Induction pegylated interferon alfa-2a and high dose ribavirin do not increase SVR in heavy patients with HCV genotype 1 and high viral loads

Role of Ribavirin in the Era of Direct-Acting Antiviral Therapies of Chronic Hepatitis C

BACKGROUND

The efficacy of adding ribavirin (RBV) to direct antivirals (DAAs) in HCV treatment is still debatable, with allegations of insecure profiles.

OBJECTIVES

To evaluate safety and efficacy of RBV in the era of DAAs in chronic HCV Egyptian patients.

METHODS

In this cohort retrospective study, data of 847 HCV patients treated with different regimens of DAAs with or without RBV were recruited between June 2017 and September 2018. Cases were categorized into five groups: non-cirrhotic (318), compensated (196), decompensated liver cirrhosis (53), post liver transplantation (30), and 250 treatment experienced patients. All patients' demographics and laboratory characteristics were evaluated at baseline, week_{4, 12, 24} of treatment. Ribavirin was prescribed or banned outside international guideline recommendations of HCV treatment in cases assembled from the private sector.Results: No statistically significant difference between RBV and non-RBV treated patients was documented regarding SVR₁₂ (97.2%, 97.8%) respectively in the whole cohort (p 0.509). On grouping, adding RBV was only significant in the treatment experienced patients (96.8%, 85% in RBV and non-RBV regimens respectively) (p 0.001). Adding RBV to DAA regimens was generally associated with modest adverse events particularly anemia (8.5%), and hepatic decompensation (jaundice and ascites) (0.3%). Bilirubin, INR, and platelet counts all were found to be the most independent predictors of SVR achievement by multivariate analysis (p ≤ 0.05).Conclusion: RBV may still have an augmenting role in treatment experienced patients; permitting effectual shortening of therapy particularly in patients with cirrhosis, with modest side and adverse consequences.

Factors Affecting the Virological Response Among Chronic Hepatitis C Virus Patients in Yemen

Hepatitis C virus (HCV) infection is increasingly seen as a major public health problem, threat, and concern worldwide. In Yemen about 1.7% of the population is infected with chronic hepatitis C. This study aimed to detect the predictors for response to pegylated interferon and ribavirin (Peg-IFN/RBV) in chronic HCV Yemeni patients. The study was conducted on 100 patients with chronic HCV who received Peg-IFN/RBV in the 48th Military Hospital in Sana'a Yemen, from 2011 to 2013. All patients were subjected to complete history taking, thorough clinical examinations, routine laboratory investigation, and abdominal ultrasonography. The HCV RNA was assessed at week 72 of treatment to detect whether the patient achieved sustained virological response (SVR). The SVR was achieved in 64% of the samples. Age above 40, Khat chewing, and obesity were the sociodemographic factors that predict good response for Peg-IFN/RBV combined therapy. Platelet count, alpha feto-protein (AFP), aspartate transaminase (AST), and alanine transaminase (ALT) levels were the basic laboratory investigations that gave favorable response. Significant predictors of sustained response included: older than 40 years (OR = 0.136, P = 0.042), Khat chewer (OR = 0.016, P = 0.008), body mass index (BMI) (OR = 0.055, P = 0.029) and increase in fasting blood glucose (OR = 0.925, P = 0.004), alkaline phosphatase (OR = 0.969, P = 0.001), total and bilirubin (OR = 0.058, P = 0.017), AST (OR = 1.033, P = 0.002), and albumin (OR = 6.490, P = 0.021). Studying the independent variables of response, we revealed that male gender, BMI, ALT >40, AFP >10, viremia >600, and hemoglobin and thyroid stimulating hormone (TSH) levels are variables associated with failure of end of treatment response (ETR) and SVR.

Dose-escalation study evaluating pegylated interferon alpha-2a in patients with cutaneous T-cell lymphoma

BACKGROUND

This open-label, multicenter, dose-escalation study evaluated the safety, tolerability, and efficacy of subcutaneous pegylated (40 kD) interferon α-2a (PEG-IFN α-2a) in patients with cutaneous T-cell lymphoma (CTCL).

PATIENTS AND METHODS

PEG-IFN α-2a was administered subcutaneously at 180 (n = 4), 270 (n = 6), or 360 μg (n = 3) once weekly for 12 weeks. Efficacy was assessed by the proportion of patients with complete response (CR) or partial response (PR).

RESULTS

PEG-IFN α-2a was generally well tolerated, with a moderate number of reductions or withholding of doses because of adverse events (AEs) (25% (n = 1), 66% (n = 4), and 0% (n = 0) in the 180-, 270-, and 360-μg/week groups, respectively). The only dose-limiting toxicity was a grade 3 elevation of liver enzymes in the 270-μg dose group. The most common AEs were fatigue, acute flu-like symptoms, and hepatic toxicity. The major response rate (CR or PR) was 50% in the 180-μg group (CR, 50%; PR, 0%), 83% in the 270-μg group (CR, 67%; PR, 17%), and 66% in the 360-μg group (CR, 33%; PR, 33%).

