Inclusion Criteria:

• Male or female patients 18 years old or above
• Patient with French social security or other equivalent health assurance
• Patient with informed consent
• Serologic evidence of chronic hepatitis C by detectable anti-HCV antibodies
• Patient infected by HCV genotype 1, 4, 5 or 6
• Compensated liver disease (Child-Pugh ≤ 6)
• Negative urine or blood pregnancy test (for women of childbearing potential) documented within the 24-hour period prior the enrollment in the study
• All fertile males and females receiving ribavirin must have effective contraception during treatment and during the 6 following months
• Patient naive of treatment with installation of treatment by investigator following criteria for use Peginterferon alfa-2a (Pegasys) and ribavirin (Copegus)

Exclusion Criteria:

• Women with ongoing pregnancy or breast feeding
• Male partner of pregnancy woman
• Minor
• Major protected by French law for biomedical study
• Co-infection by HBV or HIV
• History or other evidence of decompensated liver disease or Child-Pugh score > 6
• Clinical or radiological evidence (abdominal ultrasound, CT scan or MRI) of hepatocellular carcinoma
• IFN or ribavirin at any previous time
• Patient who received an erythropoetin within 2 months before inclusion
• History of epilepsy (during the last 6 months)
• Chronic cardiac insufficiency (stage III or IV in classification from the New York Heart Association [NYHA])
• Not controlled portal hypertension
• Antecedents or risk of venous thrombosis
• Surgery within 3 months before inclusion
• Serum creatinine level >15 mg/mL (130µmol/L)
• Deficiency in vitamin B9 and/or B12 (suspected with macrocytosis > 105 µm3)
• Thrombocytosis (platelets > 500 000/mm3)
• Chronic inflammatory syndrome (CRP > 10 mg/L)
• Deficiency not corrected in iron :
• Ferritin blood level < 10 µg/L Or - Transferrin saturation coefficient < 20 %
• History of neoplasia (except basocellular epithelioma and cervical cancer)
• Contraindications to use epoetin beta or an excipient from molecule to study (urea, polysorbate 20, glycine, leucine, isoleucine, threonine, glutamic acid, phenylalanine, benzoic acid, benzyl alcohol)
• Absence of written informed consent
• Exclusion time for another biomedical study
• Patient with blood concentration of hemoglobin lower or equal to 12 g/dL for male or lower or equal to 11 g/dL for female