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

• Percentage of Participants With End-of-Treatment Virological Response [ Time Frame: Up to 48 weeks ]
  End-of-treatment virological response is defined as having no HCV virus detectable in the blood immediately after end of treatment.
• Percentage of Participants With Early-Treatment Virological Response [ Time Frame: Up to 12 weeks ]
  Early-treatment virological response is defined as having no HCV virus detectable in the blood or a 2-log (100-fold) decrease in HCV virus concentration in the blood after 12 weeks of study treatment.
• Percentage of Participants With Adverse Events [ Time Frame: Up to 72 weeks ]
  An adverse event is considered any unfavorable and unintended sign, symptom, or disease associated with the use of the study drug, whether or not considered related to the study drug. Preexisting conditions that worsen during the study are reported as adverse events.

• Sustained viral response [ Time Frame: End of treatment (weeks 24 or 48) ]
• Viral response rate [ Time Frame: At week 12, and at end of treatment (weeks 24 or 48) ]

• Drug: Peginterferon alfa-2a
  Peginterferon alfa-2a was administered at a dose of 180 mcg SC weekly for 48 weeks to participants with genotype 1, 4, 5, 6 and to participants with HIV co-infection, or for 24 weeks to participants with genotype 2 and 3.
  Other Name: Pegasys
• Drug: Ribavirin
  Ribavirin was administered at a dose of 1000-1200 mg PO daily for 48 weeks to participants with genotype 1, 4, 5, 6 or 800 mg 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 received 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 genotype 2 or 3 received 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 received 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 at least 18 years of age
• Chronic hepatitis C, with detectable serum hepatitis 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 months 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 participants or <130 g/L in male participants (the result must not be older than 2 weeks prior to inclusion to the study)
• Platelet count <90 x 10^9/liter (the result must not be older than 2 weeks prior to inclusion to the study
• Neutrofil count <1.5 x 10^9/liter (the result must not be older than 2 weeks prior to inclusion to the study)
• Participants with increased risk of anaemia, or participants at risk of serious health problems resulting from anaemia or decrease of hemoglobin (e.g., participants with serious cardiovascular or cerebrovascular disease)
• History or presence of a serious mental disease, especially depression, which, in the 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 erythematosus, rheumatoid arthritis)