First phase hepatitis c viral kinetics in previous nonresponders patients

Improved pharmacodynamics and pharmacokinetics after i.v. application of peginterferon alfa-2a in hepatitis C null responders

BACKGROUND & AIM

Mechanisms of non-responsiveness to peginterferon alfa-2a are not completely understood. Inadequate plasma levels may contribute to reduced response. The aim of this prospective, multicentre, crossover, Phase 1 study was to evaluate the pharmacokinetics and viral kinetics of intravenous vs. subcutaneous peginterferon alfa-2a in patients with genotype 1 chronic hepatitis C infection who showed null response to previous peginterferon/ribavirin.

METHODS

Patients were randomized in four treatment arms to subcutaneous or intravenous peginterferon alfa-2a 180 μg, once or twice weekly for 2 weeks. After a washout phase of 6 weeks, patients first receiving intravenous administration switched to subcutaneous or vice versa for additional 2 weeks.

RESULTS

Intravenous administration of pegylated interferon resulted in a stronger and faster decline in HCV RNA than subcutaneous administration with a maximum decline of 1.17 log10 vs. 0.41 log10 or 1.32 log10 vs. 0.54 log10 after a once or twice weekly application, respectively. Pharmacokinetic studies revealed significantly higher maximum concentration (C(max))(0-12) h and C(max 0-7) d following intravenous administration, irrespective of dosing frequency A rapid rebound in HCV RNA was observed in all treatment arms. Adverse events occurred more frequently following intravenous administration.

CONCLUSION

Intravenous administration of peginterferon alfa-2a results in considerably higher plasma concentration and a stronger decline in HCV RNA and offers an interesting approach in order to overcome interferon non-responsive state in patients with full null response to previous peginterferon/ribavirin combination therapy.

Differential antiviral effects of pegylated interferon-α2a and pegylated interferon-α2b in chronic hepatitis C

BACKGROUND AND OBJECTIVES

Pegylated interferon (peg-IFN)-α2a and -α2b show different pharmacokinetic properties but are used interchangeably for hepatitis C treatment in traditional dual combinations and with newer agents. We assessed whether peg-IFN antiviral effects vary with peg-IFN subtype, affecting viral response in a differential manner.

METHODS

Chronic hepatitis C patients treated with ribavirin combined with peg-IFN-α2a (N = 109) or -α2b (N = 114) were studied. Hepatitis C virus RNA quantitation was performed by Cobas TaqMan 5 min before treatment start and subsequently after 48/72 h and 7, 14, 28 and 90 days. Antiviral effect was assessed in terms of viraemia changes over treatment. Histology grading and staging, interleukin-28B (IL28B) status and baseline viral genotype, alanine aminotransferase, gamma glutamyltransferase and glucose were analysed.

RESULTS

Viraemia decline after 48/72 h and 7 days was significantly greater with peg-IFN-α2b (1.96 and 2.12 vs 1.49 and 1.20 log10 IU/mL with peg-IFN-α2a; p < 0.001). Differences were of larger extent in patients with advanced fibrosis (p = 0.002), genotype 1 infection (p = 0.002) and CT/TT genotypes of IL28B (p = 0.001). A rebound in viral load was observed significantly more often after the first dose in patients treated with peg-IFN-α2b (78 vs 28 % in those with peg-IFN-α2a; p = 0.0001). Differences between peg-IFNs disappeared by day 28 of treatment.

CONCLUSION

There are significant pharmacodynamic differences between peg-IFN-α2a and -α2b in the early phase of chronic hepatitis C treatment. The greater early viral decline observed with peg-IFN-α2b was essentially confined to 'difficult to treat' patients. Whether this could affect response-guided treatment decision making, as well as triple drug regimens, needs to be assessed.

IL28B polymorphisms predict reduction of HCV RNA from the first day of therapy in chronic hepatitis C

BACKGROUND & AIMS

Single nucleotide polymorphisms (SNPs) associated with IL28B influence the outcome of peginterferon-α/ribavirin therapy of chronic hepatitis C virus (HCV) infection. We analyzed the kinetics of HCV RNA during therapy as a function of IL28B SNPs.