CONCLUSION

PEG-IFN α-2a at doses up to 360 μg once weekly was well tolerated in patients with CTCL up to the highest dose group and showed good response rates. Due to their good tolerance even in high doses, they might be an option for patients not tolerating standard IFN-α preparations. However, for this purpose and to evaluate comparability between standard and PEG-IFN larger clinical trials are needed, alone and in combination with oral photochemotherapy (PUVA).

Impact of Safety-Related Dose Reductions or Discontinuations on Sustained Virologic Response in HCV-Infected Patients: Results from the GUARD-C Cohort

BACKGROUND

Despite the introduction of direct-acting antiviral agents for chronic hepatitis C virus (HCV) infection, peginterferon alfa/ribavirin remains relevant in many resource-constrained settings. The non-randomized GUARD-C cohort investigated baseline predictors of safety-related dose reductions or discontinuations (sr-RD) and their impact on sustained virologic response (SVR) in patients receiving peginterferon alfa/ribavirin in routine practice.

METHODS

A total of 3181 HCV-mono-infected treatment-naive patients were assigned to 24 or 48 weeks of peginterferon alfa/ribavirin by their physician. Patients were categorized by time-to-first sr-RD (Week 4/12). Detailed analyses of the impact of sr-RD on SVR24 (HCV RNA <50 IU/mL) were conducted in 951 Caucasian, noncirrhotic genotype (G)1 patients assigned to peginterferon alfa-2a/ribavirin for 48 weeks. The probability of SVR24 was identified by a baseline scoring system (range: 0-9 points) on which scores of 5 to 9 and <5 represent high and low probability of SVR24, respectively.

RESULTS

SVR24 rates were 46.1% (754/1634), 77.1% (279/362), 68.0% (514/756), and 51.3% (203/396), respectively, in G1, 2, 3, and 4 patients. Overall, 16.9% and 21.8% patients experienced ≥1 sr-RD for peginterferon alfa and ribavirin, respectively. Among Caucasian noncirrhotic G1 patients: female sex, lower body mass index, pre-existing cardiovascular/pulmonary disease, and low hematological indices were prognostic factors of sr-RD; SVR24 was lower in patients with ≥1 vs. no sr-RD by Week 4 (37.9% vs. 54.4%; P = 0.0046) and Week 12 (41.7% vs. 55.3%; P = 0.0016); sr-RD by Week 4/12 significantly reduced SVR24 in patients with scores <5 but not ≥5.

CONCLUSIONS

In conclusion, sr-RD to peginterferon alfa-2a/ribavirin significantly impacts on SVR24 rates in treatment-naive G1 noncirrhotic Caucasian patients. Baseline characteristics can help select patients with a high probability of SVR24 and a low probability of sr-RD with peginterferon alfa-2a/ribavirin.

DAUPHINE: a randomized phase II study of danoprevir/ritonavir plus peginterferon alpha-2a/ribavirin in HCV genotypes 1 or 4

BACKGROUND & AIMS

Danoprevir is a hepatitis C virus (HCV) protease inhibitor with activity against genotypes (G)1/G4, which is maintained at lower doses by ritonavir-boosting. We report results of a large, randomized, active-controlled phase IIb study of ritonavir-boosted danoprevir (danoprevir/r) plus peginterferon alpha-2a/ribavirin (P/R) in treatment-naive patients with HCV G1/4 infection.

METHODS

Treatment-naive patients with HCV G1/4 infection were randomized to twice-daily danoprevir/r 200/100 mg (A, n = 92); 100/100 mg (B, n = 93); or 50/100 mg (C, n = 94) plus P/R for 24 weeks; twice-daily danoprevir/r 100/100 mg (D, n = 94) plus P/R for 12 or 24 weeks; or P/R alone (E, n = 44) for 48 weeks. Patients in the response-guided therapy arm (D) with an extended rapid virological response (eRVR2: HCV RNA <15 IU/ml during Weeks 2-10) stopped all therapy at Week 12; non-eRVR2 patients continued all treatment to Week 24. The primary efficacy endpoint was sustained the virological response (SVR24: HCV RNA <15 IU/ml after 24 weeks of untreated follow-up).

RESULTS

SVR24 rates in Arms A, B, C, D and E were 89.1%, 78.5%, 66.0%, 69.1% and 36.4%, respectively, in the overall population; 83.6%, 69.6%, 60.3%, 59.2% and 38.5% in G1a-infected patients, 96.6%, 93.1%, 73.1%, 78.4% and 28.6% in G1b-infected patients and 100%, 87.5%, 100%, 100% and 66.7% in G4-infected patients. Danoprevir/r plus P/R was generally well tolerated compared with P/R alone. There was a higher incidence of serious adverse events in danoprevir-treatment arms, but most were associated with P/R.

CONCLUSIONS

The combination of danoprevir/r plus P/R is efficacious in treatment-naïve patients with HCV genotype 1 or 4 infection.

