Peginterferon Alfa-2b or Alfa-2a with Ribavirin for Treatment of Hepatitis C Infection

Background Treatment guidelines recommend the use of peginterferon alfa-2b or peginterferon alfa-2a in combination with ribavirin for chronic hepatitis C virus (HCV) infection. However, these regimens have not been adequately compared. Methods At 118 sites, patients who had HCV genotype 1 infection and who had not previously been treated were randomly assigned to undergo 48 weeks of treatment with one of three regimens: peginterferon alfa-2b at a standard dose of 1.5 μg per kilogram of body weight per week or a low dose of 1.0 μg per kilogram per week, plus ribavirin at a dose of 800 to 1400 mg per day, or peginterferon alfa-2a at a dose of 180 μg per week plus ribavirin at a dose of 1000 to 1200 mg per day. We compared the rate of sustained virologic response and the safety and adverse-event profiles between the peginterferon alfa-2b regimens and between the standard-dose peginterferon alfa- 2b regimen and the peginterferon alfa-2a regimen. Results Among 3070 patients, rates of sustained virologic response were similar among the regimens: 39.8% with standard-dose peginterferon alfa-2b, 38.0% with low-dose peginterferon alfa-2b, and 40.9% with peginterferon alfa-2a (P=0.20 for standarddose vs. low-dose peginterferon alfa-2b; P=0.57 for standard-dose peginterferon alfa-2b vs. peginterferon alfa-2a). Estimated differences in response rates were 1.8% (95% confidence interval [CI], −2.3 to 6.0) between standard-dose and low-dose peginterferon alfa-2b and −1.1% (95% CI, −5.3 to 3.0) between standard-dose peginterferon alfa-2b and peginterferon alfa-2a. Relapse rates were 23.5% (95% CI, 19.9 to 27.2) for standard-dose peginterferon alfa-2b, 20.0% (95% CI, 16.4 to 23.6) for lowdose peginterferon alfa-2b, and 31.5% (95% CI, 27.9 to 35.2) for peginterferon alfa- 2a. The safety profile was similar among the three groups; serious adverse events were observed in 8.6 to 11.7% of patients. Among the patients with undetectable HCV RNA levels at treatment weeks 4 and 12, a sustained virologic response was achieved in 86.2% and 78.7%, respectively. Conclusions In patients infected with HCV genotype 1, the rates of sustained virologic response and tolerability did not differ significantly between the two available peginterferon– ribavirin regimens or between the two doses of peginterferon alfa-2b. (ClinicalTrials. gov number, NCT00081770.

Randomized trial of peginterferon alfa-2b and ribavirin for 48 or 72 weeks in patients with hepatitis C virus genotype 1 and slow virologic response.

International audienceUNLABELLED: The benefit of extending treatment duration with peginterferon (PEG-IFN) and ribavirin (RBV) from 48 weeks to 72 weeks for patients with chronic hepatitis C genotype 1 infection has not been well established. In this prospective, international, open-label, randomized, multicenter study, 1,428 treatment-naïve patients from 133 centers were treated with PEG-IFN alfa-2b (1.5 μg/kg/week) plus RBV (800-1,400 mg/day). Patients with detectable hepatitis C virus (HCV) RNA and a ≥2-log(10) drop in HCV RNA levels at week 12 (slow responders) were randomized 1:1 to receive 48 weeks (n = 86) or 72 weeks (n = 73) of treatment. Sustained virologic response (SVR) rates were 43% in slow responders treated for 48 weeks and 48% in slow responders treated for 72 weeks (P = 0.644). Relapse rates were similar in slow responders treated for 48 or 72 weeks (47% versus 33%, P = 0.169). The safety profile was similar in both treatment arms; serious adverse events leading to discontinuation of treatment were observed in 3.5% of slow responders treated for 48 weeks and 8.2% of those treated for 72 weeks. Among slow responders with a <2-log drop in HCV RNA at week 8, SVR was 39% in the 72-week arm and 19% in the 48-week arm. CONCLUSION: These data suggest that 48 weeks of therapy with PEG-IFN alfa-2b plus RBV (800-1,400 mg/day) should remain a standard-of-care treatment for treatment-naïve G1 slow responders

