• This is an exploratory study. Effectiveness, viral characteristics, safety and the pharmacokinetic/pharmacodynamic relationship will be studied
  

• Effectiveness, viral characteristics, safety and the pharmacokinetic/pharmacodynamic relationship will be studied
  

Approximately 3% of the world population is infected with Hepatitis C. In about 70% of the cases, this infection becomes chronic. The current standard of care for chronic genotype 1 Hepatitis C infection is 48 weeks of treatment with a so-called "pegylated interferon" and ribavirin. There are two approved treatments commercially available (Pegylated interferon alfa 2a + ribavirin and Pegylated interferon alfa 2b + ribavirin).The purpose of the study is to explore the safety and effectiveness of the different treatment combinations and to study the amount of telaprevir in the blood. Two different doses of telaprevir (750 mg every 8 hours, and 1125 mg every 12 hours) will be studied in combination with standard therapy for chronic Hepatitis C Virus infection. Patients will be randomised to one of 4 treatment groups: Telaprevir 750 mg every 8 hours + Pegylated interferon alfa 2a + ribavirin; Telaprevir 750 mg every 8 hours + Pegylated interferon alfa 2b + ribavirin; Telaprevir 1125 mg every 12 hours + Pegylated interferon alfa 2a + ribavirin; Telaprevir 1125 mg every 12 hours + Pegylated interferon alfa 2b + ribavirin. Telaprevir will be administered for 12 weeks in combination with 24 weeks of the standard therapy. In case of sub-optimal response, standard therapy will be extended to 48 weeks. In case of insufficient response, all treatment will be stopped. The study involves frequent visits to the clinic to assess the safety and effectiveness of the treatment (daily visits until Day 4 of treatment; then weekly until Week 4; then every 2 weeks until Week 16; and then every 4 weeks until Week 24). After the end of treatment, all patiens will be followed for 24 weeks to assess the safety and effectiveness of the treatment and to study the virus in the blood. If no virus can be detected in the blood at the end of the treatment, but it becomes detectable at any time during the follow-up period thereafter (this is called a "relapse"), then the patient will be followed for another 24 weeks after the relapse was noted.

There will be 4 treatment groups: 12 weeks of telaprevir 750 mg every 8 hours + 24 weeks of Pegylated interferon alfa 2a + ribavirin; 12 weeks of telaprevir 750 mg every 8 hours + 24 weeks of Pegylated interferon alfa 2b + ribavirin; 12 weeks of telaprevir 1125 mg every 12 hours + 24 weeks of Pegylated interferon alfa 2a + ribavirin; 12 weeks of telaprevir 1125 mg every 12 hours + 24 weeks Pegylated interferon alfa 2b + ribavirin.