Vaniprevir plus peginterferon alfa-2b and ribavirin in treatment-experienced Japanese patients with hepatitis C virus genotype 1 (GT1b) infection: Phase 3 studies.

BACKGROUND AND AIM: Vaniprevir is a macrocyclic hepatitis C virus (HCV) non-structural (NS)3/4A protease inhibitor. The objective of these phase 3 multicenter, open-label trials was to evaluate the safety and efficacy of vaniprevir + peginterferon alfa-2b + ribavirin (PR) in Japanese patients with HCV genotype (GT)1 infection who had previously failed treatment with interferon-based regimens. METHODS: Japanese patients with chronic HCV GT1 were enrolled. In PN044, patients with previous relapse or virologic breakthrough were randomized to vaniprevir (300 mg twice daily) + PR for 12 weeks followed by PR for another 12 weeks (12-week arm) or vaniprevir + PR for 24 weeks (24-week arm). In PN045, patients with previous partial/null response received vaniprevir + PR for 24 weeks. The primary endpoint was sustained virologic response at 24 weeks after completing treatment (SVR24 ). RESULTS: In PN044 (n = 51), SVR24 was 92.0% and 96.2% in the 12- and 24-week arms, respectively. In PN045 (n = 42), SVR24 was 61.9% in all patients and 55.2% in previous null responders. In both studies, vaniprevir + PR was generally safe and well tolerated; the majority of adverse events were mild/moderate and included pyrexia, decreased hemoglobin, headache, nausea, pruritus, and decreased platelet count. Polymorphisms in the HCV NS3 gene at baseline (Y56, Q80, and V170) did not impact treatment outcome. Virologic failure was principally associated with the on-treatment emergence of R155 or D168 mutations. CONCLUSIONS: Vaniprevir + PR is an effective, well-tolerated treatment for Japanese patients with HCV GT1 infection who failed previous interferon-based treatment. ClinicalTrials.gov Identifier NCT01405937 and NCT01405560 (Protocols PN044 and PN045).

The combination of MK-5172, peginterferon, and ribavirin is effective in treatment-naive patients with hepatitis C virus genotype 1 infection without cirrhosis.

BACKGROUND & AIMS: MK-5172 is an inhibitor of the hepatitis C virus (HCV) nonstructural protein 3/4A protease; MK-5172 is taken once daily and has a higher potency and barrier to resistance than licensed protease inhibitors. We investigated the efficacy and tolerability of MK-5172 with peginterferon and ribavirin (PR) in treatment-naive patients with chronic HCV genotype 1 infection without cirrhosis. METHODS: We performed a multicenter, double-blind, randomized, active-controlled, dose-ranging, response-guided therapy study. A total of 332 patients received MK-5172 (100, 200, 400, or 800 mg) once daily for 12 weeks in combination with PR. Patients in the MK-5172 groups received PR for an additional 12 or 36 weeks, based on response at week 4. Patients in the control group (n = 66) received a combination of boceprevir and PR, dosed in accordance with boceprevir's US product circular. RESULTS: At 24 weeks after the end of therapy, sustained virologic responses were achieved in 89%, 93%, 91%, and 86% of the patients in the groups given the combination of PR and MK-5172 (100, 200, 400, or 800 mg), respectively, vs 61% of controls. In the MK-5172 group receiving 100 mg, 91% of patients had undetectable levels of HCV RNA at week 4 and qualified for the short duration of therapy. The combination of MK-5172 and PR generally was well tolerated. Transient increases in transaminase levels were noted in the MK-5172 groups given 400 and 800 mg, at higher frequencies than in the MK-5172 groups given 100 or 200 mg, or control groups. CONCLUSIONS: Once-daily MK-5172 (100 mg) with PR for 24 or 48 weeks was highly effective and well tolerated among treatment-naive patients with HCV genotype 1 infection without cirrhosis. Studies are underway to evaluate interferon-free MK-5172-based regimens. ClinicalTrials.gov number: NCT01353911.

A phase 2B study of MK-7009 (vaniprevir) in patients with genotype 1 HCV infection who have failed previous pegylated interferon and ribavirin treatment.

BACKGROUND & AIMS: MK-7009 (vaniprevir) is a non-covalent competitive inhibitor of the hepatitis C virus (HCV) NS3/4A protease. This report presents the primary analysis results (safety and sustained viral response) of a phase 2b study of MK-7009 given in combination with peginterferon (PegIFN) alfa2a 180 µg weekly and ribavirin (RBV) 1000-1200 mg/day, for 24-48 weeks to non-cirrhotic patients who have failed previous PegIFN and RBV treatment. METHODS: We present results of a randomized, placebo-controlled, double-blind study of MK-7009 administered for 24-48 weeks in combination with PegIFN and RBV in 4 regimens to at least 40 patients per arm. Stratification by prior response to PegIFN and RBV was as follows: null response, partial response, breakthrough and relapse. HCV RNA was determined by Roche Cobas Taqman with a lower limit of detection (LLoD) of 10 IU/ml and a lower limit of quantification (LLoQ) of 25 IU/ml. RESULTS: SVR24 in patients on MK-7009+PegIFN and ribavirin (P/R) was statistically superior to placebo+P/R in all treatment groups (p<0.001). MK-7009 at 300 mg b.i.d. and 600 mg b.i.d. is generally well tolerated for use for up to 48 weeks of therapy. Patients in MK-7009 regimens had higher rates of gastrointestinal adverse events as compared to control (mostly mild to moderate). There were no significant differences in rates of anemia and rash between the MK-7009 regimens and control. CONCLUSIONS: In conclusion, patients treated with MK-7009 plus P/R experienced significant improvement in SVR compared to P/R control in a population of GT 1 experienced patients.

