Evaluating the Safety of ITX 5061 in Treatment-Naive Hepatitis C (HCV)-Infected Adults

HCV is a serious health concern and can lead to cirrhosis, liver cancer, and liver failure.
Currently, HCV is treated with pegylated interferon and ribavirin, but these medications are
not always effective and may have harmful side effects. ITX 5061 is a new medication that
has been developed to treat HCV. This study will take place in three parts—Parts A, B, and
C. Each part of the study will enroll participants for a different period of time, and
within each part of the study, participants will receive varying amounts of ITX 5061. If ITX
5061 is found to be unsafe in any part of the study, the subsequent parts of the study will
not occur. The purpose of this study is to evaluate the safety of different doses of ITX
5061 and determine the amount of time that is needed for ITX 5061 to safely lower the amount
of HCV in the blood.

This study will enroll people with HCV who are HIV-uninfected. Participants will enroll in
one of three parts of the study. They will be randomly assigned to receive ITX 5061 or
placebo once a day for 3 days in Part A, for 14 days in Part B, or for 28 days in Part C.
Within Parts A, B, and C, participants will receive either 150 mg, 75, mg, or 25 mg of ITX
5061. At a baseline study visit, participants will have a physical exam and blood and urine
collection. All participants will receive their assigned medication at this visit.
Participants in Part A will return for study visits on the 2 days after the baseline visit.
During these study visits, participants will undergo a physical exam and will have blood
collected several times over an 8-hour period. Participants in Part B of the study will
attend study visits 1, 2, 3, 7, 10, and 13 days after the baseline visit. Participants in
Part C of the study will attend study visits 1, 2, 3, 7, 10, 14, 21, and 27 days after the
baseline visit. Participants in Parts B and C will undergo similar study procedures as
participants in Part A. Throughout the study, participants will record their medication
usage in a diary.

All participants will attend a study visit the day after they receive their last medication
dose. In addition, participants in Part A will attend study visits 9 and 16 days after the
baseline visit, participants in Part B will attend study visits 20 and 27 days after the
baseline visit, and participants in Part C will attend study visits 34 and 41 days after the
baseline visit. At each of these follow-up visits, participants will have a physical exam
and a blood and urine collection.