A multicenter, randomized trial of daily high-dose interferon-alfa 2b for the treatment of chronic hepatitis c: pretreatment stratification by viral burden and genotype

Differentially expressed microRNAs in Huh-7 cells expressing HCV core genotypes 3a or 1b: potential functions and downstream pathways

microRNA (miRNA) dysfunction is believed to play important roles in human diseases, including viral infectious diseases. Hepatitis C virus (HCV) infection promotes the development of steatosis, cirrhosis and hepatocellular carcinoma, which is genotype-specific. In order to characterize the miRNA expression profile of Huh-7 cells expressing the HCV core 3a vs. 1b, microarrays and real-time PCR were performed. Consequently, 16 miRNAs (5 miRNAs upregulated and 11 miRNAs downregulated) were found to be dysregulated. In addition, we generated the predicted and validated targets of the differentially expressed miRNAs and explored potential downstream function categories and pathways of target genes using databases of Gene Ontology (GO) and PANTHER and the database for annotation, visualization and integrated discovery (David). The computational results indicated that the dysregulated miRNAs might perform the functions of cellular metabolism and cellular growth. Finally, these biological effects were preliminarily validated. This study identifies a specific miRNA expression profile in cells expressing HCV core proteins of different genotypes (genotype 3a and 1b), which may account for the variable pathophysiological manifestation associated with HCV infection.

Deciphering the interleukin 28B variants that better predict response to pegylated interferon-α and ribavirin therapy in HCV/HIV-1 coinfected patients

Previous works have documented the contribution of different IL28B-associated SNPs to spontaneous HCV clearance. This study investigated the effect of different interleukin (IL) 28B genetic variants on interferon (IFN)-based therapy response. We genotyped eight IL28B single-nucleotide polymorphisms (SNPs) in a cohort of 197 hepatitis C virus (HCV)/human immunodeficiency virus type 1 (HIV-1) coinfected patients from our clinic unit who received combined pegylated (peg)-IFN-α and ribavirin (RBV) therapy. This analysis included the two strongest tag predictors for HCV clearance, rs8099917 and rs12979860, and four causal variants (rs4803219, rs28416813, rs8103142, and rs4803217) located in the IL28B promoter, coding, and 3'-untranslated regions. Haplotypes carrying the major alleles at IL28B SNPs were highly associated with sustained virological responses (SVRs) after treatment with peg-IFN-α and RBV [odds ratio (OR) = 2.5, 95% confidence interval (CI) = 1.6-4.0, 4.0×10(-5)]. Three causal SNP genotypes (rs28416813, rs8103142, and rs4803217) displayed the highest association with SVRs (OR = 3.7, 95% CI = 2.0-6.7, p = 1.3×10(-5)). All four causal variants were in high linkage disequilibrium, both among themselves (r(2)≥0.94) and with the rs12979860 variant (r(2)≥0.92). In contrast, rs8099917 was in low linkage disequilibrium with the four causal variants (r(2)≤0.45) and with the rs12979860 variant (r(2) = 0.45). These results demonstrate that rs12979860, compared to rs8099917, may be a better predictor of response to the peg-IFN/RBV treatment among HCV/HIV-1 coinfected patients. Moreover, causal IL28B variants are strongly associated with treatment SVRs.

Impact of viral amino acid substitutions and host interleukin-28b polymorphism on replication and susceptibility to interferon of hepatitis C virus

Amino acid (aa) substitutions of core 70 and 91 and in the NS5A (nonstructural protein 5A) interferon sensitivity determining region (ISDR) as well as genetic polymorphisms in the host interleukin-28B (IL28B) locus affect the outcome of interferon (IFN)-based therapies for patients with chronic hepatitis C. The combination of these factors and the quasispecies nature of the virus complicate understanding of the underlying mechanism. Using infectious hepatitis C virus (HCV) genotype 1b clone HCV-KT9, we introduced substitutions at both core aa70 (Arg to Gln) and aa91 (Leu to Met). We also introduced four and nine ISDR aa substitutions into core mutant HCV-KT9. Using human hepatocyte chimeric mice with different IL28B genotypes, we examined the infectivity, replication ability, and susceptibility to IFN of these clones. Although aa substitutions in the ISDR significantly impaired infectivity and replication ability of the virus, core aa70 and 91 substitutions did not. The effect of IFN treatment was similar in core wild-type and mutant viruses. Interestingly, virus titer was significantly higher in mice with the favorable IL28B allele (rs8099917 TT and rs12979860 CC) in the transplanted hepatocytes than in mice with hepatocytes from rs8099917 TG and rs12979860 TT donors (P < 0.001). However, the effect of IFN was significantly greater, and intrahepatic expression levels of IFN-stimulated genes were significantly higher in mice with the favorable IL28B allele.

