hepatitis c National Center for Biotechnology Information NCBI NLM MEDLINE humans pubmed abstract nih national institutes of health national library of medicine treatment outcome research support non-u.s. gov't Clinical Trial Phase III Multicenter Study Viral Genotype drug resistance drug therapy combination genetic variation high-throughput nucleotide sequencing hepacivirus / genetics* chronic / drug therapy* antiviral agents / administration & dosage* treatment failure hepacivirus / classification sustained virologic response sofosbuvir / administration & dosage* stefan zeuzem chronic / virology* heterocyclic compounds hepacivirus / drug effects* pmid:29221887 doi:10.1016/j.jhep.2017.11.032 christophe hezode nancy reau carbamates / administration & dosage* 4 or more rings / administration & dosage* viral nonstructural proteins / antagonists & inhibitors viral nonstructural proteins / genetics