Fourati S, et al. - Given that hepatitis C virus (HCV) subtype 4r has been suggested to be less responsive to direct-acting antiviral (DAA) drug treatment than other genotype 4 subtypes, researchers focused on frequent antiviral treatment failures in patients infected with hepatitis C virus genotype 4, subtype 4r by analyzing data of 537 DAA-treated patients who experienced a virological failure in France between 2015 and 2018. Data reported that the lower rates of SVR in patients infected with subtype 4r were associated with the frequent preexistence at treatment baseline and subsequent selection by DAA treatment of both NS5A and NS5B S282 resistance-associated substitutions (RASs). Results of this study suggested that these patients should be identified and receive a triple DAA combination regimen as first-line treatment. It was noted that the prevalence of S282C/T RASs at treatment failure was significantly higher in patients infected with genotype 4r than with other genotypes, including other subtypes of genotype 4.