METHODS

IL28B SNPs rs8099917, rs12979860, and rs12980275 were genotyped in 242 HCV treatment-naïve Caucasian patients (67% genotype 1, 28% genotype 2 or 3) receiving peginterferon-α2a (180 μg weekly) and ribavirin (1000-1200 mg daily) with serial HCV-RNA quantifications. Associations between IL28B polymorphisms and early viral kinetics were assessed, accounting for relevant covariates.

RESULTS

In the multivariate analyses for genotype 1 patients, the T allele of rs12979860 (T(rs12979860)) was an independent risk factor for a less pronounced first phase HCV RNA decline (log(10) 0.89IU/ml among T carriers vs. 2.06 among others, adjusted p < 0.001) and lower rapid (15% vs. 38%, adjusted p = 0.007) and sustained viral response rates (48% vs. 66%, adjusted p < 0.001). In univariate analyses, T(rs12979860) was also associated with a reduced second phase decline (p = 0.002), but this association was no longer significant after adjustment for the first phase decline (adjusted p = 0.8). In genotype 2/3 patients, T(rs12979860) was associated with a reduced first phase decline (adjusted p = 0.04), but not with a second phase decline.

CONCLUSIONS

Polymorphisms in IL28B are strongly associated with the first phase viral decline during peginterferon-α/ribavirin therapy of chronic HCV infection, irrespective of HCV genotype.

Review of consensus interferon in the treatment of chronic hepatitis C

Consensus interferon (CIFN) is an artificially engineered interferon that reflects most of the human genotype 1 interferons and shows a higher biological and antiviral capacity in vitro. It has been used internationally to treat patients with chronic hepatitis C (HCV) infection before pegylated IFN became available. To mimic the half-life of PEG-IFN it has to be administered on a daily basis. The gold standard in the treatment of hepatitis C is well established and recommended. Today patients are being treated with a combination therapy of pegylated IFN and ribavirin. Length and dosage of therapy depends on the genotype of the virus. Patients with genotype 1 and 4 and high viral load should be treated for 48 weeks; for patients with these genotypes along with either low viral load or early virological response, therapy for 24 weeks is sufficient. Patients with genotype 2 and 3 should be treated for up to 24 weeks. However, daily dosing of IFN-α, eg, CIFN, resulting in a higher cumulative dosage, might be beneficial and more efficacious in some chronic HCV-infected patients. Patients with genotype 1, having initially high viral load (>800,000 IU/mL) and showing advanced liver disease with progressive fibrosis or even cirrhosis comprise the difficult-to-treat in order to overcome the infection. This review summarizes and critically discusses the published data on the treatment of HCV with CIFN.

Hepatitis C Viral Kinetics in the Era of Direct Acting Antiviral Agents and IL28B

In the last decade hepatitis C virus (HCV) kinetics has become an important clinical tool for the optimization of therapy with (pegylated)-interferon-α (IFN) and ribavirin (RBV). Mathematical models have generated important insights into HCV pathogenesis, HCV- host dynamics, and IFN and RBV's modes of action. Clinical trials with direct acting agents (DAAs) against various steps of the HCV life cycle have revealed new viral kinetic patterns that have not been observed with IFN±RBV. Very recently, studies have showed that single nucleotide polymorphisms (SNPs) in the IL28B gene region were associated with race/ethnicity and with response to IFN±RBV. Here we review our current knowledge of HCV kinetics and related mathematical models during IFN±RBV and/or DAA based therapies, HCV pathogenesis, and the role of IL28B polymorphism on early HCV kinetics. Better understanding of the mode of actions of drug(s) and viral kinetics may help to develop, in the near future, new individualized therapeutic regimens that include DAAs in combination with IFN+RBV.

Very early prediction of response to HCV treatment with PEG-IFN-alfa-2a and ribavirin in HIV/HCV-coinfected patients