CONCLUSION

Our data suggest that HCV replication levels and response to IFN are affected by human hepatocyte IL28B single-nucleotide polymorphism genotype and mutations in the ISDR. The mechanism underlying the clinically observed association of wild-type core protein in eradication-favorable host cells should be investigated further.

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.

Molecular and epidemiological profiles of hepatitis C virus genotype 4 in Denmark

The prevalence of hepatitis C virus (HCV) genotype 4 has increased throughout Europe. This is an epidemiological study of patients infected chronically with HCV genotype 4 in Denmark. The HCV strains analyzed originated from patient samples collected between 1999 and 2007 as part of the national Danish hepatitis B and C network, DANHEP. Sequence analyses were based on the envelope 1 region of HCV. Results from a total of 72 patients indicated a high degree of genetic heterogeneity. Fifty-six patients (78%) were infected with one of the three dominating subtypes: 4d, 4a, or 4r. The remaining 16 patients (22%) were infected with subtypes 4h, 4k, 4l, 4n, 4o, or 4Unclassified. Three epidemiological profiles were identified: (1) patients infected with HCV by intravenous drug use were infected solely with subtype 4d. They were all of European origin, and 15 of the 16 patients were ethnic Danes. No single transmission event could be confirmed, but the pairwise nucleotide identity within the patients of Danish origin was relatively high (∼95%), suggesting a recent introduction into Denmark. (2) The 21 patients infected with subtype 4a all came from Northern Africa, Egypt, Pakistan, or the Middle East. (3) Patients from Southern Africa dominated among patients infected with subtype 4r (10 of 12 patients). This study demonstrates that HCV genotype 4d has been introduced in and spread among Danish intravenous drug users. The remaining subtypes show restricted distribution, infecting almost exclusively patients from geographical areas with a relatively high prevalence of HCV genotype 4 infections.

Differential in vitro effects of intravenous versus oral formulations of silibinin on the HCV life cycle and inflammation

Silymarin prevents liver disease in many experimental rodent models, and is the most popular botanical medicine consumed by patients with hepatitis C. Silibinin is a major component of silymarin, consisting of the flavonolignans silybin A and silybin B, which are insoluble in aqueous solution. A chemically modified and soluble version of silibinin, SIL, has been shown to potently reduce hepatitis C virus (HCV) RNA levels in vivo when administered intravenously. Silymarin and silibinin inhibit HCV infection in cell culture by targeting multiple steps in the virus lifecycle. We tested the hepatoprotective profiles of SIL and silibinin in assays that measure antiviral and anti-inflammatory functions. Both mixtures inhibited fusion of HCV pseudoparticles (HCVpp) with fluorescent liposomes in a dose-dependent fashion. SIL inhibited 5 clinical genotype 1b isolates of NS5B RNA dependent RNA polymerase (RdRp) activity better than silibinin, with IC50 values of 40-85 µM. The enhanced activity of SIL may have been in part due to inhibition of NS5B binding to RNA templates. However, inhibition of the RdRps by both mixtures plateaued at 43-73%, suggesting that the products are poor overall inhibitors of RdRp. Silibinin did not inhibit HCV replication in subgenomic genotype 1b or 2a replicon cell lines, but it did inhibit JFH-1 infection. In contrast, SIL inhibited 1b but not 2a subgenomic replicons and also inhibited JFH-1 infection. Both mixtures inhibited production of progeny virus particles. Silibinin but not SIL inhibited NF-κB- and IFN-B-dependent transcription in Huh7 cells. However, both mixtures inhibited T cell proliferation to similar degrees. These data underscore the differences and similarities between the intravenous and oral formulations of silibinin, which could influence the clinical effects of this mixture on patients with chronic liver diseases.