Neutrophil-to-lymphocyte ratio as a predictor of response to peginterferon plus ribavirin therapy for chronic hepatitis C

We aimed to determine whether neutrophil-to-lymphocyte ratio (NLR) could be a predictor of antiviral response in chronic hepatitis C patients. A total of 602 consecutive patients (genotype 1, n = 263; genotype 2, n = 297; others/unknown, n = 42) receiving response-guided therapy with peginterferon plus ribavirin were recruited. NLR was related to clinical and virological features and to treatment outcome. Rapid virological response (RVR) and sustained virological response (SVR) were achieved in 436 (73%) and 458 (76%) of the patients, respectively. Higher NLR (≥1.42) was found to be associated with higher prevalence of DM (P = 0.039) and higher hepatitis C viral load (P = 0.002) and white cell count (P < 0.001). NLR was significantly lower in patients with RVR and SVR compared to those without (P = 0.032 and 0.034, resp.). However, NLR was not an independent factor by multivariate analysis. In the subgroup analysis, higher NLR (≥1.42) (odds ratio, 0.494, P = 0.038) was an independent poor predictor of SVR in genotype 2 patients but was not in genotype 1 patients. In conclusion, NLR is a simple and easily accessible marker to predict response to peginterferon plus ribavirin therapy for chronic hepatitis C genotype 2.

A tool for selecting patients with a high probability of sustained virological response to peginterferon alfa-2a (40kD)/ribavirin

BACKGROUND & AIMS

Pretreatment identification of patients likely to achieve a sustained virological response (SVR) with peginterferon alfa-2a/ribavirin would be useful for individualizing treatment choices. The aim of this analysis was to devise a simple scoring system to identify patients with high probability of achieving an SVR with peginterferon alfa-2a/ribavirin.

METHODS

Using data from 2109 Caucasian treatment-naive hepatitis C virus (HCV) genotype 1 mono-infected patients from the PROPHESYS cohorts, the relationship between favourable baseline characteristics and SVR was explored using generalized additive model analysis, and a scoring system was devised to predict SVR.

RESULTS

Points were assigned for: age (years) (≤35: 2; >35, ≤45: 1; >45: 0); body mass index (kg/m(2)) (≤20: 2; >20, ≤22: 1; >22: 0); HCV RNA (IU/ml) (≤100,000: 3; >100,000-400,000: 2; >400,000-800,000: 1; >800,000: 0); platelets (>150 ×10(9)/l: 1; ≤150 ×10(9)/l: 0); alanine aminotransferase [×upper limit of normal (ULN)] (>3: 1; ≤3: 0); serum aspartate aminotransferase (×ULN) (≤1: 1; >1: 0). 1029, 698 and 382 patients had scores of 0-2, 3-4 and ≥5, respectively, among whom SVR rates were 35.0, 54.9 and 76.7%. SVR in patients with scores ≥5 and undetectable HCV RNA by week 4 was 86.7%. The score was tested against two databases of patients who received peginterferon alfa-2a/ribavirin in other clinical trials; similar high SVR rates in patients with scores ≥5 were reported.

CONCLUSIONS

The scoring system can reliably identify treatment-naive HCV genotype 1 mono-infected Caucasian patients who have a high probability of achieving an SVR with peginterferon alfa-2a/ribavirin and will be particularly useful where protease inhibitors are not readily available.

Persistent hepatitis C virus infection impairs ribavirin antiviral activity through clathrin-mediated trafficking of equilibrative nucleoside transporter 1

Ribavirin (RBV) continues to be an important component of interferon-free hepatitis C treatment regimens, as RBV alone does not inhibit hepatitis C virus (HCV) replication effectively; the reason for this ineffectiveness has not been established. In this study, we investigated the RBV resistance mechanism using a persistently HCV-infected cell culture system. The antiviral activity of RBV against HCV was progressively impaired in the persistently infected culture, whereas interferon lambda 1 (IFN-λ1), a type III IFN, showed a strong antiviral response and induced viral clearance. We found that HCV replication in persistently infected cultures induces an autophagy response that impairs RBV uptake by preventing the expression of equilibrative nucleoside transporter 1 (ENT1). The Huh-7.5 cell line treated with an autophagy inducer, Torin 1, downregulated membrane expression of ENT1 and terminated RBV uptake. In contrast, the autophagy inhibitors hydroxychloroquine (HCQ), 3-methyladenine (3-MA), and bafilomycin A1 (BafA1) prevented ENT1 degradation and enhanced RBV antiviral activity. The HCV-induced autophagy response, as well as treatment with Torin 1, degrades clathrin heavy chain expression in a hepatoma cell line. Reduced expression of the clathrin heavy chain by HCV prevents ENT1 recycling to the plasma membrane and forces ENT1 to the lysosome for degradation. This study provides a potential mechanism for the impairment of RBV antiviral activity in persistently HCV-infected cell cultures and suggests that inhibition of the HCV-induced autophagy response could be used as a strategy for improving RBV antiviral activity against HCV infection.

