A phase II interferon-free combination study with TMC435 and daclatasvir will evaluate treatment-naive or previous null responder patients with HCV genotype 1a and 1b - The study will include approx. 180 patients and will evaluate a combination of TMC435 and daclatasvir, with or without Ribavirin, in four different cohorts for 12 or 24 weeks of treatment 

 Medivir AB announced that a phase II combination study with the investigational compound TMC435 and Bristol-Myers Squibb's investigational compound daclatasvir will start in July. 

TMC435, a once daily potent NS3/4A protease inhibitor (PI) in phase III clinical development for the treatment of chronic genotype-1 hepatitis C virus (HCV) infection, will be investigated in an interferon free phase II trial in combination with Bristol-Myers Squibb's investigational NS5A replication complex inhibitor, daclatasvir (BMS-790052), also in phase III development.

The purpose of this study is to assess the efficacy and safety of TMC435 and daclatasvir in combination with or without Ribavirin in chronic genotype-1 hepatitis C infected patients who are treatment-naive or null responders to previous Peginterferon alfa/Ribavirin therapy.

Study design

In this open label phase II study the potential to achieve sustained viral response (SVR), 12 (SVR12) and 24 (SVR24) weeks post treatment in treatment-naive and null responder patients infected with HCV genotype 1a and 1b will be evaluated. Patients with advanced liver disease (F3/F4) will be allowed up to approx. 35% of the total treated population.

Cohort one and two will include patients with genotype 1b where TMC435 and daclatasvir will be dosed with or without Ribavirin for 12 weeks with a 36 weeks follow-up or for 24 weeks with a 24 weeks follow-up.

 Cohort three and four will include patients with genotype 1a where TMC435, daclatasvir and Ribavirin will be dosed for 12 or 24 weeks with a 24 weeks post treatment follow-up.