Patients with chronic hepatitis C previously treated with pegylated interferon were more likely to achieve sustained virologic response with the addition of boceprevir in a recent study.
In a double-blind trial, 201 patients with chronic HCV genotype 1 were randomly assigned to receive 4 weeks of lead-in treatment with 180 mcg peginterferon alfa-2a once weekly along with daily weight-based ribavirin (PEG2a/R), then either 44 weeks of PEG2a/R with 800 mg boceprevir (BOC/PEG2a/R) (n=134) or placebo (n=67) three times daily. All participants had undergone prior treatment with interferon but had not achieved sustained virologic response (SVR).
Significantly more patients in the treated group achieved SVR at 24 weeks than placebo patients (64% to 66% vs. 21%, P<.0001). SVR rates were higher for treated patients among those who relapsed (70% vs. 28%) or had been nonresponsive (47% vs. 5%) during prior therapy. Among those who had poor treatment response during lead-in, 39% in the treated group experienced SVR compared with 0% in the placebo group. Patients who had good response during lead-in therapy experienced SVR in 71% of cases in the treated group and 25% in the placebo group.
Multivariate analysis indicated that receiving boceprevir (OR=12.0; 95% CI, 4.6-31.1) and prior relapse (OR=4.4; 95% CI, 1.7-11.6) were associated with SVR. A decline in HCV RNA of 1-log10 or more also was independently predictive of SVR, and the addition of treatment response at week 4 to the model increased predictive value (OR=7.9; 95% CI, 2.0-31.6). No evaluated baseline factors were predictive of treatment response.
All participants reported at least one adverse event; but more treated patients discontinued therapy or underwent dose modification because of adverse events (P<.05). Commonly reported events included anemia, neutropenia, dysgeusia, diarrhea and rash, all of which occurred more frequently among treated patients.
“The results of this phase 3 trial show that boceprevir is safe and effective when combined with PEG2a/R in difficult-to-treat patients,” the researchers concluded. “This study and the RESPOND-2 study are the first large phase 3 trials to demonstrate a direct acting antiviral agent may be combined with either of the commercially available peginterferons to significantly increase SVR in patients who failed prior therapy.”
Disclosure: See the study for a full list of relevant disclosures.