IMPORTANCE

The results from this work will allow a review of the competing theories of antiviral therapy development in the field of HCV virology. Ribavirin (RBV) remains an important component of interferon-free hepatitis C treatment regimens. The reason why RBV alone does not inhibit HCV replication effectively has not been established. This study provides a potential mechanism for why RBV antiviral activity is impaired in persistently HCV-infected cell cultures and suggests that inhibition of the HCV-induced autophagy response could be used as a strategy to increase RBV antiviral activity against HCV infection. Therefore, it is anticipated that this work would generate a great deal of interest, not only among virologists but also among the general public.

Impact of the peginterferon-α 2a and ribavirin plasma levels on viral kinetics and sustained virological response in genotype 1 HCV/HIV-co-infected patients with the unfavourable non-CC IL28B genotypes

Studies on the association between the peginterferon-α and ribavirin levels and sustained virological response (SVR) have shown yielded conflicting results, but most of them were performed before the influence of IL28B polymorphisms was known. Our aim was to assess the effects of peginterferon-α 2a and ribavirin plasma levels on viral kinetics and SVR in hepatitis C virus genotype 1 HCV-1/HIV-co-infected patients according to IL28B genotype. This was a cohort study of HCV-1/HIV-co-infected patients who were HCV-treatment naïve and for whom the efficacy of peginterferon-α 2a plus ribavirin was evaluated by per-protocol analysis. The peginterferon-α 2a and ribavirin levels were measured by ELISA and HPLC-UV, respectively. The relationships among host and viral factors, the trough drugs levels and virological responses were analysed by multivariate regression analyses. A total of 131 Caucasian patients were included (cirrhosis:38.9%). Overall, SVR rate was 39.6%. In patients with CC IL28B genotype, SVR was related neither to peginterferon-α 2a nor to ribavirin plasma levels, while higher levels of both drugs were the only variables independently associated with SVR in individuals with CT/TT IL28B genotypes (OR, 5.02; CI95 , 1.45-17.1; P = 0.001 and 4.0; CI95 , 1.08-14.7; P = 0.038, respectively). Moreover, faster viral declines were observed in CT/TT patients when pegIFN-α 2a and ribavirin plasma levels were greater than 3400 pg/mL and 1.6 μg/mL, respectively. In contrast to the results for CC patients, the results in patients carrying the unfavourable CT/TT IL28B genotypes showed that plasma levels of both drugs have significant effects on viral kinetics and SVR.

HCV infection selectively impairs type I but not type III IFN signaling

A stable and persistent Hepatitis C virus (HCV) replication cell culture model was developed to examine clearance of viral replication during long-term treatment using interferon-α (IFN-α), IFN-λ, and ribavirin (RBV). Persistently HCV-infected cell culture exhibited an impaired antiviral response to IFN-α+RBV combination treatment, whereas IFN-λ treatment produced a strong and sustained antiviral response that cleared HCV replication. HCV replication in persistently infected cells induced chronic endoplasmic reticulum (ER) stress and an autophagy response that selectively down-regulated the functional IFN-α receptor-1 chain of type I, but not type II (IFN-γ) or type III (IFN-λ) IFN receptors. Down-regulation of IFN-α receptor-1 resulted in defective JAK-STAT signaling, impaired STAT phosphorylation, and impaired nuclear translocation of STAT. Furthermore, HCV replication impaired RBV uptake, because of reduced expression of the nucleoside transporters ENT1 and CNT1. Silencing ER stress and the autophagy response using chemical inhibitors or siRNA additively inhibited HCV replication and induced viral clearance by the IFN-α+RBV combination treatment. These results indicate that HCV induces ER stress and that the autophagy response selectively impairs type I (but not type III) IFN signaling, which explains why IFN-λ (but not IFN-α) produced a sustained antiviral response against HCV. The results also indicate that inhibition of ER stress and of the autophagy response overcomes IFN-α+RBV resistance mechanisms associated with HCV infection.

Emerging therapeutic targets for hepatitis C virus infection

Therapy for hepatitis C virus (HCV) is a rapidly evolving field wherein traditional treatment with the nonspecific antiviral agents pegylated interferon (IFN)-alfa and ribavirin has been and will continue to be supplanted by combinations of targeted therapies against HCV with and without concomitant pegylated IFN and/or ribavirin, resulting in markedly superior rates of viral clearance. Exhaustive study of HCV structure and replication through the development of in vitro systems has enabled the development of numerous novel direct acting antiviral agents that currently are undergoing clinical trials. As our understanding of the HCV virus and its antiviral targets increases, the future of HCV therapy holds the promise of high rates of viral eradication in all patient populations, many or all of whom will be treatable with IFN-free combinations of all-oral agents.

Estimates of HCV-1 patients attaining RVR following dual therapy with peg-interferon and ribavirin

BACKGROUND

Given the significant side-effects and healthcare costs associated with telaprevir- or boceprevir-combination therapy, identifying patients likely to respond to dual therapy peg-interferon (Peg-IFN)/ribavirin is highly desirable. Since the perception of how large the pool of patients who may achieve rapid virologic response (RVR) is vaguely ascertained, we searched the literature for this information.

