& Aims: Interferon-free treatment options are rapidly evolving for patients with chronic hepatitis C virus (HCV) genotype 1b (GT1b) infection with cirrhosis and for nonresponders to prior pegylated interferon and ribavirin therapy. We performed a phase 2b, open-label trial of the combination of ombitasvir (a NS5A replication complex inhibitor), paritaprevir, and ritonavir (an NS3/4A protease inhibitor)—an interferon- and ribavirin-free regimen—in difficult-to-treat patients, including prior null responders and patients with cirrhosis.