Completed

A Dose Response Study of a Caspase Inhibitor in Hepatitis C Patients

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What is being tested

IDN-6556

+ Placebo
Drug
Who is being recruted

Blood-Borne Infections
+16

+ Chronic Disease
+ Communicable Diseases
Over 18 Years
See all eligibility criteria
How is the trial designed

Treatment Study

Placebo-Controlled
Phase 2
Interventional
Study Start: July 2004
See protocol details

Summary

Principal SponsorConatus Pharmaceuticals Inc.
Last updated: December 11, 2025
Sourced from a government-validated database.Claim as a partner
Study start date: July 1, 2004Actual date on which the first participant was enrolled.

The purpose of this study is to determine if IDN-6556, when given orally, is safe and effective in patients with chronic hepatitis C virus infection.

Official TitleA Dose Response Study of a Caspase Inhibitor in Hepatitis C Patients 
NCT00088140
Principal SponsorConatus Pharmaceuticals Inc.
Last updated: December 11, 2025
Sourced from a government-validated database.Claim as a partner

Protocol

This section provides details of the study plan, including how the study is designed and what the study is measuring.
Design Details
204 patients to be enrolledTotal number of participants that the clinical trial aims to recruit.
Treatment Study
These studies test new ways to treat a disease, condition, or health issue. The goal is to see if a new drug, therapy, or approach works better or has fewer side effects than existing options.

How participants are assigned to different groups/arms
In this clinical study, participants are placed into groups randomly, like flipping a coin. This ensures that the study is fair and unbiased, making the results more reliable. By assigning participants by chance, researchers can better compare treatments without external influences.

Other Ways to Assign Participants
Non-randomized allocation: Participants are assigned based on specific factors, such as their medical condition or a doctor's decision.
None (Single-arm trial): If the study has only one group, all participants receive the same treatment, and no allocation is needed.

How treatments are given to participants
Participants are divided into different groups, each receiving a specific treatment at the same time. This helps researchers compare how well different treatments work against each other.

Other Ways to Assign Treatments
Single-group assignment: Everyone gets the same treatment.
Cross-over assignment: Participants switch between treatments during the study.
Factorial assignment: Participants receive different combinations of treatments.
Sequential assignment: Participants receive treatments one after another in a specific order, possibly based on individual responses.
Other assignment: Treatment assignment does not follow a standard or predefined design.

How the effectiveness of the treatment is controlled
In a placebo-controlled study, some participants receive the experimental treatment, while others receive an inert substance (placebo) to compare outcomes. This method helps to isolate the effect of the treatment from the psychological effects of receiving any treatment at all.

Other Options
Non-placebo-controlled: No placebo is used. All participants receive the actual treatment or alternative interventions (often the Standard of Care), and comparisons are made between these treatments.

How the interventions assigned to participants is kept confidential
Participants, researchers, outcome assessors, and care providers do not know which treatment is being given. This is the most complete way to prevent bias and keep the study as neutral as possible.

Other Ways to Mask Information
Open-label: Everyone knows which treatment is being given.
Single-blind: Participants do not know which treatment they are receiving, but researchers do.
Double-blind: Neither participants nor researchers know which treatment is given.
Triple-blind: Participants, researchers, and outcome assessors do not know which treatment is given.

Eligibility

Researchers look for people who fit a certain description, called eligibility criteria: person's general health condition or prior treatments.
Conditions
Criteria
Any sexBiological sex of participants that are eligible to enroll.
Over 18 YearsRange of ages for which participants are eligible to join.
Healthy volunteers not allowedIf individuals who are healthy and do not have the condition being studied can participate.
Conditions
Pathology
Blood-Borne Infections
Chronic Disease
Communicable Diseases
Digestive System Diseases
Enterovirus Infections
Hepatitis
Hepatitis A
Hepatitis, Chronic
Hepatitis, Viral, Human
Hepatitis C
Infections
Liver Diseases
Pathologic Processes
Picornaviridae Infections
RNA Virus Infections
Virus Diseases
Flaviviridae Infections
Hepatitis C, Chronic
Disease Attributes
Criteria

Inclusion Criteria: * Chronic hepatitis C infection * Unsuccessful prior HCV treatment * Liver impairment (either AST or ALT 1.5-10.0 x ULN) * Alpha-fetoprotein \<= 50 ng/mL * Adequate hematologic parameters Exclusion Criteria: * Decompensated or severe liver disease * Hepatocellular carcinoma * HIV infection * Co-infection with hepatitis B virus (HBV) * Renal impairment * Pancreatitis * Use of illicit or drugs of abuse * History of alcohol abuse * Presence of clinically significant cardiac arrhythmias * If female, pregnant or lactating

Study Plan

Find out more about all the medication administered in this study, their detailed description and what they involve.
Treatment Groups
Study Objectives
4 intervention groups 

are designated in this study

25% chance 

of being blinded to the placebo group

Treatment Groups
Group I
Active Comparator

Group II
Active Comparator

Group III
Active Comparator

Group IV
Placebo

Study Objectives
Primary Objectives

Study Centers

These are the hospitals, clinics, or research facilities where the trial is being conducted. You can find the location closest to you and its status.
This study has 15 locations
Suspended
Mayo Clinic HospitalPhoenix, United StatesSee the location
Suspended
Scripps ClinicLa Jolla, United States
Suspended
California Pacific Medical CenterSan Francisco, United States
Suspended
University of California, San FranciscoSan Francisco, United States
Completed15 Study Centers