title: Prevalence of end of treatment RNA-positive/sustained viral response in HCV patients treated with sofosbuvir combination therapies.
abstract: BACKGROUND
  Some chronic hepatitis C virus (HCV), genotype 1 infected patients treated with direct antiviral agents (DAAs) remain viremic at end of treatment (EOT+), yet go on to achieve sustained virological response 12 weeks after completion of therapy (SVR12). The incidence of EOT+/SVR in patients with genotype 1 and other genotypes, as well as whether such patients achieve SVR24remain in question. The aims of this study were to evaluate the frequency and durability of EOT+/SVR12&24and other response categories in HCV genotype 1, 2, or 3 infected patients treated with DAA in clinical practice.
  
  
  METHODS
  Data from patients treated with all oral sofosbuvir-based regimens at a university hepatology practice by 1 July 2015 were reviewed retrospectively. Responses were categorized based on virus levels during and post DAA treatment. HCV RNA levels were measured by Abbott RealTime HCV (ART) or by Roche CobasTaqMan v2.0 (RCTM) assays.
  
  
  RESULTS
  The study population included 89 patients. Participants were 62% genotype 1, 19% genotype 2 and 19% genotype 3, 54% cirrhotic and 46% treatment-experienced. A total of 45 received sofosbuvir-simeprevir, 38 sofosbuvir-ribavirin and 6 sofosbuvir-ledipasvir. The SVR12rate was 82%. A total of 5 patients (6%), all with genotype 1, had EOT+ by ART assay and each achieved SVR12&24.
  
  
  CONCLUSIONS
  A total of 9% of genotype 1 patients (6% overall) treated with DAAs were EOT+ by ART and all EOT+ cases achieved SVR24. EOT+/SVR was not observed with genotype 2 or 3 or by the RCTM assay. In patients treated with DAAs, EOT+ by the ART assay does not indicate treatment failure.
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Medicine, University of Florida Health, 4555 Emerson St. Ste. 300, Jacksonville, FL 32207, USA.
authors.forename: Miguel
authors.initials: M
authors.lastname: Malespin
authors.affiliation: Program for Experimental and Theoretical Modeling, Division of Hepatology, Department of Medicine, Loyola University Medical Center, Maywood, IL, USA.
authors.forename: Tamara
authors.initials: T
authors.lastname: Benyashvili
authors.affiliation: Program for Experimental and Theoretical Modeling, Division of Hepatology, Department of Medicine, Loyola University Medical Center, Maywood, IL, USA.
authors.forename: Susan L
authors.initials: SL
authors.lastname: Uprichard
authors.affiliation: Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, NM, USA.
authors.forename: Alan S
authors.initials: AS
authors.lastname: Perelson
authors.affiliation: Program for Experimental and Theoretical Modeling, Division of Hepatology, Department of Medicine, Loyola University Medical Center, Maywood, IL, USA.
authors.forename: Harel
authors.initials: H
authors.lastname: Dahari
authors.affiliation: Program for Experimental and Theoretical Modeling, Division of Hepatology, Department of Medicine, Loyola University Medical Center, Maywood, IL, USA.
authors.forename: Scott J
authors.initials: SJ
authors.lastname: Cotler
keywords: HCV; SVR; direct antiviral agents; end of treatment response