The objective of this study was to find very early viral kinetic markers to predict nonresponse to hepatitis C virus (HCV) therapy in a group of human immunodeficiency virus (HIV)/HCV-coinfected patients. Twenty-six patients (15 HCV genotype-1 and 11 genotype-3) were treated with a 48-week regimen of peginterferon-alfa-2a (PEG-IFN) (180 μg/week) and weight-based ribavirin (11 mg/kg/day). Samples were collected at baseline; 4, 8, 12, 18, 24, 30, 36 and 42 h; days 2, 3, 4, 7, 8, 15, 22, 29, 43 and 57 then weekly and monthly. Five patients discontinued treatment. Seven patients (27%) achieved a sustained virological response (SVR). Nadir HCV RNA levels were observed 1.6 ± 0.3 days after initiation of therapy, followed by a 0.3- to 12.9-fold viral rebound until the administration of the second dose of PEG-IFN, which were not associated with SVR or HCV genotype. A viral decline <1.19 log for genotype-1 and <0.97 log for genotype-3, 2 days after starting therapy, had a negative predictive value (NPV) of 100% for SVR. The day 2 virological response had a similar positive predictive value for SVR as a rapid virological response at week 4. In addition, a second-phase viral decline slope (i.e., measured from day 2 to 29) <0.3 log/week had a NPV = 100% for SVR. We conclude that first-phase viral decline at day 2 and second-phase viral decline slope (<0.3 log/week) are excellent predictors of nonresponse. Further studies are needed to validate these viral kinetic parameters as early on-treatment prognosticators of nonresponse in patients with HCV and HIV.

IP-10 predicts the first phase decline of HCV RNA and overall viral response to therapy in patients co-infected with chronic hepatitis C virus infection and HIV

The aim of this study was to investigate the utility of baseline plasma interferon-gamma inducible protein-10 (IP-10) levels in human immunodeficiency virus (HIV)-hepatitis C virus (HCV) co-infected patients. Baseline IP-10 was monitored during HCV combination therapy in 21 HIV-HCV co-infected patients (HCV genotype 1 (n = 16), 2 (n = 2), and 3 (n = 3)). Lower baseline IP-10 was significantly associated with a rapid decline in HCV RNA, in particular with the first phase reduction, and similar cut-off levels (< 150 and > 600 pg/ml) as in HCV mono-infected patients apply. In conclusion, baseline IP-10 < 150 pg/ml is predictive of a favourable viral response to HCV therapy in HIV-HCV co-infected patients, and may thus be useful in encouraging such difficult-to-treat patients to initiate therapy.

Systemic and intrahepatic interferon-gamma-inducible protein 10 kDa predicts the first-phase decline in hepatitis C virus RNA and overall viral response to therapy in chronic hepatitis C

High systemic levels of interferon-gamma-inducible protein 10 kDa (IP-10) at onset of combination therapy for chronic hepatitis C virus (HCV) infection predict poor outcome, but details regarding the impact of IP-10 on the reduction of HCV RNA during therapy remain unclear. In the present study, we correlated pretreatment levels of IP-10 in liver biopsies (n = 73) and plasma (n = 265) with HCV RNA throughout therapy within a phase III treatment trial (DITTO-HCV). Low levels of plasma or intrahepatic IP-10 were strongly associated with a pronounced reduction of HCV RNA during the first 24 hours of treatment in all patients (P < 0.0001 and P = 0.002, respectively) as well as when patients were grouped as genotype 1 or 4 (P = 0.0008 and P = 0.01) and 2 or 3 (P = 0.002, and P = 0.02). Low plasma levels of IP-10 also were predictive of the absolute reduction of HCV RNA (P < 0.0001) and the maximum reduction of HCV RNA in the first 4 days of treatment (P < 0.0001) as well as sustained virological response (genotype 1/4; P < 0.0001). To corroborate the relationship between early viral decline and IP-10, pretreatment plasma samples from an independent phase IV trial for HCV genotypes 2/3 (NORDynamIC trial; n = 382) were analyzed. The results confirmed an association between IP-10 and the immediate reduction of HCV RNA in response to therapy (P = 0.006). In contrast, pretreatment levels of IP-10 in liver or in plasma did not affect the decline of HCV RNA between days 8 and 29, i.e., the second-phase decline, or later time points in any of these cohorts.

CONCLUSION

In patients with chronic hepatitis C, low levels of intrahepatic and systemic IP-10 predict a favorable first-phase decline of HCV RNA during therapy with pegylated interferon and ribavirin for genotypes of HCV.

