Development and persistence of DAA resistance associated mutations in patients failing HCV treatment

Stefania Paolucci, Loretta Fiorina, Bianca Mariani, Viviana Landini, Roberto Gulminetti, Stefano Novati, Renato Maserati, Giorgio Barbarini, Raffaele Bruno, Fausto Baldanti

Research output: Contribution to journalArticlepeer-review


Background: Direct-acting antiviral agents (DAAs) combined with pegylated-interferon (PegIFN) and ribavirin (RBV) are still a standard treatment in patients with genotype 1HCV infection. However, virologic response could be impaired by baseline or early selection of resistant HCV strains. Objectives: The aim of this study was to determine the onset and persistence of resistance-associated mutations (RAMs) in the NS3 and NS5B genes of DAA-naïve patients failing treatment. Study design: Direct sequencing of HCV NS3 was performed in 49 DAA-naïve patients with HCV genotype 1 infection. Results: Eight out of 23 patients (34.7%) failed PegIFN/RBV/telaprevir during the 12-weeks of therapy. Treatment failure was associated with the development of RAMs at amino-acids 36,54,80 and 155 of the HCV protease in 6/8 patients (75%). Among patients treated with PegIFN/RBV/boceprevir treatment, 4/18 (22.2%) failed therapy. Of these, 2 (50%) carried virus strains which developed a RAM at amino-acids 54 and 155. Among HCV strains with RAMs, 7 belonged to genotype 1a and 1 to 1b. Finally, in 6/10 (60%) patients, drug-resistant variants could still be detected for up to 3-7 months after stopping therapy. Conclusions: A higher rate (. p=. 0.49) of treatment failure was observed in patients receiving telaprevir- compared to the boceprevir-based combination. In addition, compared with genotype 1b, genotype 1a was associated with higher rates (. p=. 0.01) of treatment failure due to virus resistant strains.Resistance testing at baseline and during DAA treatment should be taken into consideration when treating patients with new HCV combination therapies.

Original languageEnglish
Pages (from-to)114-118
Number of pages5
JournalJournal of Clinical Virology
Publication statusPublished - Nov 1 2015


  • Drug resistance
  • HCV genotype 1
  • Hepatitis C virus
  • Protease inhibitors
  • Sequencing

ASJC Scopus subject areas

  • Virology
  • Infectious Diseases


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