Taribavirin Phase 2 Dose Finding Study for the Treatment of Hepatitis C Virus (HCV)
Taribavirin Phase 2 Dose Finding Study for the Treatment of Hepatitis C Virus (HCV)
The objective of the study is to select an optimal dose of taribavirin by comparing the
 efficacy and safety of 3 taribavirin dose levels, 20, 25, and 30 mg/kg/day, versus ribavirin
 800 to 1400 mg/day based on body weight, both administered in combination with peginterferon
 alfa-2b to therapy-naive patients with chronic Hepatitis C Virus (HCV) genotype 1 infection.
The objective of the study is to select an optimal dose of taribavirin by comparing the
 efficacy and safety of 3 taribavirin dose levels, 20, 25, and 30 mg/kg/day, versus ribavirin
 800 mg/day to 1400 mg/day based on subject body weight, with both drugs administered in
 combination with peginterferon alfa-2b to therapy-naive patients with chronic Hepatitis C
 Virus genotype 1 infection.
Subject Inclusion Criteria

 To be eligible for enrollment, patients must meet all of the following criteria:

 1. At least 18 years of age

 2. Diagnosed with compensated chronic HCV genotype 1 infection that has not been treated
 with interferon, peginterferon, ribavirin or any experimental therapy for >28 days

 2a Serum HCV RNA >2000 copies/mL (780 IU/mL) 2b Liver biopsy performed within 3 years prior
 to screening consistent with chronic HCV infection 2c Criteria for compensated HCV
 infection, including normal prothrombin time, serum albumin and bilirubin levels (unless
 due to non-hepatitis factors) and no history or evidence of bleeding esophageal varices,
 ascites, or hepatic encephalopathy

 3 History of alanine aminotransferase (ALT) elevation either within 6 months prior to
 screening, at screening, or on retest 2 weeks after a negative screening test, or
 histologic evidence of HCV infection and a detectable viral load

 4 Platelet count ≥90,000/mm3

 5 Absolute neutrophil count ≥1200/mm3

 6 Hemoglobin ≥12.0 g/dL for females or ≥13.0 g/dL for males

 7 Antinuclear antibody (ANA) titer ≤1:320

 8 Serum creatinine <1.5 mg/dL

 9 HbA1c ≤8.5% for diabetic patients

 10 Normal or adequately controlled TSH on prescription medication

 11 Alpha fetoprotein (AFP) <20 ng/mL or hepatocellular carcinoma ruled out (ultrasound, CT
 or MRI scan) within 6 months prior to the study (Patients with an AFP >20 ng/mL must have
 ongoing hepatocellular carcinoma screening during study as part of the patient's routine
 medical care)

 12 All other clinical laboratory values within normal limits, unless judged not clinically
 significant by the investigator

 13 Sterile or infertile (defined as vasectomy, tubal ligation, postmenopausal, or
 hysterectomy), or willing to use an approved method of double-barrier contraception
 (hormonal plus barrier or barrier plus barrier, eg, diaphragm plus condom) from the time of
 first dose administration until 6 months after the last dose

 14 Capable of understanding instructions, adhering to study schedules and requirements, and
 willing to provided informed consent

 Subject Exclusion Criteria

 Patients who have any of the following during the screening or Day 1 visit are not eligible
 for enrollment in this study:

 1. Positive HIV or HbsAg serology

 2. Severe psychiatric or neuropsychiatric disorders including severe depression, history
 of suicidal ideations or suicide attempt(s). (This would include patients with a
 history of suicidal ideations or suicide attempt(s) that occurred when the patient was
 a minor or many years ago; if the event occurred while under the influence of alcohol
 or drugs; if the suicidal ideations or suicide attempt(s) were connected to a
 traumatic event; if the patient was not hospitalized or treated; if the patient has
 obtained psychiatric clearance for treatment)

 3. History or clinical manifestations of significant metabolic, hematological, pulmonary,
 ischemic or unstable heart disease, gastrointestinal, neurological, renal, urological,
 endocrine, ophthalmologic (including severe retinopathy), or immune mediated disease

 4. History of thalassemia or other hemoglobinopathies (even if the hemoglobin is normal)

 5. Chronic hepatic disease other than hepatitis C

 6. Organ or bone marrow transplant

 7. Chronic (greater than 30 days) use of immunosuppressive medications including steroids
 in doses equivalent to 10 mg of prednisone or higher, 30 days prior to and anytime
 during the course of the study

 8. Female patients who are breast-feeding or have a positive pregnancy test at any time
 during the study

 9. Males whose female partners are pregnant

 10. Patients who have had a malignancy diagnosed and/or treated within the past 5 years,
 except for localized squamous or basal cell cancers treated by local excision

 11. Patients who have participated in a clinical trial and have received an
 investigational drug within 30 days prior to screening

 12. History of alcoholism or drug addiction 1 year prior to screening

 13. The use of methadone, buprenorphine or any similar drug, regardless of the prescribed
 indication or the length of time the patient has been on the drug

 14. Chronic (>4 weeks duration) diarrhea, including irritable bowel disease

 15. Fibrosis score F4 (cirrhosis) based on Metavir or equivalent index

 16. Weight >128 kg or <40 kg

 17. Patients infected with mixed HCV genotypes