Vaniprevir plus peginterferon alfa-2b and ribavirin in treatment-naive Japanese patients with hepatitis C virus genotype 1 infection: a randomized phase III study.

BACKGROUND: Vaniprevir is a potent macrocyclic hepatitis C virus (HCV) nonstructural protein 3/4A protease inhibitor. This phase III study evaluated the safety and efficacy of vaniprevir in combination with peginterferon alfa-2b and ribavirin (PR) for 24 weeks compared with PR alone for 48 weeks in treatment-naive Japanese patients with HCV genotype 1 infection. METHODS: Treatment-naive Japanese patients with HCV genotype 1 infection were randomly assigned to receive vaniprevir (300 mg twice daily) plus PR for 12 weeks then PR alone for 12 weeks, vaniprevir (300 mg twice daily) plus PR for 24 weeks, or PR alone for 48 weeks. The primary end point was sustained virologic response 24 weeks after completion of treatment (SVR24). RESULTS: In total, 294 patients were randomly assigned to receive treatment. Most patients had HCV genotype 1b infection (98 %, 288 of 294 patients). SVR24 was achieved in 83.7, 84.5, and 55.1 % of the patients in the vaniprevir 12-week, vaniprevir 24-week, and control arms, respectively. The difference in SVR24 rates between each vaniprevir arm and the control arm was statistically significant (p < 0.001 for both). Relapse was commoner in the control arm (29.5 %) than in the vaniprevir arms (8.6 % and 10.5 % for the 12-week and 24-week arms, respectively). Commonly reported adverse events were generally similar across treatment arms, with the exception of an increase in the incidence of gastrointestinal adverse events such as nausea, diarrhea, and vomiting in patients receiving vaniprevir. These events were considered manageable. CONCLUSION: Vaniprevir is a valuable addition to the therapeutic options available to Japanese patients with HCV genotype 1 infection who are eligible for interferon-based treatment. CLINICALTRIALS. GOV IDENTIFIER: NCT01370642.

Vaniprevir plus peginterferon alfa-2a and ribavirin in treatment-experienced Japanese patients with hepatitis C virus genotype 1 infection: a randomized phase II study.

BACKGROUND: Vaniprevir (MK-7009) is a hepatitis C virus (HCV) non-structural 3/4a protease inhibitor which significantly increases virologic response rates in HCV genotype (GT) 1-infected patients when added to peginterferon and ribavirin (PR). METHODS: This was a phase II, multicenter, double-blind, randomized, dose-ranging study in Japanese patients with HCV GT1 infection and previous relapse. Patients received twice daily vaniprevir 100, 300, or 600 mg, or placebo plus PR for 4 weeks then PR alone for 2 weeks. Further treatment with PR was continued up to a maximum of 72 weeks. The primary endpoint was rapid virologic response (RVR; undetectable HCV RNA at treatment week 4). RESULTS: Ninety patients completed 4 weeks of vaniprevir/placebo plus PR. Rates of RVR were significantly higher with vaniprevir compared with placebo (86, 95, and 76 % in the vaniprevir 100-, 300-, and 600-mg arms versus 20 % with control; p<0.001 for all comparisons). Rates of SVR, an exploratory analysis, in the vaniprevir 100-, 300-, 600-mg, and control arms were 95, 100, 100, and 72 %, respectively. No patient had virologic breakthrough or non-response while receiving vaniprevir. There were no serious adverse events (AEs) or discontinuations due to an AE during vaniprevir treatment. Diarrhea and nausea were more common with vaniprevir 600 mg than control or lower vaniprevir doses. CONCLUSION: The addition of vaniprevir to PR was associated with an increase in RVR and SVR. Combined with a generally safe and well-tolerated profile, these data supported the further evaluation of vaniprevir in Japanese patients with HCV GT1 infection (#NCT00880763).

Emergence of resistance-associated variants after failed triple therapy with vaniprevir in treatment-experienced non-cirrhotic patients with hepatitis C-genotype 1 infection: a population and clonal analysis.

BACKGROUND: Vaniprevir with P/R improved SVR rates over P/R alone in treatment-experienced patients with chronic HCV-genotype 1 infection, but treatment failure presents therapeutic challenges. We identified RAVs from non-cirrhotic patients failing to achieve SVR on vaniprevir-containing regimens from a dose/duration-ranging trial of triple-combination therapy. METHODS: Using population analysis, resistance sequencing was performed on all baseline samples and on samples at virologic failure in the vaniprevir arms. Longitudinal clonal analyses were performed on viral isolates from six vaniprevir recipients experiencing breakthrough viremia. RESULTS: Baseline RAVs were detected in two patients subsequently experiencing virologic failure. At virologic failure, the majority of RAVs had substitutions at R155, A156, or D168. Clonal analyses identified novel double/triple variants emerging with continuing vaniprevir dosing. CONCLUSIONS: RAVs were predominantly observed at R155, A156, and/or D168 during virologic failure on vaniprevir/P/R. Double/triple RAVs were identified in patients remaining viremic on triple therapy, suggesting evolution of resistance under selective pressure.