IL28B SNP rs8099917 is strongly associated with pegylated interferon-α and ribavirin therapy treatment failure in HCV/HIV-1 coinfected patients

Recent genome-wide association studies report that the SNP rs8099917, located 8.9 kb upstream of the start codon of IL28B, is associated with both disease chronicity and therapeutic response to pegIFN-α and RBV in patients infected with genotype 1 HCV. To determine the effect of rs8099917 variation on the response of HCV to therapy, we genotyped this variant in a cohort of 160 HCV/HIV-1 coinfected patients in our clinic unit who received combined peg-IFN-α/RBV therapy. The rs8099917 T/G or G/G genotypes were observed in 56 patients (35%). Treatment failure occurred in 80% of G-allele carriers versus 48% of non-carriers (P<0.0001). This result reveals that the G allele was strongly associated with treatment failure in this patient cohort. Importantly, a highly significant association was found between the G-allele and response to therapy in HCV genotype 1-infected patients (P<0.0001) but not in HCV genotype 3-infected patients. Multivariate analysis (odds ratio; 95% confidence interval; P value) indicated that the rs8099917 TT genotype was a strong predictor of treatment success (5.83; 1.26-26.92; P = 0.021), independent of baseline plasma HCV-RNA load less than 500 000 IU/ml (4.85; 1.18-19.95; P = 0.025) and absence of advanced liver fibrosis (5.24; 1.20-22.91; P = 0.025). These results reveal the high prevalence of the rs8099917 G allele in HCV/HIV-1 coinfected patients as well as its strong association with treatment failure in HCV genotype 1-infected patients. rs8099917 SNP genotyping may be a valid pre-treatment predictor of which patients are likely to respond to treatment in this group of difficult-to-treat HCV/HIV-infected patients.

Adjuvant therapy used in conjunction with combination therapy for chronic hepatitis C improves sustained virus response rates in genotype 1 patients

Combination treatment with pegylated interferon (Peg-IFN) and ribavirin remains the gold standard in the treatment of chronic hepatitis C. This therapy is limited by many side-effects including anaemia, neutropenia and reduced quality of life. The use of adjuvant agents to reduce the frequency of dose reductions because of haematological side-effects has been proven to be effective but there are few reports of what effect the use of these adjuvant therapies is having on sustained virological response (SVR). The aim of the study was to assess the clinical impact on sustained virological response of adjuvant therapies during combination therapy with Peg-IFN and ribavirin for chronic hepatitis C. A total of 132 patients, 96 males, were included in the study. The overall SVR was 66.7%, with 50% of genotype 1/4/6 (n = 27/54) patients achieving SVR and 78.2% of genotypes 2/3. The overall SVR of the treatment naïve patients (83/121) was 68.6%. Fifty-one of these patients were genotype 1 with 49.0% (25/51) of this group achieving SVR. The genotype 2/3 group of treatment naïve patients reached an SVR of 82.9% (58/70). Adjuvant therapy was used in 57 patients (43.8%). With the use of supportive adjuvant therapy, we achieved an overall SVR of 66.7% and in treatment naïve patients 68.6%. In genotype 1 patients, SVR rates of up to 46% have been reported in previous studies without the use of erythropoietin and granulocyte colony stimulating factor. We have demonstrated the SVR for genotype 1 can be improved to 50% overall.

IL28B is associated with response to chronic hepatitis C interferon-alpha and ribavirin therapy

Hepatitis C virus (HCV) infects 3% of the world's population. Treatment of chronic HCV consists of a combination of PEGylated interferon-alpha (PEG-IFN-alpha) and ribavirin (RBV). To identify genetic variants associated with HCV treatment response, we conducted a genome-wide association study of sustained virological response (SVR) to PEG-IFN-alpha/RBV combination therapy in 293 Australian individuals with genotype 1 chronic hepatitis C, with validation in an independent replication cohort consisting of 555 individuals. We report an association to SVR within the gene region encoding interleukin 28B (IL28B, also called IFNlambda3; rs8099917 combined P = 9.25 x 10(-9), OR = 1.98, 95% CI = 1.57-2.52). IL28B contributes to viral resistance and is known to be upregulated by interferons and by RNA virus infection. These data suggest that host genetics may be useful for the prediction of drug response, and they also support the investigation of the role of IL28B in the treatment of HCV and in other diseases treated with IFN-alpha.

Gene expression profile of Huh-7 cells expressing hepatitis C virus genotype 1b or 3a core proteins

BACKGROUND

The liver disease expression in chronic hepatitis C patients is variable and may partially depend on the sequence of the infecting viral genotype.

