Boceprevir for chronic HCV genotype 1 infection in patients with prior treatment failure to peginterferon/ribavirin, including prior null response

Background & Aims Boceprevir with peginterferon/ribavirin (BOC/PR) leads to significantly higher sustained virological response (SVR) rates in patients with chronic hepatitis C and partial response or relapse after prior treatment with peginterferon/ribavirin. We studied the efficacy of BOC/PR in patients with prior treatment failure, including those with a null response (<2-log₁₀ decline in HCV RNA), to peginterferon/ribavirin. Methods Patients in the control arms of boceprevir Phase 2/3 studies who did not achieve SVR were re-treated with BOC/PR for up to 44 weeks. Patients enrolling >2 weeks after end-of-treatment in the prior study received PR for 4 weeks before adding boceprevir. Results Of 168 patients enrolled, four discontinued from the PR lead-in and 164 received BOC/PR. Baseline viral load was >800,000 IU/ml in 77% of patients; 62% had HCV genotype 1a, and 10% were cirrhotic. In the ITT analysis (all 168 patients), SVR was achieved in 20 (38%) of 52 patients with prior null response, 57 (67%) of 85 with prior partial response, and 27 (93%) of 29 with prior relapse. In the mITT analysis (164 BOC/PR-treated patients), SVR rates were 41% (20/49), 67% (57/85), and 96% (27/28), respectively. SVR was achieved by 48% of patients with <1-log₁₀ decline in HCV-RNA after lead-in and 76% of those with ≥1-log₁₀ decline or undetectable HCV-RNA after lead-in. The most common adverse events were anemia (49%), fatigue (48%), and dysgeusia (35%); 8% of patients discontinued due to adverse events. Conclusions Re-treatment with BOC/PR improved SVR rates in all patient subgroups, including those with prior null response.