Hepatitis C Viral Kinetics in Special Populations

Mathematical models of hepatitis C viral (HCV) kinetics provide a means of estimating the antiviral effectiveness of therapy, the rate of virion clearance and the rate of loss of HCV-infected cells. They have also proved useful in evaluating the extrahepatic contribution to HCV plasma viremia and they have suggested mechanisms of action for both interferon-α and ribavirin. Viral kinetic models can explain the observed HCV RNA profiles under treatment, e.g., flat partial response, biphasic and triphasic viral decay and viral rebound. Current therapy with (pegylated) interferon-α and ribavirin has a poorer success in patients having insulin resistance, hepatic fibrosis, African American ethnicity, HCV/HIV-coinfection, HCV genotype-1 and high baseline viral load. The use of mathematical modeling and statistical analysis of experimental data have been useful in understanding some of these treatment obstacles.

Early and sustained virological response in non-responders with chronic hepatitis C: a randomized open-label study of pegylated interferon-alpha-2a versus pegylated interferon-alpha-2b

OBJECTIVES

The purpose of this randomized open-label study was to assess the efficacy of treatment with pegylated interferon-alpha-2a versus pegylated interferon-alpha-2b, both plus ribavirin, in inducing early and sustained virological response (EVR and SVR) in chronic hepatitis C non-responders.

PATIENTS AND METHODS

A total of 108 patients with chronic hepatitis C who were non-responders to previous combined therapy (standard interferon-alpha plus ribavirin for > or = 3 months) were enrolled and equally randomized into two groups in this intention-to-treat analysis. The patients exhibited similar baseline features. One group received subcutaneous pegylated interferon-alpha-2a 180 microg once weekly, while the other was treated with subcutaneous pegylated interferon-alpha-2b 1.5 microg/kg once weekly. Ribavirin 15 mg/kg/day was included in both protocols. Treatment duration for EVR was 12 weeks. Patients who demonstrated non-detectable hepatitis C virus (HCV) RNA or a > or = 2 log(10) reduction in viral load at week 12 continued therapy up to 48 weeks, with assessments every 3 months during a follow-up of 24 weeks.

RESULTS

All patients in both groups completed the EVR study, then seven patients receiving pegylated interferon-alpha-2a and seven patients receiving pegylated interferon-alpha2b discontinued treatment as a result of severe adverse effects. After 12 weeks of treatment, viral load reduction was >2 log(10) with both pegylated interferon-alpha-2a (-2.53) and pegylated interferon-alpha-2b (-2.48) with no significant difference. At the end of week 48, HCV RNA was undetectable in 14 of 54 patients (25.9%) receiving pegylated interferon-alpha-2a and in 15 of 54 patients (27.7%) receiving pegylated interferon-alpha-2b. When terminating follow-up, an SVR was observed in 11 of 54 patients (20.4%) who received pegylated interferon-alpha-2a and 10 of 54 patients (18.4%) receiving pegylated interferon-alpha-2b. The incidence and severity of adverse events was similar in both groups.

CONCLUSIONS

Our results seem to show that in chronic hepatitis C patients who are non-responsive to previous therapy, EVR to the two pegylated interferons did not significantly differ with a similar therapeutic efficacy defined as SVR.

Very Early Viral Kinetics on Interferon Treatment in Chronic Hepatitis C virus Genotype 4 Infection

Background

Interferon (IFN)-resistant hepatitis C virus strains limit efficacy of antiviral combination therapy in patients infected with genotypes 1 and 4. A single test dose of IFN was useful to identify non-responders to IFN-α2b/ribavirin (RBV) or likely non-responders to pegylated (PEG)-IFN-α2a/RBV therapy in genotype 1 patients. Our aim was to investigate this approach in genotype 4 patients.

Methods

Viral load was measured in 46 patients before and 24 h after 10 megaunits (MU) IFN-α2b, and before and during 2 weeks of daily 5 MU IFN-α2b administration. Thereafter, patients received 48 weeks combination therapy with either 180 μg PEG-IFN-α2a/week ( n=33), 1.5 μg/kg PEG-IFN-α2b/week ( n=7) or 5 MU IFN-α2b/2 days ( n=6), along with 1–1.2g RBV/day. For prediction analysis the largest group (PEG-IFN-α2a) was evaluated only.

