The purpose of the study is to demonstrate the noninferiority of Algeron in combination with ribavirin compared to Pegasys in combination with ribavirin in the treatment of chronic hepatitis C.

The course of treatment in both groups shall be 12 weeks, and efficacy analysis, i.e. rate of rapid (after the 4th week) and early (after the 12th week) virologic response will be based on PCR data. For patients with treatment failure after the 12th week the antiviral therapy shall be discontinued. All patients who require further anti-viral treatment will receive a combination treatment with Algeron / Pegasys and ribavirin for another 12 or 36 weeks (depending on the HCV genotype). Sustained virologic response will be assessed 24 weeks after last dose of study treatment.

Inclusion Criteria:

1. Signed informed consent to participate in the study.
2. Chronic HCV infection (genotypes 1а, 1b, 2, 3, 4) with detectable HCV RNA >6 month before the screening visit or abnormal ALT levels for >6 month before the screening visit.
3. Male and female patients, 18 to 70 years of age, inclusive.
4. Body mass index of 18 - 30 kg/m2.
5. Preserved protein synthetic liver function (INR < 1.7, albumin > 35 g/l).
6. No signs of hepatic encephalopathy or abdominal fluid retention according to clinical and ultrasound examination.
7. Fertile patients and their partners agree to use barrier contraception throughout the study treatment and 7 months after it.
8. Patient must have documentation of fibroscan within 1 year before the screening visit or agree to have a fibroscan within the screening period.

Exclusion Criteria:

1. Intolerance to IFN alfa, ribavirin or any components of this preparations confirmed by past medical history.
2. Infection by hepatitis B, A, E virus or HIV (co-infection).
3. Any other documented significant liver disease (drug or alcohol-related cirrhosis, autoimmune hepatitis, hemochromatosis, Wilson's disease, nonalcoholic steatohepatitis, biliary cirrohosis, etc.).
4. Past history of HCV treatment with IFN alfa or pegylated IFN alfa.
5. Administration of injectable and non-injectable interferons and/or some interferon inducers for any indication (other than HCV) for one month before enrollment into the study.
6. Cholestatic hepatitis (level of conjugated bilirubin, alkaline phosphatase, G-GTP exceeding the upper normal level by more than 5 times).
7. Decompensated liver cirrhosis confirmed by laboratory findings (class B, С according to Child-Pugh) or ultrasound examination.
8. Any documented autoimmune diseases (e.g., Crohn's disease, ulcerative colitis, systemic lupus erythematosus, idiopathic thrombocytopenic purpura, scleroderma, autoimmune haemolytic anemia, severe psoriasis).
9. Hemoglobin not lower than low normal level; neutrophils < 1.5 х109/L; platelets < 90 х109/L; creatinin level exceeding the upper normal level by more than 1.5 times, ALT level exceeding the upper normal level by more than 10 times.
10. Documented hemoglobinopathies (e.g., thalassemia major, sickle-cell anemia).
11. Severe depression, schizophrenia, other mental disorders, which from the investigator's point of view are a contraindication for anti-viral treatment.
12. Epilepsy and/or disorder of function of the central nervous system.
13. Abnormal thyroid function (TTH level beyond the normal values).
14. Diagnosed or suspected hepatocellular carcinoma as evidenced by screening alfa-fetoprotein (AFP) of ≥ upper normal level.
15. Antinuclear antibody (ANA) titer ≥1:640 at screening and/or evidence of autoimmune hepatitis on liver biopsy.
16. Malignant neoplasms.
17. Pregnancy, lactation period.
18. Severe comorbidities (for example, severe hypertension, severe coronary heart disease, decompensated diabetes mellitus) that represent a contraindication for anti-viral treatment.
19. Documented rare hereditary diseases, such as intolerance of lactose, sucrose, fructose, lactase deficiency or glucose-galactose malabsorption.
20. Known drug or alcohol abuse or signs of drug/alcohol abuse in present, which from the investigator's point of view are a contraindication for anti-viral treatment or restrict adherence to the treatment regimen.
21. Simultaneous participation in other clinical studies less than 30 days before enrollment into this study or previous participation in this clinical study.