Adherence to assigned dosing regimen and sustained virological response among chronic hepatitis C genotype 1 patients treated with boceprevir plus peginterferon alfa‐2b/ribavirin

Summary 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. Aim 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