title: Clinical value of on-treatment HCV RNA levels during different sofosbuvir-based antiviral regimens.
abstract: The European Association for the Study of the Liver (EASL) guidelines recommend HCV RNA measurements at specific time points during sofosbuvir(SOF)-therapy. However, it remains unclear, how these results should be interpreted. We aimed to analyze whether on-treatment HCV RNA levels predict relapse comparing the CobasAmpliPrep/CobasTaqMan v2.0 (CAP/CTM) and Abbott RealTime HCV (ART) assays.
  
  
  
  Samples were collected from 298 patients (HCV genotypes; GT1-5) at weeks (w) 0, 1, 2, 4, 8, 12, 16, 20 and 24 during SOF-based therapy at two university clinics and tested for HCV RNA level by CAP/CTM and ART. Patients were treated with SOF/ribavirin (RBV) 12/24 w (n=99), pegylated-interferon-alfa (PegIFN)/SOF/RBV 12 w (n=51), SOF/simeprevir (SMV)±RBV 12 w (n=69) or SOF/daclatasvir±RBV 12/24 w (n=79).
  
  
  
  HCV RNA levels during the first 4weeks of SOF/RBV therapy were significantly lower in GT3 patients who achieved SVR compared with those who relapsed. All GT3 patients with a week 2 result <45IU/ml by CAP/CTM achieved SVR but only 33% of those with ⩾45IU/ml (p=0.0003). Similar results were documented with ART and 60IU/ml as cut-off (SVR: 100% vs. 29%; p=0.0002). In contrast, HCV RNA levels during early treatment phases were not significantly related to relapse in patients treated with other SOF-based regimens. Residual HCV RNA was frequently detected by ART at later stages of therapy. However, SVR rates remained high in these patients. At the end of SOF/SMV±RBV therapy HCV RNA was detectable with ART in 20% of patients, of whom 92% achieved SVR.
  
  
  
  HCV RNA levels assessed at week 2 of SOF/RBV therapy can predict relapse in GT3-patients. Detectable HCV RNA results at later stages during SOF-based therapy may occur frequently with the more sensitive ART. However, this should not lead to treatment extension.
  
  
  
  We analyzed the predictive value of hepatitis C virus (HCV) RNA levels measured at different time points for treatment efficacy. We found that the level of HCV RNA measured at week 2 of antiviral therapy can be used to predict treatment success in patients with HCV genotype 3 infection treated with sofosbuvir and ribavirin but not in patients treated with other sofosbuvir-based regimens. Low level HCV RNA is frequently detected by the RealTime HCV assay during later stages of antiviral therapy. However, this is not associated with reoccurrence of HCV RNA after the end of treatment.
authors.affiliation: Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hanover, Germany.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Maasoumy
authors.affiliation: Department of Medicine 1, University Hospital Frankfurt, Frankfurt am Main, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Vermehren
authors.affiliation: Department of Medicine 1, University Hospital Frankfurt, Frankfurt am Main, Germany.
authors.forename: Martin-Walter
authors.initials: MW
authors.lastname: Welker
authors.affiliation: Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hanover, Germany.
authors.forename: Birgit
authors.initials: B
authors.lastname: Bremer
authors.affiliation: Department of Medicine 1, University Hospital Frankfurt, Frankfurt am Main, Germany.
authors.forename: Dany
authors.initials: D
authors.lastname: Perner
authors.affiliation: Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hanover, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Höner Zu Siederdissen
authors.affiliation: Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hanover, Germany.
authors.forename: Katja
authors.initials: K
authors.lastname: Deterding
authors.affiliation: Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hanover, Germany.
authors.forename: Patrick
authors.initials: P
authors.lastname: Lehmann
authors.affiliation: Abbott Molecular, Des Plaines, IL, USA.
authors.forename: Gavin
authors.initials: G
authors.lastname: Cloherty
authors.affiliation: Abbott GmbH & Co. KG, Wiesbaden, Germany.
authors.forename: Birgit
authors.initials: B
authors.lastname: Reinhardt
authors.affiliation: National Reference Center for Viral Hepatitis B, C and D, Department of Virology, Hôpital Henri Mondor, Université Paris-Est, Créteil, France.
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Pawlotsky
authors.affiliation: Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hanover, Germany.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Manns
authors.affiliation: Department of Medicine 1, University Hospital Frankfurt, Frankfurt am Main, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Zeuzem
authors.affiliation: Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hanover, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Cornberg
authors.affiliation: Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hanover, Germany.
authors.forename: Heiner
authors.initials: H
authors.lastname: Wedemeyer
authors.affiliation: Department of Medicine 1, University Hospital Frankfurt, Frankfurt am Main, Germany. Electronic address: sarrazin@em.uni-frankfurt.de.
authors.forename: Christoph
authors.initials: C
authors.lastname: Sarrazin
mesh_terms: D000998:Antiviral Agents; D005838:Genotype; D016174:Hepacivirus; D006526:Hepatitis C; D006801:Humans; D012328:RNA Viruses; D000069616:Simeprevir; D000069474:Sofosbuvir
chemical_list: D000998:Antiviral Agents; D000069616:Simeprevir; D000069474:Sofosbuvir
keywords: Direct-acting antivirals; HCV RNA; HCV RNA assays; HCV RNA kinetics; HCV RNA quantification; Hepatitis C; Relapse; Response predictors; Sofosbuvir; Sustained virological response