Clinical significance of residual viremia detected by two real-time PCR assays for response-guided therapy of HCV genotype 1 infection.

BACKGROUND & AIMS: The duration of current standard dual and protease inhibitor-based triple therapies for chronic hepatitis C is determined by assessment of early viral kinetics. Little is known about differences between HCV RNA assays for the use in response guided therapy. METHODS: HCV RNA was assessed by two widely used real-time PCR-based assays, Cobas Ampliprep/Cobas TaqMan (CAP), and Real-Time HCV (ART) in 903 samples of hepatitis C genotype 1 patients treated with dual (n=169) or telaprevir-based triple therapy (n=164) in three European countries. RESULTS: Overall, CAP and ART were in excellent agreement for the determination of HCV-RNA concentrations (mean difference 0.21 log10 IU/ml). For treatment-naïve patients treated with peginterferon-alfa and ribavirin a lower rate of undetectable HCV-RNA at week 4 (RVR) was observed for ART (9%) vs. CAP (16%). Although 11/27 (41%) of patients with shortened treatment (24weeks) had detectable HCV-RNA <12IU/ml by ART at week 4 none of these patients experienced virologic relapse after treatment cessation. In patients who received triple therapy, 67% and 37% had undetectable HCV-RNA at week 4 by CAP and ART, respectively. However, 18/31 (58%) eligible patients for shortened treatment based on CAP had detectable HCV-RNA by ART at week 4. Again, relapse was not observed in these patients. CONCLUSIONS: Lower rates of undetectable HCV-RNA at week 4 were observed with ART compared to CAP in patients treated with dual and triple therapies. For ART, detectable <12IU/ml HCV-RNA levels at week 4 may be sufficient as part of the criteria used for selecting patients who receive a shortened treatment regimen.

HVR-1 heterogeneity during treatment with telaprevir with or without pegylated interferon alfa-2a.

BACKGROUND: The extensive heterogeneity of the hypervariable region-1 (HVR-1) of hepatitis C virus (HCV) evidences the high genetic flexibility of HCV and was shown to be associated with virologic response to interferon-α-based therapies. However, the evolution of HVR-1 heterogeneity during treatment with directly acting antivirals has not been studied. METHODS: Clonal sequence analysis of HVR-1 quasispecies in the serum of patients who were treated with telaprevir (3 × 750 mg/day) alone, telaprevir plus pegylated interferon-α-2a (pegIFN-α-2a), or pegIFN-α-2a plus placebo for 14 days was performed. HVR-1 heterogeneity, expressed as Shannon complexity and Hamming distance, was analyzed with virologic response and with the emergence of variants associated with resistance to telaprevir. RESULTS: HVR-1 heterogeneity at baseline was not associated with response to telaprevir-based therapy (Shannon complexity 0.34 vs. 0.55, p = 0.38; Hamming distance 0.15 vs. 0.23, p = 0.51; for patients with or without viral breakthrough, respectively). No significant changes in HVR-1 complexity were observed from baseline to day 4 of therapy in patients in whom a continued decline in HCV RNA was observed (Shannon complexity = 0.55 vs. 0.51, p = 0.67; Hamming distance = 0.23 vs. 0.25, p = 0.81, respectively). This was similar in patients with viral breakthrough associated with telaprevir-resistant variants (Shannon complexity = 0.34 vs. 0.42, p = 0.68; Hamming distance = 0.15 vs. 0.2, p = 0.50, at baseline and day 4, respectively). CONCLUSIONS: Baseline and on-treatment HVR-1 heterogeneity are not associated with early viral response to telaprevir-based therapy.

Predictive value of interferon-lambda gene polymorphisms for treatment response in chronic hepatitis C.

BACKGROUND: IL28B gene polymorphism is the best baseline predictor of response to interferon alfa-based antiviral therapies in chronic hepatitis C. Recently, a new IFN-L4 polymorphism was identified as first potential functional variant for induction of IL28B expression. Individualization of interferon alfa-based therapies based on a combination of IL28B/IFN-L4 polymorphisms may help to optimize virologic outcome and economic resources. METHODS: Optimization of treatment outcome prediction was assessed by combination of different IL28B and IFN-L4 polymorphisms in patients with chronic HCV genotype 1 (n = 385), 2/3 (n = 267), and 4 (n = 220) infection treated with pegylated interferon alfa (PEG-IFN) and ribavirin with (n = 79) or without telaprevir. Healthy people from Germany (n = 283) and Egypt (n = 96) served as controls. RESULTS: Frequencies of beneficial IL28B rs12979860 C/C genotypes were lower in HCV genotype 1/4 infected patients in comparison to controls (20-35% vs. 46-47%) this was also true for ss469415590 TT/TT (20-35% vs. 45-47%). Single interferon-lambda SNPs (rs12979860, rs8099917, ss469415590) correlated with sustained virologic response (SVR) in genotype 1, 3, and 4 infected patients while no association was observed for genotype 2. Interestingly, in genotype 3 infected patients, best SVR prediction was based on IFN-L4 genotype. Prediction of SVR with high accuracy (71-96%) was possible in genotype 1, 2, 3 and 4 infected patients who received PEG-IFN/ribavirin combination therapy by selection of beneficial IL28B rs12979860 C/C and/or ss469415590 TT/TT genotypes (p<0.001). For triple therapy with first generation protease inhibitors (PIs) (boceprevir, telaprevir) prediction of high SVR (90%) rates was based on the presence of at least one beneficial genotype of the 3 IFN-lambda SNPs. CONCLUSION: IFN-L4 seems to be the best single predictor of SVR in genotype 3 infected patients. For optimized prediction of SVR by treatment with dual combination or first generation PI triple therapies, grouping of interferon-lambda haplotypes may be helpful with positive predictive values of 71-96%.