Predictors of consent to pharmacogenomics testing in the IDEAL study

IntroductionPharmacogenomic testing is important in developing individualized therapeutic approaches. In the phase 3 IDEAL (Individualized Dosing to Assess Optimal Pegylated Interferon Therapy) clinical trial, a subset of patients receiving peginterferon and ribavirin for treatment of chronic hepatitis C agreed to provide blood samples for genetic testing. Genome-wide association studies subsequently identified associations between IL28B polymorphism and sustained virologic response, and ITPA polymorphism and ribavirin-associated anemia.ObjectiveTo characterize the groups of patients who accepted or declined pharmacogenomic testing in the IDEAL study.MethodsClinical and demographic factors and treatment outcomes were compared at all sites that had approved pharmacogenomic testing. Differences between patients who consented to and declined pharmacogenomic testing were analyzed using Student's t-test and (2)-test.ResultsIn total, 109 of 118 sites participated in the pharmacogenomic substudy, and 1674 of 2949 (57%) patients enrolled at these sites consented to pharmacogenomic testing. More patients treated in academic medical centers than in community centers (60 vs. 52%,

Refinement of Stopping Rules During Treatment of Hepatitis C Genotype 1 Infection With Boceprevir and Peginterferon/Ribavirin

In comparison with peginterferon/ribavirin alone, boceprevir with peginterferon/ribavirin significantly improves sustained virological response (SVR) rates in patients with chronic hepatitis C virus (HCV) genotype 1 infections, but treatment failure remains a significant problem. Using phase 3 trial databases, we sought to develop stopping rules for patients destined to fail boceprevir-based combination therapy in order to minimize drug toxicity, resistance, and costs in the face of ultimate futility. Exploratory post hoc analyses using data from the Serine Protease Inhibitor Therapy 2 (SPRINT-2) study (treatment-naive patients) and the Retreatment With HCV Serine Protease Inhibitor Boceprevir and Pegintron/Rebetol 2 (RESPOND-2) study (treatment-experienced patients) were undertaken to determine whether protocol-specified stopping rules (detectable HCV RNA at week 24 for SPRINT-2 and at week 12 for RESPOND-2) could be refined and harmonized. In SPRINT-2, a week 12 rule with an HCV RNA cutoff of 100 IU/mL would have discontinued therapy in 65 of 195 failures (sensitivity 5 33%) without sacrificing a single SVR among 475 successes (specificity 5 100%). Viral variants emerged after week 12 in 36 of the 49 evaluable patients (73%) who would have discontinued at week 12 using a 100 IU/mL stopping rule. In RESPOND-2, five of six patients with week 12 HCV RNA levels between the lower limit of detection (9.3 IU/mL) and the lower limit of quantification (25 IU/mL) who continued therapy despite the protocol-stipulated futility rule achieved SVR; one additional patient with a week 12 HCV RNA level of 148 IU/mL also continued therapy, had undetectable HCV RNA at week 16, and attained SVR. Conclusion: Although a stopping rule of detectable HCV RNA at week 12 would have forfeited some SVR cases, week 12 HCV RNA levels 100 IU/mL almost universally predicted a failure to achieve SVR in both treatment-naive and treatment-experienced patients. In boceprevir recipients, the combination of 2 stopping rules-an HCV RNA level 100 IU/mL at week 12 and detectable HCV RNA at week 24-maximized the early discontinuation of futile therapy and minimized premature treatment discontinuation. (HEPATOLOGY 2012;56:567-575) C ombination therapy with peginterferon alfa/ ribavirin (P/R) has been the standard approach to the management of chronic hepatitis C virus (HCV) infections for the last decade. Sustained virological response (SVR) rates of 54% to 56% were achieved in the pivotal trials of Abbreviations: HCV, hepatitis C virus; LLD, lower limit of detection; LLQ, lower limit of quantification; P/R, pegintron alfa/ribavirin; RESPOND-2, Retreatment With HCV Serine Protease Inhibitor Boceprevir and Pegintron/Rebetol 2; SPRINT-2, Serine Protease Inhibitor Therapy 2; SVR, sustained virological response. From th