A Study of Combination Treatment With Peginterferon Alfa-2a (Pegasys) Plus Ribavirin (Copegus) in Participants With Chronic Hepatitis C

• Percentage of participants with sustained viral response [ Time Frame: 24 weeks after the end of treatment (Week 48) ] [ Designated as safety issue: No ]
• Percentage of participants with viral response rate [ Time Frame: Week 12 after the end of treatment (Week 48) ] [ Designated as safety issue: No ]

• Sustained viral response [ Time Frame: End of treatment (weeks 24 or 48) ] [ Designated as safety issue: No ]
• Viral response rate [ Time Frame: At week 12, and at end of treatment (weeks 24 or 48) ] [ Designated as safety issue: No ]

• Drug: Peginterferon alfa-2a
  Peginterferon alfa-2a will be administered at a dose of 180 mcg SC weekly for 48 weeks to participants with genotype 1, 2, 3, 4, 5, 6 and to particpants with HIV co-infection, or for 24 weeks to participants with genotype 2, and 3.
  Other Name: Pegasys
• Drug: Ribavirin
  Ribavirin will be administered at a dose of 1000-1200 mg PO daily for 48 weeks to participants with genotype 1, 4, 5, 6 or 800mg po daily for 24 weeks to participants with genotype 2, and 3.
  Other Name: Copegus

• Experimental: Group A
  Participants with genotype 1, 4, 5 or 6 will receive peginterferon alfa-2a 180 mcg SC qw + ribavirin 1000-1200 mg PO daily (dependent on body weight) for 48 weeks.
  Interventions:

  • Drug: Peginterferon alfa-2a
  • Drug: Ribavirin
• Experimental: Group B
  Participants with with genotype 2 or 3 will receive peginterferon alfa-2a 180 mcg SC qw + ribavirin 800 mg PO daily for 24 weeks.
  Interventions:

  • Drug: Peginterferon alfa-2a
  • Drug: Ribavirin
• Experimental: Group C
  Participants with HIV co-infection will receive peginterferon alfa-2a 180 mcg SC qw + ribavirin 800 mg PO daily for 48 weeks.
  Interventions:

  • Drug: Peginterferon alfa-2a
  • Drug: Ribavirin

Inclusion Criteria:

• Adult participants, greater than or equal to (>=) 18 years of age
• Chronic hepatitis C, with detectable serum hepatitie C virus (HCV) ribonucleic acid (RNA)
• Scheduled for treatment with peginterferon alfa-2a
• Compensated liver disease
• Women in fertile age must be informed about obligation of using adequate contraception during and 6 month post treatment with ribavirin (Copegus®)
• Men with a sexual partner in fertile age must be informed about obligatory contraception preventing pregnancy during the course of treatment with ribavirin (Copegus®)as well as 6 months after treatment cessation
• Female participants in the study must have a negative pregnancy test performed not sooner than within 2 weeks preceding the planned inclusion to the study
• Men with a sexual partner in fertile age must produce a negative result of the partner's pregnancy test performed not sooner than within 2 weeks preceding the planned partner's inclusion to the study

Exclusion Criteria:

• Chronic liver disease other than chronic hepatitis C
• Active hepatitis A virus or hepatitis B virus infection
• Therapy with any systemic antiviral, antineoplastic or immunomodulatory treatment less than or equal to (<=) 6 months prior to first dose of study drug
• Hemoglobin <120 grams per liter (g/L) in female subjects or <130 g/L in male subjects (the result must not be older than 2 weeks prior to inclusion to the study)
• The platelet count <90 x 10^9/liter (the result must not be older than 2 weeks prior to inclusion to the study
• Neutrofils count <1.5 x 10^9/liter (the result must not be older than 2 weeks prior to inclusion to the study)
• Subjects with increased risk of anaemia, or subjects, at risk of serious health problems resulting from anaemia or decrease of hemoglobin (e.g., subjects with serious cardiovascular or cerebrovascular disease)
• History or presence of a serious mental disease, especially depression, which, according to investigator's opinion, does not allow administration of peginterferon alfa-2a (Pegasys®)
• History or presence of a disease consequent to immunodeficiency (e.g., inflammatory diseases of intestine, idiopathic thrombocytopenic purpura, systemic lupus erythematodes, rheumatoid arthritis)