Vitamin D levels vary during antiviral treatment but are unable to predict treatment outcome in HCV genotype 1 infected patients.

BACKGROUND: Different parameters have been determined for prediction of treatment outcome in hepatitis c virus genotype 1 infected patients undergoing pegylated interferon, ribavirin combination therapy. Results on the importance of vitamin D levels are conflicting. In the present study, a comprehensive analysis of vitamin D levels before and during therapy together with single nucleotide polymorphisms involved in vitamin D metabolism in the context of other known treatment predictors has been performed. METHODS: In a well characterized prospective cohort of 398 genotype 1 infected patients treated with pegylated interferon-α and ribavirin for 24-72 weeks (INDIV-2 study) 25-OH-vitamin D levels and different single nucleotide polymorphisms were analyzed together with known biochemical parameters for a correlation with virologic treatment outcome. RESULTS: Fluctuations of more than 5 (10) ng/ml in 25-OH-vitamin D-levels have been observed in 66 (39) % of patients during the course of antiviral therapy and neither pretreatment nor under treatment 25-OH-vitamin D-levels were associated with treatment outcome. The DHCR7-TT-polymorphism within the 7-dehydrocholesterol-reductase showed a significant association (P = 0.031) to sustained viral response in univariate analysis. Among numerous further parameters analyzed we found that age (OR = 1.028, CI = 1.002-1.056, P = 0.035), cholesterol (OR = 0.983, CI = 0.975-0.991, P<0.001), ferritin (OR = 1.002, CI = 1.000-1.004, P = 0.033), gGT (OR = 1.467, CI = 1.073-2.006, P = 0.016) and IL28B-genotype (OR = 2.442, CI = 1.271-4.695, P = 0.007) constituted the strongest predictors of treatment response. CONCLUSIONS: While 25-OH-vitamin D-levels levels show considerable variations during the long-lasting course of antiviral therapy they do not show any significant association to treatment outcome in genotype 1 infected patients.

Investigation of viral escape mutations within HCV p7 during treatment with amantadine in patients with chronic hepatitis C.

BACKGROUND: Combination of several direct-acting antiviral agents will be necessary to overcome viral resistance in interferon-free treatment regimens for chronic HCV infection. HCV p7 inhibitors may be part of such combination regimens. Understanding why amantadine, despite showing inhibition of HCV p7 in vitro, appears ineffective in clinical trials, may help in the design of novel HCV p7 inhibitors. So far it is unknown whether viral escape mutations within HCV p7 explain the ineffectiveness of amantadine in vivo. METHODS: Pretreatment HCV p7 was directly sequenced in 157 consecutive patients with chronic HCV genotype 1b infection who had been treated with amantadine/placebo plus pegylated interferon (PEG-IFN)-α2a/ribavirin within a multicentre clinical trial. Triple therapy was preceded by 2 weeks of amantadine/placebo monotherapy. In nine patients, clonal sequencing was performed at baseline and after 2 weeks of amantadine/placebo monotherapy. RESULTS: Changes of the relative frequency of amino acid substitutions by ≥20% between pretreatment and week 2 of monotherapy were considered potential resistance mutations if they were only found in patients receiving amantadine but not in patients receiving placebo. Seven substitutions fulfilling these criteria were identified in the subset of patients with clonal sequencing. However, none of these substitutions were associated with treatment outcome in the complete cohort of patients receiving triple therapy with amantadine. CONCLUSIONS: Potential viral escape mutations within HCV p7 do not seem to play a major role for treatment response to antiviral therapy with amantadine and PEG-IFN-α2a/ribavirin in patients with chronic HCV genotype 1b infection.

Clinical utility of the ARCHITECT HCV Ag assay for early treatment monitoring in patients with chronic hepatitis C genotype 1 infection.

