Halfon P, et al. - An examination was entailed in this study of the retreatment with direct-acting antivirals (DAA), based on the baseline nonstructural protein 5A (NS5A) resistance-associated substitutions (RASs) after the failure of first-line DAA-based therapy. Herein, the retreatment was discovered to be effective (96% SVR). It was determined that in prospective studies, dual or triple therapy regimens could exhibit similar results with shorter treatment duration.