing0 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 6, 7 am : Stage 40 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 6, 7 am : Stage 33 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 6, 7 am : Stage 224 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 6, 7 am : Stage 0/127 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 6, 7 am : Missing0 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 6, 5 pm : Stage 40 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 6, 5 pm : Stage 33 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 6, 5 pm : Stage 27 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 6, 5 pm : Stage 0/15 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 6, 5 pm : Missing0 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageEnd of Study : Stage 43 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageEnd of Study : Stage 37 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageEnd of Study : Stage 228 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageEnd of Study : Missing0 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 4, 5 pm : Missing0 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 5, 7 am : Stage 40 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 5, 7 am : Stage 37 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 5, 7 am : Stage 228 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 5, 7 am : Stage 0/132 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 5, 7 am : Missing0 percentage of participants
Ornithine PhenylacetatePercentage of Participants in Each HE StageDay 5, 5 pm : Stage 40 percentage of participants

Source: ClinicalTrials.gov · Data processed: Feb 17, 2026