Results

Median 24 h log10 change after 10 MU IFN-α2b was 1.15 (range 0.08–2.48) and after 5 MU IFN-α2b was 0.81 (-0.12–2.22; P<0.0001). Log10 changes after 2 weeks on 5 MU IFN-α2b daily and 24 h after 10 MU were the best predictors of early virological response (defined by negativity of a standard qualitative PCR) to PEG-IFN-α2a/RBV combination therapy (area under curve [AUC]=0.97; P<0.001, receiver operating characteristics), 24 h log10 change after 10 MU was the best predictor of sustained virological response (SVR; AUC=0.91, P=0.001).

Conclusion

As in genotype 1 patients, there is large variation in IFN responsiveness, including the presence of resistant strains, in genotype 4 patients. A 24 h log10 change after 10 MU IFN-α2b is an excellent predictor of SVR on PEG-IFNα2a/RBV combination therapy. This test may be useful to obtain homogeneous groups for clinical studies and could help in clinical decision making.

Nonresponse to treatment for hepatitis C: current management strategies

Chronic hepatitis C affects >170 million people worldwide, causing cirrhosis and liver cancer in a sizeable proportion of patients. Substantial progress has been made in the treatment of chronic hepatitis C. More than 50% of patients can achieve sustained virological response after 24-48 weeks of interferon and ribavirin combination therapy, making chronic hepatitis C a potentially curable disease. However, a large proportion of patients with chronic hepatitis C do not clear the virus after current standard therapy. Hepatitis C virus develops two pathways to counteract the antiviral effect of interferon. Some chronic hepatitis C patients may have a virus that is more resistant to interferon therapy, while other patients appear to have defective immune responses or poor tolerance or compliance to interferon-based antiviral therapy. The possible strategies to improve antiviral efficiency in these nonresponders are to increase the dosage, prolong the duration of treatment and improve the compliance of patients. A total of 6-15% of prior nonresponders to standard interferon plus ribavirin therapy will respond to re-treatment with peginterferon plus ribavirin, while 32-50% of patients who have relapsed will respond to re-treatment. New small molecules are under development to treat chronic hepatitis C and may be important particularly in the treatment of prior nonresponders to current standard therapy.

Optimizing treatment regimens in hepatitis C

Scientists and clinicians have made tremendous advances in understanding the pathogenesis of hepatitis C virus (HCV) infection and have developed impressive strategies for treating this hepatotropic virus in the short time since its discovery in 1989. This article goes beyond the current guidelines for the treatment of HCV infection to examine the use of multiple pretreatment factors to predict response; the use of viral kinetics to guide length of treatment; higher dose ribavirin in genotype 1 infection; retreatment of non responders and relapsers; and improving adherence to therapy.

Pegylated interferon alfa-2b plus ribavirin in the retreatment of interferon-ribavirin nonresponder patients

BACKGROUND & AIMS

Inadequate data are available about retreatment of nonresponders to interferon (IFN) and ribavirin. Thus, this study evaluated the efficacy and tolerability of a 48-week therapy with pegylated IFN-alpha-2b plus high-dose ribavirin in patients who have failed to respond to the combination. Treatment up to 48 weeks also in patients who have failed to clear hepatitis C virus (HCV) RNA by week 24 was also evaluated.

METHODS

One hundred forty-one patients who previously did not respond to IFN and ribavirin, 86% with genotype 1 or 4 infection, 52% with high viral load (>800.000 IU/mL), 22% with cirrhosis, were retreated with pegylated IFN-alpha-2b 1.5 microg/kg per week and ribavirin 1000-1200 mg/day for 48 weeks and followed up for 24 weeks.

RESULTS

By intent-to-treat analysis, 20% of patients achieved a sustained virologic response (SVR). SVR of genotype 1 patients was 19%. Independent predictors of SVR were low gamma-glutamyltransferase levels (OR, 22.9; 95% CI: 6.6-79.6) and low viral load (OR, 3.8; 95% CI: 1.1-12.6). Twelve (23%) out of 51 patients who were HCV RNA positive after 24 weeks of therapy achieved a late virologic response (after week 24) and 5 (10%) of them, all with genotype 1, achieved an SVR. Genotype was not associated with response (P = .2) or with early response (P = .3).

