Short Article: Retreatment of Chronic Hepatitis C Virus Infection after Unsuccessful Therapy with All-Oral Direct-Acting Antiviral Regimens: a Real-Life Experience.

OBJECTIVE:Few real-life data are available on the retreatment of patients who failed direct-acting antiviral (DAA)-regimens. We reported the outcome of retreatment with approved DAA regimens in a real-life cohort of patients who previously failed an all-oral DAAs combination and we analyzed the association with resistance substitutions (RASs) performed at the time of virological failure.AIM AND METHODS:Next-generation sequencing of the NS3, NS5A, and NS5B regions was performed by Illumina deep sequencing. The sequence reads were analyzed by an in-house pipeline.RESULTS:Of the 16/759 (2%) patients who failed to achieve a sustained virological response at 12 weeks to all-oral DAAs from December 2014 to January 2016, 10 were retreated with licensed DAAs regimens. In all the patients, retreatment was followed by sustained virological response at 12 weeks. Baseline NS3-RASs before retreatment were observed in two patients who failed a sofosbuvir/simeprevir regimen: D168V RAS was detected in a genotype-4 patient, whereas the complex RAS-pattern Q80K, I170V, R155K, D168E was observed in a genotype-1a patient. Only one of the two patients who previously failed ombitasvir, paritaprevir/ritonavir, and dasabuvir underwent RAS analysis at relapse and showed baseline NS5A RAS (M28V) before retreatment.CONCLUSION:These real-life findings indicated a high efficacy of sofosbuvir+NS5A-inihbitors in retreating NS3-experienced patients and also NS5A-experienced patients by using a 24-week course ribavirin-containing regimen. The relevance of hepatitis C virus resistance testing before retreatment remains to be better defined to guide the choice of the new regimen before retreatment in DAA-experienced patients.