A Study of Safety and Efficacy of HPN-100 in Subjects With Cirrhosis and Episodic Hepatic Encephalopathy (HALT-HE)
This is a phase 2 study of HPN-100 in subjects with hepatic encephalopathy (HE) consisting of an open label safety lead-in (Part A), followed by randomized, double-blind, placebo-controlled treatment (Part B).
|Study Design:||Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
|Official Title:||A Phase 2, Randomized, Double-Blind, Placebo-Controlled Study of the Safety and Efficacy of HPN-100 for Maintaining Remission in Subjects With Cirrhosis and Episodic Hepatic Encephalopathy|
- Part A: The Rate of AEs and Tolerability of HPN-100 [ Time Frame: Part A: 28 days ] [ Designated as safety issue: Yes ]Part A: The rate of AEs and tolerability of 6 mL and 9 mL doses of HPN-100 were considered the primary safety endpoints for Part A. Safety assessments included adverse events, laboratory tests (including ammonia, hematology, coagulation, liver function and serum chemistry parameters), vital signs, physical and neurological examinations, and electrocardiograms.
- Part B: Proportion of Subjects Who Exhibit an HE Episode, Defined as Either of the Following During the Treatment Phase: WH ≥2; WH Grade and Asterixis Grade Increase of 1 Each, if Baseline WH = 0 [ Time Frame: Part B: 112 Days ] [ Designated as safety issue: Yes ]
An HE event was defined as occurrences of either a West Haven (WH) Grade ≥2 or a WH Grade 1 and asterixis grade increase of 1 (if baseline WH = 0).
The WH criteria are widely used for rating the severity of HE and are summarized below:
Grade 1: trivial lack of awareness, euphoria or anxiety, shortened attention span, impaired performance of addition Grade 2: lethargy or apathy, minimal disorientation for time or place, subtle personality change, inappropriate behavior, impaired performance of subtraction Grade 3: somnolence to semi-stupor but responsive to verbal stimuli, confusion, gross disorientation Grade 4: coma (unresponsive to verbal or noxious stimuli)
Asterixis was assessed after arm and forearm extension along with wrist dorsiflexion for 30 seconds and assigned a grade according to the following criteria:
Grade 1: rare flaps Grade 2: occasional irregular flaps Grade 3: frequent flaps Grade 4: continuous flaps
- Total Number of HE Events [ Time Frame: 112 Days ] [ Designated as safety issue: No ]Secondary efficacy endpoint. The total number of HE events during the treatment phase for subjects in the placebo and active arms.
- Time to Meeting the Primary Endpoint [ Time Frame: 112 Days ] [ Designated as safety issue: No ]Secondary efficacy endpoint. The time to the first HE episode during the treatment period was calculated using the Kaplan-Meier method. Subjects who did not experience an HE episode were censored at the time of their last asterixis assessment. Subjects who had no post-randomization data for the primary endpoint were considered to have an HE episode at Day 1.
- Change From Baseline in Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) Score [ Time Frame: Day 56, Final Visit (D112) ] [ Designated as safety issue: No ]Changes from Baseline to Day 56 and the Final Visit were compared between treatment groups using an ANCOVA model for the total index RBANS score ). The index score is a sum of the scores for each of the 5 individual domains (immediate memory, visuospatial/constructional, language, attention). The minimum and maximum total index scores are 40 and 160, respectively; a higher score is better.
|Study Start Date:||December 2009|
|Study Completion Date:||April 2012|
|Primary Completion Date:||April 2012 (Final data collection date for primary outcome measure)|
Part B: 6 mL BID for 16 weeks.
|Placebo Comparator: Placebo||
Part B: same as experimental arm
Other Name: Placebo
Part A: Open-label, dose-escalation lead-in to assess HPN-100 safety and PK Approximately 10 subjects with HE and cirrhosis classified as Child Pugh B or C will undergo a one-step dose escalation over 4 weeks. Subjects will initially receive 6 mL HPN-100 BID for 1 week. On Day 7 and following satisfactory safety assessment of the subject, the dose will be escalated to 9 mL BID for an additional 3 weeks.
In addition to a safety assessment, subjects will undergo 12-hour PK assessments on Days 7 and 28, with sampling at the following time points (relative to the first dose): 0 (pre-first daily dose of HPN-100), 2, 4, 8 (approximately 2 hours before the second daily dose of HPN 100), and 12 hours post-first dose (approximately 2 hours after the second daily dose of HPN-100). Additional PK samples will be collected on Days 8, 15, and 21 (at pre-first dose and 4 hours post-first dose).
The DSMB will review all safety information, including laboratory values, to determine if Part B may be initiated.
Subjects enrolled in Part A may be eligible for Part B as long as they meet the eligibility criteria.
Part B: Randomized, double-blind assessment of HPN-100 in HE subjects Subjects who meet all entry criteria and are judged to be compliant with their prescribed SOC will be eligible for randomization to receive either HPN-100 or matching placebo for 16 weeks. Efficacy will be assessed by the proportion of subjects experiencing episodes of HE, as well as by other outcome measures, including daily home assessments.
Please refer to this study by its ClinicalTrials.gov identifier: NCT00999167
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