METHODS

Studies on patients treated with Peg-IFN/ribavirin were identified by searching MEDLINE and analyzed by meta-analysis. The primary end point was weighted estimates of RVR. The influence on race/ethnicity, baseline viremia, type of Peg-IFN, ribavirin dosage, and significant hepatic fibrosis on the results was evaluated.

RESULTS

Across 38 studies on 13,219 patients, the fraction of RVR patients was 19.6 %. The only baseline factor influencing RVR was race/ethnicity, with higher rates in Asian (26.7 %) and Caucasian patients (22.5 %). Of the 1,735 RVR patients, 85.1 % attained sustained virologic response (SVR). In these, SVR was influenced by ribavirin dose (86.8 vs. 72.8 % for high or low), type of Peg-IFN (91.8 % for alpha-2b vs. 82.9 % for alpha-2a), and treatment duration (91.7 % for 48 weeks vs. 79.4 % for 24 weeks).

CONCLUSIONS

One fifth to one fourth of hepatitis C virus genotype 1 (HCV-1) patients can be safely treated with dual therapy of Peg-IFN/ribavirin, and may be spared from cost and inconvenience of regimens considering the addition of HCV protease inhibitors.

Pegylated interferon fractal pharmacokinetics: individualized dosing for hepatitis C virus infection

Despite recent advances in hepatitis C virus (HCV) therapeutics, the combination of pegylated interferon and ribavirin (PEGIFN/RBV) remains the cornerstone of treatment. Optimization and individualization of PEGIFN dosing could improve outcomes. Week one PEGIFN serum concentrations in 42 HCV genotype 1-infected patients treated with conventional PEGIFN/RBV were analyzed using multicompartmental pharmacokinetic models. For each patient, pharmacokinetic parameter estimates, weight, age, interleukin-28B (IL-28B) single-nucleotide polymorphism, CD4 count, baseline HCV RNA, gender, race, and HIV status were examined using classification and regression tree analysis to identify factors predictive of sustained viral response (SVR). Survival analysis was performed to compare the time to undetectable viral load in patients with and without the highest scoring predictor. PEGIFN concentrations varied at least 87-fold. Pharmacokinetics were best described by a two-compartment model with an 8.4-h absorption lag. Patient weight correlated with PEGIFN systemic clearance based on fractal geometry relationships. SVR was achieved in 36% of patients; a PEGIFN cumulative 1-week area under the curve (AUC) of ≤0.79 mg · h/liter scored highest in predicting poor response, followed by a weight of ≥93.7 kg. Patients with a PEGIFN AUC of >0.79 mg · h/liter achieved undetectable viral load more rapidly than those with a lower AUC (hazard ratio, 1.63; 95% confidence interval, 1.21 to 2.04). PEGIFN exhibits wide pharmacokinetic variability, mainly driven by patient weight, so that the standard dose may not reach levels needed to achieve SVR. Optimizing dose to patient weight and PEGIFN AUC in the first week offers a solution to improve SVR and to potentially shorten duration of therapy.

Intensified peginterferon α-2a dosing increases sustained virologic response rates in heavy, high viral load hepatitis C genotype 1 patients with high low-density lipoprotein

BACKGROUND AND GOAL

Patients infected with hepatitis C virus (HCV) with elevated low-density lipoprotein (LDL) levels achieve higher sustained virologic response (SVR) rates after peginterferon (PegIFN)/ribavirin treatment versus patients with lower LDL. Our aim was to determine whether SVR rates in patients with low/elevated LDL can be improved by dose intensification.

STUDY

In PROGRESS, genotype 1 patients with baseline HCV RNA ≥ 400,000 IU/mL and body weight ≥ 85 kg were randomized to 48 weeks of 180 µg/wk PegIFN α-2a (40 kDa) plus ribavirin (A: 1200 mg/d; B: 1400/1600 mg/d) or 12 weeks of 360 µg/wk PegIFN α-2a followed by 36 weeks of 180 µg/wk, plus ribavirin (C: 1200 mg/d; D: 1400/1600 mg/d). This retrospective analysis assessed SVR rates among patients with low (<100 mg/dL) or elevated (≥ 100 mg/dL) LDL. Patients with high LDL (n=256) had higher baseline HCV RNA (5.86 × 10(6) IU/mL) versus patients with low LDL (n=262; 4.02 × 10(6) IU/mL; P=0.0003).

RESULTS

Multiple logistic regression analysis identified a significant interaction between PegIFN α-2a dose and LDL levels on SVR (P=0.0193). The only treatment-related SVR predictor in the nested multiple logistic regression was PegIFN α-2a dose among patients with elevated LDL (P=0.0074); therefore, data from the standard (A+B) and induction (C+D) dose arms were pooled. Among patients with low LDL, SVR rates were 40% and 35% in the standard and induction-dose groups, respectively; SVR rates in patients with high LDL were 44% and 60% (P=0.014), respectively.

