In this phase 3 trial we evaluated the efficacy and safety of the interferon-free combination of ABT-450 with ritonavir ( ABT-450 / r ) , ombitasvir ( also known as ABT-267 ) , dasabuvir ( also known as ABT-333 ) , and ribavirin for the retreatment of HCV in patients who were previously treated with peginterferon-ribavirin .