title: Adherence to assigned dosing regimen and sustained virological response among chronic hepatitis C genotype 1 patients treated with boceprevir plus peginterferon alfa-2b/ribavirin.
abstract: BACKGROUND
  Adherence to therapeutic regimens affects the efficacy of peginterferon alfa (P) and ribavirin (R) therapy in patients with chronic hepatitis C virus genotype 1.
  
  
  OBJECTIVE
  To determine if medication adherence impacts efficacy [sustained virological response (SVR)] with triple therapy that includes boceprevir (BOC) plus P/R.
  
  
  METHODS
  Adherence was determined in two Phase 3 clinical studies with BOC: SPRINT-2 (previously untreated patients) and RESPOND-2 (patients who failed previous therapy with P/R). Adherence to the assigned duration of the dosing regimen and adherence to the three times a day (t.d.s.) dosing interval of 7-9 h for BOC were assessed by the recording of data from patients' dosing diaries and by the amount of study drug dispensed and returned.
  
  
  RESULTS
  Most patients (63-71%) adhered to ≥80% of their assigned treatment duration and achieved SVR rates of 86-90%. In contrast, patients who adhered to <80% of their assigned treatment duration achieved SVR rates of 8-32% (P < 0.0001), particularly low in patients who failed previous therapy (SVR = 8-15%). Different rates of adherence (<60% to >80%) to the t.d.s. dosing interval (7-9 h) with BOC did not influence the SVR rates (SVR = 60-83%) with the exception of patients who failed previous treatment and adhered to <60% of the t.d.s. dosing interval with BOC (SVR = 48-50%; P = 0.005).
  
  
  CONCLUSIONS
  The achievement of an SVR is more dependent on adherence to the assigned duration of treatment than adherence to the t.d.s. dosing interval with boceprevir. Adherence to >60% of t.d.s. dosing with boceprevir is important in patients who failed previous therapy.
authors.affiliation: Henry Ford Hospital, Detroit, MI 48202-2689, USA. SGordon3@hfhs.org
authors.forename: S C
authors.initials: SC
authors.lastname: Gordon
authors.forename: E M
authors.initials: EM
authors.lastname: Yoshida
authors.forename: E J
authors.initials: EJ
authors.lastname: Lawitz
authors.forename: B R
authors.initials: BR
authors.lastname: Bacon
authors.forename: M S
authors.initials: MS
authors.lastname: Sulkowski
authors.forename: M
authors.initials: M
authors.lastname: Davis
authors.forename: F
authors.initials: F
authors.lastname: Poordad
authors.forename: J-P
authors.initials: JP
authors.lastname: Bronowicki
authors.forename: R
authors.initials: R
authors.lastname: Esteban
authors.forename: V
authors.initials: V
authors.lastname: Sniukiene
authors.forename: M H
authors.initials: MH
authors.lastname: Burroughs
authors.forename: W
authors.initials: W
authors.lastname: Deng
authors.forename: F J
authors.initials: FJ
authors.lastname: Dutko
authors.forename: C A
authors.initials: CA
authors.lastname: Brass
authors.forename: J K
authors.initials: JK
authors.lastname: Albrecht
authors.forename: K
authors.initials: K
authors.lastname: Rajender Reddy
mesh_terms: D000998:Antiviral Agents / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004359:Drug Therapy, Combination; D005260:Female; D005838:Genotype; D016174:Hepacivirus / Q000235:genetics*; D019698:Hepatitis C, Chronic / Q000188:drug therapy* / Q000235:genetics / Q000821:virology; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000627:therapeutic use*; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D011092:Polyethylene Glycols / Q000627:therapeutic use*; D011392:Proline / Q000031:analogs & derivatives* / Q000627:therapeutic use; D012367:RNA, Viral / Q000235:genetics; D011994:Recombinant Proteins / Q000627:therapeutic use; D012189:Retrospective Studies; D012254:Ribavirin / Q000627:therapeutic use*; D016896:Treatment Outcome; D019562:Viral Load
chemical_list: D000998:Antiviral Agents; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D012367:RNA, Viral; D011994:Recombinant Proteins; D011092:Polyethylene Glycols; D012254:Ribavirin; C512204:N-(3-amino-1-(cyclobutylmethyl)-2,3-dioxopropyl)-3-(2-((((1,1-dimethylethyl)amino)carbonyl)amino)-3,3-dimethyl-1-oxobutyl)-6,6-dimethyl-3-azabicyclo(3.1.0)hexan-2-carboxamide; D011392:Proline; C417083:peginterferon alfa-2b