CONCLUSIONS

Intensified dosing of PegIFN α-2a increases SVR rates in patients with elevated LDL even with the difficult-to-cure characteristics of genotype 1, high baseline viral load, and high body weight.

Comparison of hepatitis C virus treatment between incarcerated and community patients

The prevalence of chronic hepatitis C virus (HCV) infection among incarcerated individuals in the United States is estimated to be between 12% and 31%. HCV treatment during incarceration is an attractive option because of improved access to health care and directly observed therapy. We compared incarcerated and nonincarcerated HCV-infected patients evaluated for treatment at a single academic center between January 1, 2002 and December 31, 2007. During this period, 521 nonincarcerated and 388 incarcerated patients were evaluated for HCV treatment. Three hundred and nineteen (61.2%) nonincarcerated patients and 234 (60.3%) incarcerated patients underwent treatment with pegylated interferon and ribavirin. Incarcerated patients were more likely to be male, African-American race, and have a history of alcohol or intravenous drug use. Treated incarcerated patients were less likely to have genotype 1 virus and were less likely to have undergone previous treatment. There was a similar prevalence of coinfection with human immunodeficiency virus (HIV) in both groups. A sustained viral response (SVR) was achieved in 97 (42.9%) incarcerated patients, compared to 115 (38.0%) nonincarcerated patients (P = 0.304). Both groups had a similar proportion of patients that completed a full treatment course. Stepwise logistic regression was conducted, and the final model included full treatment course, non-genotype 1 virus, younger age at treatment start, and negative HIV status. Incarceration status was not a significant predictor when added to this model (P = 0.075).

CONCLUSION

In a cohort of HCV-infected patients managed in an academic medical center ambulatory clinic, incarcerated patients were as likely to be treated for HCV and as likely to achieve an SVR as nonincarcerated patients.

The application and mechanism of action of ribavirin in therapy of hepatitis C

Ribavirin has been used as an antiviral agent for several decades. Although it has activity against numerous viruses, its major use clinically has been in the treatment of respiratory syncytial virus in paediatric patients and chronic HCV infection in both children and adults. This review highlights the clinical application and mechanism of action of ribavirin and discusses the future role of ribavirin in treatment of HCV where there are intense research efforts to improve therapy.

Safety profile of standard- vs. high-dose peginterferon alfa-2a plus standard-dose ribavirin in HCV genotype 1/4 patients: pooled analysis from 5 randomized studies

OBJECTIVE

This analysis examines the safety profile of standard- versus high-dose peginterferon alfa-2a.

METHODS

Data were pooled from five trials including HCV genotype 1- or 4-infected naive and treatment-experienced patients (n = 2,940). Patients were randomized to receive peginterferon alfa-2a at 180 μg/week (standard-dose; n = 1,672) or 360 μg/week (high-dose; n = 1,268) plus ribavirin 1,000/1,200 mg/day for 12 weeks; after 12 weeks, all received standard dose. This safety analysis was restricted to the first 12 weeks.

RESULTS

In standard and high-dose groups, similar frequencies of serious adverse events (SAEs, 3.2 and 4.2%, respectively) and treatment discontinuations for safety reasons (2.8 and 2.9%) were reported. More patients reported weight decrease as an adverse event (AE) in the 360 μg/week group (7.7 vs. 3.3%). Significant (p < 0.05) independent predictors for discontinuation due to safety were older age, male gender, lower albumin and low neutrophil count, but not the starting dose of peginterferon alfa-2a. Although more laboratory abnormalities were reported in patients receiving high-dose peginterferon alfa-2a, this was not reflected in AEs or discontinuations, suggesting these are adequately managed by dose modification.

CONCLUSIONS

High-dose peginterferon alfa-2a for 12 weeks does not significantly increase the incidence of SAEs or discontinuations for safety reasons, beyond that of a standard dose regimen.

Impact of obesity on the bioavailability of peginterferon-α2a and ribavirin and treatment outcome for chronic hepatitis C genotype 2 or 3

Background and Aims

Having a body mass index above or equal to 30 kg/m² in conjunction with chronic hepatitis C virus infection is associated with non-responsiveness to treatment with interferon and ribavirin, but details regarding the mechanisms whereby obesity reduces the efficacy of therapy remain unclear.

Methods

This study evaluated impact of obesity on outcome as well as interferon and ribavirin concentrations following standard-of-care fixed dosing with peginterferon-α2a 180 µg once weekly and ribavirin 800 mg daily among 303 HCV genotype 2/3-infected patients enrolled in the per-protocol analysis of a recently completed phase III trial (NORDynamIC).