BACKGROUND: Virologic response-monitoring is essential for determining therapy duration in patients with chronic hepatitis C virus (HCV) infection. This is usually performed using highly sensitive HCV-RNA assays. However, HCV-RNA assays are time-consuming, expensive and require highly trained personnel. Quantitative determination of HCV core-antigen (HCVAg) levels may be used to supplement treatment monitoring. OBJECTIVES: The clinical utility of the ARCHITECT HCV Ag assay (Abbott Diagnostics) for response-guided therapy was investigated. STUDY DESIGN: We analyzed serum from 160 patients with HCV genotype 1 infection who had been treated with peg-interferon alfa-2b/ribavirin. HCVAg levels were determined at baseline, weeks 1, 2, 4 and 12. HCVAg levels were compared to those obtained with HCV-RNA assays: VERSANT HCV Quantitative 3.0 (bDNA) and Qualitative (TMA, both Siemens Healthcare) assay and the Abbott RealTime HCV assay (ART; Abbott Diagnostics). RESULTS: Baseline HCVAg levels correlated well with HCV-RNA as assessed by bDNA (r=0.91; p<0.0001) and ART (r=0.92; p<0.0001), respectively. Patients with undetectable HCVAg levels at week 1 had a 90.9% probability (positive predictive value) to achieve a rapid virologic response (HCV-RNA undetectable at week 4) based on TMA and 86.4% based on ART, respectively. Patients with less than 1 log(10) reduction in HCVAg between baseline and week 12 had a 90% probability (negative predictive value) to achieve a nonresponse (<2 log(10) decline in HCV-RNA between baseline and week 12) based on bDNA and 100% based on ART, respectively. CONCLUSIONS: Determination of HCVAg may be useful for antiviral response-monitoring in patients with HCV genotype 1 infection.

Impact of ribavirin on HCV replicon RNA decline during treatment with interferon-α and the protease inhibitors boceprevir or telaprevir.

BACKGROUND: Ribavirin increases early and sustained virological response rates in patients chronically infected with HCV who receive pegylated interferon-α and novel HCV protease inhibitors. METHODS: To better characterize antiviral efficacies of these upcoming therapies, Huh7 cells harbouring a subgenomic HCV replicon system were cultivated with various doses and combinations of ribavirin, interferon-α, and the protease inhibitors boceprevir and telaprevir. Antiviral efficacy parameters were estimated from HCV RNA decay, and synergistic effects of combination therapies were analysed with the Bliss independency model. RESULTS: Single-drug antiviral activities showed dose-dependent HCV RNA reductions in replicon cells (50% inhibitory concentration of 386.16 µM, 81.67 IU, 0.44 µM and 0.81 µM after 48 h for ribavirin, interferon-α, boceprevir and telaprevir, respectively). For the dual combination of ribavirin with either boceprevir or telaprevir, no deviation from additivity was observed whereas the reduction of HCV RNA was synergistic for ribavirin with interferon-α (P<0.001). Triple combinations with ribavirin, interferon-α and protease inhibitors showed the most profound HCV RNA decay. CONCLUSIONS: The beneficial in vitro antiviral effect of ribavirin with interferon-α and novel HCV protease inhibitors demonstrates that ribavirin may be required as an antiviral backbone in the near future.

Screening for IL28B gene variants identifies predictors of hepatitis C therapy success.

BACKGROUND: Recent research has shown that genetic variation in the IL28B gene predicts both chronicity of HCV infection and sustained virological response (SVR) to antiviral standard therapy. Because HCV affects 170 million people worldwide and is a leading cause of cirrhosis and hepatocellular carcinoma, screening for prognostic factors in routine clinical practice requires rapid and reliable assays. METHODS: The frequencies of gene polymorphisms IL28B rs8099917, rs12979860 and rs12980275 were investigated in two cohorts of 89 and 187 unrelated HCV-infected Caucasian patients and 195 non-infected participants. This was carried out by means of newly developed sensitive Pyrosequencing™ screening assays. RESULTS: The minor alleles were more frequent in patients (n=276) than in controls (n=195), with odds ratios (recessive hereditary model) of 2.2-11.6, indicating a moderate to large genotype effect size. The positive predictive values of the minor alleles for chronicity of HCV infection were 68.3%, 64.8% and 65.8% for rs8099917, rs12979860 and rs12980275, respectively. The minor alleles were also more frequent in patients who had a non-SVR (n=49) than in SVR patients (n=40), with odds ratios of 1.1-3.5 showing a small to moderate genotype effect size. The positive predictive values for non-SVR were 56.9%, 79.2% and 74% for rs8099917, rs12979860 and rs12980275, respectively. CONCLUSIONS: With the screening for IL28B polymorphisms rs12980275, rs8099917 and rs12979860, which are associated with HCV chronicity and with reduced SVR rates, an important prognostic factor of the therapy of chronic hepatitis C can be easily diagnosed.