AIM

To identify some hepatitis C virus (HCV) genotype-specific virus-host interactions potentially leading to clinically significant consequences.

METHODS

We compared the gene expression profile of Huh-7 cells transiently expressing the core protein of HCV genotype 1b and 3a using microarray technology.

RESULTS

Thirty-two genes were overexpressed in Huh-7 transfected with the HCV genotype 1b core protein and 57 genes in cells transfected with the genotype 3a core protein. On the other hand, we found 20 genes downregulated by core 1b and 31 genes by core 3a. These included genes involved in lipid transport and metabolism, cell cycle, immune response and insulin signalling.

CONCLUSION

The expression of HCV core proteins of different genotypes leads to a specific gene expression profile. This may account for the variable disease expression associated with HCV infection.

Randomized trial of high-dose interferon-alpha-2b combined with ribavirin in patients with chronic hepatitis C: Correlation between amino acid substitutions in the core/NS5A region and virological response to interferon therapy

The aim of this study was to compare the efficacy of high-dose interferon (IFN)-alpha-2b with standard dose of IFN-alpha-2b in combination with ribavirin (RBV) for patients with chronic hepatitis C virus (HCV) infection, and to investigate the predictive factors associated with virological response. Two hundred Japanese patients with high HCV viral load (>100 KIU/ml) were randomized to 6 or 10 mega units (MU) of 24-week IFN-alpha-2b with RBV. Predictive factors were investigated; including pretreatment amino acid (aa) sequences of the core region and the IFN-sensitive determining region (ISDR). The sustained virological response rate was not different in the two groups (24% vs. 30%) but the incidence of depression was significantly higher in the 10 MU group than 6 MU group (7% vs. 0%, P = 0.02). Younger age (<60) and HCV genotype (2a/b) were significant predictors of sustained virological response. In patients infected with genotype 1b, substitutions of core aa 70 and/or 91 were predictive for non-virological response (P < 0.001), and substitutions in the ISDR was observed frequently in virological responders. Early viral kinetics study showed that serum HCV core antigen decreased more slowly in both patients with aa 70 and/or 91 substitutions in the core and with absence of substitutions in the ISDR. In conclusion, the use of a higher dose of IFN-alpha-2b in combination with RBV did not improve virological response but resulted in higher incidence of depression. Amino acid substitutions in the core and ISDR are predictive of virological response to the therapy in patients with genotype 1b and high viral load.

Optimizing the current therapy for chronic hepatitis C virus: peginterferon and ribavirin dosing and the utility of growth factors

Achieving a sustained virologic response depends on the patient achieving three sequential independent milestones: virologic response, maintaining this response throughout treatment, and not relapsing after treatment has been completed. The ability to achieve these milestones depends on the doses of interferon/peginterferon and ribavirin used and on whether treatment with these medications is adjusted, interrupted, or prematurely discontinued in response to adverse events. This review discusses strategies to optimize peginterferon and ribavirin dosing and the impact that growth factors may have on the ability to achieve a sustained virologic response.

A novel unsupervised method to identify genes important in the anti-viral response: application to interferon/ribavirin in hepatitis C patients

Background

Treating hepatitis C with interferon/ribavirin results in a varied response in terms of decrease in viral titer and ultimate outcome. Marked responders have a sharp decline in viral titer within a few days of treatment initiation, whereas in other patients there is no effect on the virus (poor responders). Previous studies have shown that combination therapy modifies expression of hundreds of genes in vitro and in vivo. However, identifying which, if any, of these genes have a role in viral clearance remains challenging.

Aims

The goal of this paper is to link viral levels with gene expression and thereby identify genes that may be responsible for early decrease in viral titer.

Methods

Microarrays were performed on RNA isolated from PBMC of patients undergoing interferon/ribavirin therapy. Samples were collected at pre-treatment (day 0), and 1, 2, 7, 14 and 28 days after initiating treatment. A novel method was applied to identify genes that are linked to a decrease in viral titer during interferon/ribavirin treatment. The method uses the relationship between inter-patient gene expression based proximities and inter-patient viral titer based proximities to define the association between microarray gene expression measurements of each gene and viral-titer measurements.

Results

We detected 36 unique genes whose expressions provide a clustering of patients that resembles viral titer based clustering of patients. These genes include IRF7, MX1, OASL and OAS2, viperin and many ISG's of unknown function.