CONCLUSIONS

Retreatment with pegylated IFN-alpha-2b and ribavirin of multi-experienced and "difficult to treat" nonresponder patients produced a very promising SVR. Accurate selection of patients, such as those with low viral load and low gamma-glutamyltransferase levels, and prolongation of therapy beyond 24 weeks also in HCV RNA-positive patients may further increase the rate of SVR.

The kinetics of hepatitis C virus

The kinetics of hepatitis C virus (HCV) RNA during the first weeks of interferon-based antiviral therapy can be analysed by specific mathematical models. Those models have been inspired by previous work on the kinetics of human immune deficiency virus (HIV) and hepatitis B virus (HBV) during antiviral therapy and are able to summarize important features of early response to antiviral therapy in patients chronically infected with HCV. Kinetic parameters of the underlying biological processes as viral clearance and infected cell loss as well as an efficiency factor of therapy on viral production can be obtained when fitting frequent quantifications of HCV RNA with such models. The main aims of analysing hepatitis C viral kinetics include the efficient comparison of different treatment regimens, prediction of virological response, and conclusions on antiviral mechanisms of therapy.

Treatment with daily consensus interferon (CIFN) plus ribavirin in non-responder patients with chronic hepatitis C: a randomized open-label pilot study

BACKGROUND/AIMS

Therapeutic options for hepatitis C non-responder patients are limited.

METHODS

We initiated an open-label pilot study to investigate the efficacy of CIFN plus ribavirin on viral kinetics, sustained virological response (SVR), and histological response in hepatitis C non-responder patients. Seventy-seven patients were enrolled to receive CIFN given daily in combination with 1000/1200 mg ribavirin. An 8-week induction-dosing regimen of 18 microg CIFN, followed by 9 microg for 40 weeks was compared to 9 microg CIFN for 48 weeks. 90% of patients were infected with HCV-genotype 1.

RESULTS

Overall, 82% of the patients demonstrated an early virological response, 65% had an end-of-treatment response, and the SVR was 30%. Interferon/ribavirin non-responders demonstrated a SVR of 22%. Induction-dosing resulted in a greater first-phase HCV-RNA decay that, however, did not translate to better SVRs, presumably due to more dose modifications. High ALT, younger age, and second-phase viral kinetics were associated with SVR. Only sustained responders and relapse patients showed an improved liver histology.

CONCLUSIONS

Daily dosing of CIFN plus ribavirin may be a promising concept for selected non-responder patients before considering therapies which are anti-viral but not curative. However, motivation and compliance are requisites and a CIFN induction is not required.

Benefit of hepatitis C virus core antigen assay in prediction of therapeutic response to interferon and ribavirin combination therapy

A highly sensitive second-generation hepatitis C virus (HCV) core antigen assay has recently been developed. We compared viral disappearance and first-phase kinetics between commercially available core antigen (Ag) assays, Lumipulse Ortho HCV Ag (Lumipulse-Ag), and a quantitative HCV RNA PCR assay, Cobas Amplicor HCV Monitor test, version 2 (Amplicor M), to estimate the predictive benefit of a sustained viral response (SVR) and non-SVR in 44 genotype 1b patients treated with interferon (IFN) and ribavirin. HCV core Ag negativity could predict SVR on day 1 (sensitivity = 100%, specificity = 85.0%, accuracy = 86.4%), whereas RNA negativity could predict SVR on day 7 (sensitivity = 100%, specificity = 87.2%, accuracy = 88.6%). None of the patients who had detectable serum core Ag or RNA on day 14 achieved SVR (specificity = 100%). The predictive accuracy on day 14 was higher by RNA negativity (93.2%) than that by core Ag negativity (75.0%). The combined predictive criterion of both viral load decline during the first 24 h and basal viral load was also predictive for SVR; the sensitivities of Lumipulse-Ag and Amplicor-M were 45.5 and 47.6%, respectively, and the specificity was 100%. Amplicor-M had better predictive accuracy than Lumipulse-Ag in 2-week disappearance tests because it had better sensitivity. On the other hand, estimates of kinetic parameters were similar regardless of the detection method. Although the correlations between Lumipulse-Ag and Amplicor-M were good both before and 24 h after IFN administration, HCV core Ag seemed to be relatively lower 24 h after IFN administration than before administration. Lumipulse-Ag seems to be useful for detecting the HCV concentration during IFN therapy; however, we still need to understand the characteristics of the assay.