Results

Patients with BMI ≥30 kg/m² showed poorer outcome following 24 weeks of therapy (SVR 62% vs. 89% for BMI ≥30 vs. <30; P = 0.006) along with significantly higher steatosis grade (P = 0.002), HOMA-IR (P<0.0001), triglyceride levels (P = 0.0002), and baseline viral load (P = 0.028). Obesity was also significantly associated with lower plasma interferon concentrations on days 3, 7, and 29 (P = 0.02, P = 0.0017, and P<0.0001, respectively) and lower plasma ribavirin concentrations day 29 (P = 0.025), and lower concentration of interferon in turn was associated with a poorer first phase reduction in HCV RNA (P<0.0001). In multivariate analysis, ribavirin concentrations week 12, interferon concentrations day 29, and baseline HCV RNA levels were independent predictors of achieving SVR among patients treated for 24 weeks (n = 140).

Conclusions

Reduced bioavailability of interferon and ribavirin along with higher baseline viral load are dominant risk factors for treatment failure in obese patients with chronic hepatitis C.

Reducing Peg-IFN doses causes later virologic response or no response in HCV genotype 1 patients treated with Peg-IFN alfa-2b plus ribavirin

BACKGROUND

The timing to the first undetectable hepatitis C virus (HCV) RNA level is strongly associated with sustained virologic response in pegylated interferon (Peg-IFN) plus ribavirin combination therapy for patients with chronic hepatitis C (CH-C) with genotype 1. This study was conducted to clarify the impact of drug exposure to Peg-IFN on the timing of HCV RNA negativity in Peg-IFN plus ribavirin combination therapy for CH-C patients with genotype 1.

METHODS

A total of 1409 patients treated with Peg-IFN alfa-2b plus ribavirin were enrolled and classified into four categories according to the Peg-IFN dosage. Furthermore, 100 patients were extracted from each Peg-IFN dosage category to adjust for characteristic factors, using the propensity score method.

RESULTS

Peg-IFN exposure was dose-dependently associated with the timing of HCV RNA negativity (p ≤ 0.001). The HCV RNA negative rate at week 4 decreased from 12% with a Peg-IFN dose of >1.5 μg/kg/week to 1-3% with a dose of <1.5 μg/kg/week (p ≤ 0.001), and at week 12 the rate had decreased from 44% with a dose of ≥1.2 μg/kg/week to 18% with a dose of <1.2 μg/kg/week (p = 0.001). Treatment failure (patients without a 1-log decrease of HCV RNA at week 4 or a 2-log decrease of HCV RNA at week 12, or positive at week 24) was found in 54-66% of patients given <1.2 μg/kg/week (p ≤ 0.001), and these patients accounted for 64% of the non-responders.

CONCLUSIONS

The timing of HCV RNA negativity depends significantly on the Peg-IFN dose. Reducing the Peg-IFN dose can induce a later virologic response or non-response in HCV genotype 1 patients treated with Peg-IFN plus ribavirin.

Differences in clinical outcomes among hepatitis C genotype 1-infected patients treated with peginterferon alpha-2a or peginterferon alpha-2b plus ribavirin: a meta-analysis

Background

With the development of new direct acting antiviral (DAA) therapy for hepatitis C, the backbone peginterferon alpha used may be of importance in maximizing treatment outcomes. To this end, the rates of sustained virologic response (SVR), relapse, and treatment discontinuation among hepatitis C genotype 1-infected patients given peginterferon alpha-2a plus ribavirin or peginterferon alpha-2b plus ribavirin were determined using a meta-analysis.

Methods

Randomized trials examining peginterferon alpha-2a or peginterferon alpha-2b co-administered with ribavirin for 48 weeks were included. Data were extracted on SVR, relapse, and treatment discontinuations for treatment-naïve and treatment-experienced patients. Pooled proportions using fixed and random effects meta-analysis were calculated.

Results

Twenty-six trials provided data on patients treated with peginterferon alpha-2a plus ribavirin, and 19 trials provided data on patients treated with peginterferon alpha-2b plus ribavirin. Five trials were direct head-to-head evaluations. In the subset of trials that included head-to-head evaluations, no significant differences were observed between the two treatments for treatment-naïve (relative risk [RR]: 1.07, 95% confidence intervals [CI]: 0.97–1.18) and treatment-experienced patients (RR: 1.27, 95% CI: 0.58–2.77). Using only active trial arms, a larger proportion of the treatment- naïve patients who were provided peginterferon alpha-2a plus ribavirin achieved a SVR (47%), which is greater than that of treatment-naïve patients who were provided peginterferon alpha- 2b plus ribavirin (40% SVR achievement); however, a larger proportion of treatment- experienced patients who were provided peginterferon alpha-2b plus ribavirin achieved a SVR (16%) when compared with treatment-experienced patients given peginterferon alpha-2a plus ribavirin (12% SVR achievement). A larger proportion of relapses occurred among both treatment-naïve and treatment-experienced patients given peginterferon alpha-2a plus ribavirin, when compared with treatment-naïve and treatment-experienced patients taking peginterferon alpha-2b plus ribavirin. The proportion of patients discontinuing treatment was greater among treatment-naïve patients taking peginterferon alpha-2a plus ribavirin, but smaller among treatment-experienced patients.

Conclusion

There are small differences in treatment outcomes for different types of peginterferon- alpha. Patient status and complexity of administration may differentiate clinical outcomes.