Conclusion

The genes identified by this method appear to play a major role in the reduction of hepatitis C virus during the early phase of treatment. The method has broad utility and can be used to analyze response to any group of factors influencing biological outcome such as antiviral drugs or anti-cancer agents where microarray data are available.

Inhibition of T-cell inflammatory cytokines, hepatocyte NF-kappaB signaling, and HCV infection by standardized Silymarin

BACKGROUND & AIMS

Chronic hepatitis C is a serious global medical problem necessitating effective treatment. Because standard of care with pegylated interferon plus ribavirin therapy is costly, has significant side effects, and fails to cure about half of all infections, many patients seek complementary and alternative medicine to improve their health, such as Silymarin, derived from milk thistle (Silybum marianum). Milk thistle's clinical benefits for chronic hepatitis C are unsettled due to variability in standardization of the herbal product.

METHODS

In the current study, we focused on the anti-inflammatory and antiviral properties of a standardized Silymarin extract (MK-001).

RESULTS

MK-001 inhibited expression of tumor necrosis factor-alpha in anti-CD3 stimulated human peripheral blood mononuclear cells and nuclear factor kappa B-dependent transcription in human hepatoma Huh7 cells. Moreover, MK-001 dose dependently inhibited infection of Huh7 and Huh7.5.1 cells by JFH-1 virus. MK-001 displayed both prophylactic and therapeutic effects against HCV infection, and when combined with interferon-alpha, inhibited HCV replication more than interferon-alpha alone. Commercial preparations of Silymarin also displayed antiviral activity, although the effects were not as potent as MK-001. Antiviral effects of the extract were attributable in part to induction of Stat1 phosphorylation, while interferon-independent mechanisms were suggested when the extract was biochemically fractionated by high-performance liquid chromatography. Silybin A, silybin B, and isosilybin A, isosilybin B elicited the strongest anti-NF-kappaB and anti-HCV actions. These effects were independent of MK-001-induced cytotoxicity.

CONCLUSIONS

The data indicate that Silymarin exerts anti-inflammatory and antiviral effects, and suggest that complementary and alternative medicine-based approaches may assist in the management of patients with chronic hepatitis C.

Interferon-alpha therapy within the first year after acute hepatitis C infection in hemodialysis patients: efficacy and tolerance

BACKGROUND

Interferon monotherapy significantly reduces the chronicity rate of acute hepatitis C in nonuremic patients. In this clinical study, we evaluated the efficacy and tolerance of interferon-alpha therapy for acute hepatitis C in hemodialysis patients.

METHODS

Patients with acute hepatitis C, established on the basis of seroconversion to anti-hepatitis C virus and the presence of hepatitis C virus RNA, received a low dose of interferon-alpha (3 MU three times per week) for 12 months or a high dose (5 MU three times per week, preceded by a daily induction dose) for 6 months. Response to treatment was defined as undetectable hepatitis C virus RNA at the end of treatment and sustained virological response was defined as persistent negative hepatitis C virus RNA 6 months after the end of treatment.

RESULTS

Twenty-three patients were treated, 16 with a low dose of interferon-alpha and seven with a high dose. At the end of treatment, hepatitis C virus RNA was undetectable in 16/23 patients (70%). Of these, 6/23 patients (26%) relapsed and 10/23 (43%) maintained a sustained virological response (38% in lower doses vs. 57% in higher doses). Treatment was well tolerated and only three patients discontinued therapy (13%).

CONCLUSION

Interferon-alpha within the first year after acute hepatitis C in hemodialysis patients was found to be safe and effective, inducing a sustained virological response in 43% of cases. This study supports the routine indication of acute hepatitis C treatment with interferon-alpha for hemodialysis patients, and higher doses administered for a shorter period of time should be tried according to the tolerance of the patients.

High dose daily interferon-alpha induction and secondary adjunction of ribavirin in treatment-naive patients with chronic hepatitis C

OBJECTIVES

To evaluate in naive patients with chronic hepatitis C 1- the efficacy and safety of one month interferon alpha (IFN-alpha) induction regimen; 2- the potential virological benefit of a secondary adjunction of ribavirin among HCV RNA negative patients after 20 weeks of IFN therapy, with or without an initial 4-week IFN induction.

