The analysis showed a high rate of sustained virologic response (SVR) in patients receiving boceprevir-based combination therapy in this study of 595 treatment-naive patients with chronic hepatitis C virus (HCV) genotype 1.
In a 48-week treatment regimen, the SVR rate at 12 weeks after the end of treatment (SVR 12) was 74% (ITT) in patients who received four weeks of Pegintron (peginterferon alfa-2b) and Rebetol (ribavirin, USP) prior to the addition of boceprevir (800mg TID) (P/R lead-in), compared to 38% for patients in the control group receiving 48-weeks of Pegintron and Rebetol alone.
Patients in the study who received 48-weeks of boceprevir in combination with Pegintron and Rebetol from the beginning of treatment (no P/R lead-in) achieved 66% SVR 12.
In the two 28-week boceprevir arms of the study, SVR at 24 weeks after the end of treatment (SVR 24) was 56% and 55% for patients in the lead-in and no lead-in arms, respectively.
Importantly, for patients who received the Pegintron and Rebetol lead-in and had rapid virologic response (RVR), defined as undetectable virus (HCV-RNA) in plasma after four weeks of boceprevir treatment, SVR (ITT) was 82% in the 28-week regimen and 92% in the 48-week regimen.
Safety data from the study showed that the most common adverse events reported in the boceprevir arms were fatigue, anemia, nausea and headache.