Patients were screened at 31 sites in Australia, France, Spain, the United Kingdom, and the United States (including Puerto Rico). Patients at least 18 years old (no upper limit) were eligible if they had chronic HCV GT1, 4, 5, or 6 infection with HCV RNA >1,000 IU/mL at screening. HCV genotype and subtype were assessed with the Versant HCV Genotype Inno LiPA Assay, version 2.0 or higher, or Sanger sequencing of the NS5B region if indeterminate initially by LiPA. Patients had to have past VF failure to an approved DAA‐containing regimen that included an NS5A inhibitor (limited to DCV, LDV, or ombitasvir [OBV]) and/or NS3/4A PI (limited to paritaprevir, simeprevir [SIM], asunaprevir, telaprevir, or boceprevir). NS5B inhibitors (SOF or dasabuvir [DSV]) could have been present in any past treatment regimen, and patients could have had failure to multiple past regimens. Patients with sequential exposures to multiple regimens (i.e., PI‐containing regimen followed by an NS5A inhibitor‐containing regimen) were considered to have past experience to both. Median time since patients' last previous VF is reported in the http://onlinelibrary.wiley.com/doi/10.1002/hep.29671/suppinfo. Patients could have compensated cirrhosis (Child‐Pugh score of 6 or less) or no cirrhosis. Absence of cirrhosis (e.g., METAVIR score ≤3, Ishak score ≤4) was determined by liver biopsy within 24 months before (or during) screening, transient elastography (TE; FibroScan) score of <12.5 kilopascals (kPa) within 6 months before (or during) screening, or a screening FibroTest score of ≤0.48 and an aspartate aminotransferase (AST) to platelet ratio index (APRI) <1. Presence of cirrhosis was determined by past histological diagnosis of cirrhosis on liver biopsy (e.g., METAVIR [or equivalent] score of >3 [including 3/4], Ishak score of >4), past TE (FibroScan) score of ≥14.6 kPa, or a screening FibroTest score of ≥0.75 and an APRI >2. Patients with indeterminate FibroScan were required to have liver biopsy and indeterminate FibroTest or conflicting FibroTest, and APRI scores were required to have TE or liver biopsy to determine cirrhosis status. Complete inclusion and exclusion criteria are included in http://onlinelibrary.wiley.com/doi/10.1002/hep.29671/suppinfo.