HCV and the hepatic lipid pathway as a potential treatment target

Atherosclerosis has been described as a liver disease of the heart [1]. The liver is the central regulatory organ of lipid pathways but since dyslipidaemias are major contributors to cardiovascular disease and type 2 diabetes rather than liver disease, research in this area has not been a major focus for hepatologists. Virus-host interaction is a continuous co-evolutionary process [2] involving the host immune system and viral escape mechanisms [3]. One of the strategies HCV has adopted to escape immune clearance and establish persistent infection is to make use of hepatic lipid pathways. This review aims to: • update the hepatologist on lipid metabolism • review the evidence that HCV exploits hepatic lipid pathways to its advantage • discuss approaches to targeting host lipid pathways as adjunctive therapy.

Rationale, challenges, and participants in a Phase II trial of a botanical product for chronic hepatitis C

BACKGROUND

Chronic hepatitis C is associated with significant morbidity and mortality as a consequence of progression to cirrhosis, hepatocellular carcinoma, and liver failure. Current treatment for chronic hepatitis C with pegylated interferon (IFN) and ribavirin is associated with suboptimal responses and numerous adverse effects. A number of botanical products have been used to treat hepatic disorders. Silymarin, extracted from the milk thistle plant, Silybum marianum (L) Gaertn. (Asteraceae), has been most widely used for various liver disorders, including chronic hepatitis C, B, and alcoholic liver disease. However, the safety and efficacy of silymarin have not been studied systematically in chronic hepatitis C.

PURPOSE

We describe our strategy for a phased approach for studying the impact of silymarin in hepatitis C, in the context of the unique challenges of botanical product clinical trials and the development of specific and curative antiviral therapy.

METHODS

This multicenter, randomized, double-masked, placebo-controlled trial was conducted with four clinical centers and a data-coordinating center in the United States, to assess the impact of silymarin therapy in patients with chronic hepatitis C who failed conventional antiviral therapy.

RESULTS

Key aspects relevant to performing clinical trials of botanical products include early identification of an appropriate product with standard product chemistry, acquisition of pharmacokinetic and dosing information, selection of the appropriate study group, and choosing rigorous outcome variables. POTENTIAL LIMITATIONS: Trial participants were chronic hepatitis C patients who were nonsustained virologic responders to IFN-based therapy; therefore, the findings are not generalizable to all hepatitis C populations. Further, alanine aminotransferase, a biochemical liver test, rather than hepatitis viral RNA or liver histology was the primary end point.

CONCLUSIONS

The challenges identified and addressed during development of this United States multicenter Phase II trial to evaluate silymarin for treatment of patients with chronic hepatitis C infection who had failed to respond successfully to previous IFN-based therapy are common and must be addressed to conduct rigorous trials of botanical products.

Effect of an induction period of pegylated interferon-α2a and ribavirin on early virological response in HIV-HCV-coinfected patients: results from the CORAL-2 study

BACKGROUND

It is uncertain whether a 4-week induction period of pegylated interferon and ribavirin increases early virological response (EVR) in HIV-HCV-coinfected patients.

METHODS

HIV and HCV genotype 1- and 4-coinfected subjects were randomized to receive pegylated interferon-α2a 270 μg/week plus ribavirin 1,600 mg daily and epoetin-β for 4 weeks, followed by pegylated interferon-α2a at standard dosages plus weight-based ribavirin (WBR) dosage for 8 weeks (induction arm [IA]), or pegylated interferon-α2a plus WBR for 12 weeks (standard therapy arm [SA]). HCV RNA was determined at weeks 0, 1, 2, 3, 4, 8 and 12. Ribavirin plasma trough concentrations were determined at weeks 4 (RBV-C(4)) and 12 (RBV-C(12)).

RESULTS

A total of 67 patients were included; 33 in the SA and 34 in the IA. Overall, 25% received nucleoside reverse transcriptase inhibitor (NRTI)-sparing regimens. More patients achieved an HCV RNA decrease ≥1 log(10) at week 4 in the IA than in the SA (62% versus 38%; P=0.017), but EVR rates were similar in the two groups (74% versus 59% in the IA and SA, respectively; P=0.15). Independent predictors of faster HCV RNA decrease at 12 weeks were higher RBV-C(4) and younger age. RBV-C(4) were higher in patients allocated in the IA and in those receiving NRTIs (P=0.039).

CONCLUSIONS

A 4-week induction with pegylated interferon-α2a plus ribavirin was associated with a greater decrease in HCV RNA at week 4; however, this did not translate into higher EVR rates. Higher RBV doses and avoidance of NRTI-sparing antiretroviral regimens might improve HCV treatment efficacy.

Interferon-free regimens: the near future, the likely and the not so likely

Remarkable progress has been achieved in the treatment of chronic hepatitis C virus (HCV) since interferon was first used to treat this pathogen more than 20 years ago. This article reviews the mechanisms through which interferon is believed to suppress HCV and lead to SVR. These observations are used to speculate as to whether an all-oral antiviral cocktail could "cure" HCV in the near future.