MATERIAL AND METHODS

151 naive HCV-RNA positive patients presenting with biopsy- proven chronic hepatitis C and elevated ALT were randomised in a 2: 1 ratio in two arms: IFN-alpha 3 MU thrice a week (tiw) for 24 weeks (non-induced patients); IFN-alpha 6 MU daily for two weeks, then 3 MU daily for two weeks then 3 MU tiw for 20 weeks (induced patients). At week 24, HCV-RNA negative patients were randomised to receive in addition or not ribavirin 1-1.2 g daily for 24 additional weeks. Induction efficacy was assessed on the early viral response (EVR) defined as undetectable HCV RNA at week 4 then week 20. Ribavirin efficacy was assessed on the proportion of maintained complete response until the end of follow-up, 24 weeks after discontinuation of treatment. Data were analysed on an intent-to-treat basis.

RESULTS

Efficacy of IFN-alpha induction: 104 patients were randomised to the non-induction group, 47 to the induction group. Gender, age, genotype distribution and HCV viral load at baseline did not differ significantly between the two groups. There was one treatment discontinuation because of adverse events in induced patients versus four in non-induced patients (P > 0.05). The 4 week EVR was significantly greater in induced patients in patients with HCV genotype 1, 4 or 5 (47% vs 12%, P=0.0002) only. There was no impact of induction in patients with HCV genotype 2 or 3. Efficacy of ribavirin: at week 24, 28 and 26 HCV-RNA negative patients were randomised to addition of ribavirin or not, respectively. Patients randomised to secondary additive ribavirin were more often HCV-RNA negative at the end of follow-up than patients treated with IFN-alpha alone: 18/28 (64%) vs 10/26 (39%); P=0.06. Among patients randomised to bitherapy, the relapse rate was significantly lower in patients with genotype 2 or 3 (0/12 vs 6/13, P=0.01) and not in those with genotype 1, 4 or 5 (5/11 vs 3/6, P=0.99).

CONCLUSION

A 4 week IFN-alpha induction significantly increases the EVR rate in patients with HCV genotype 1, 4 or 5. Late secondary adjunction of ribavirin to IFN-alpha for 6 months in HCV-RNA negative patients after 6 months of IFN-alpha significantly decreases the relapse rate in patients with HCV genotype 2 or 3, but not in patients with genotypes 1, 4 or 5.

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.

Recombinant interferon alpha treatment decreases heart rate variability indices and impairs exercise tolerance in patients with chronic hepatitis

Complications of interferon (IFN) therapy include cardiac arrhythmias, impaired cardiac function and myocardial ischemia. Decreased heart rate variability (HRV) indices, impaired exercise tolerance and decreased left ventricular (LV) function are related to unfavorable outcome of heart disease. To investigate the effect of IFN therapy on HRV, exercise tolerance and cardiac function, 24-h ambulatory electrocardiographic monitoring (AECG), two-dimensional echocardiography, and exercise treadmill testing (ETT) was performed in 9 patients (age 56 +/- 9 years-old) with chronic hepatitis and without underlying heart disease before and after treatment with IFN (recombinant alpha 2b; 10 x 10(6) U/day for 4 weeks). HRV parameters consisted of standard deviation of RR interval (sdNN, ms), SDANN (ms), S.D. index (ms), rMSSD (ms), pNN50 (%) and frequency analysis of heart rate spectrum resulted in low (ms, 0.04-0.15 Hz), high (ms, 0.15-0.40 Hz) and total (ms, 0.01-1.00 Hz) frequency components. Ischemia was not detected by AECG or ETT, and LV function was normal after INF treatment in all patients. However, INF treatment resulted in a decrease in exercise tolerance time (449 +/- 94 s vs. 329 +/- 67 s, P < 0.05) and a decrease in several HRV parameters (S.D. index, 42 +/- 5 ms vs. 37 +/- 9 ms; rMSSD, 22 +/- 5 ms vs. 19 +/- 4 ms; pNN50, 4 +/- 3% vs. 2 +/- 1%; P < 0.05). Further, patients treated with INF tended to have a lower sdNN and total frequency spectra, although this difference did not reach the level of statistical significance. These data suggest that the arrhythmogenic effect of INF may be mediated by decreases in HRV and impairment of exercise tolerance even in patients without overt heart diseases. Further, INF therapy may be contraindicated in patients with predisposing severe cardiac disorders, including arrhythmias, ischemia and decreased LV function.

High-dose interferon-α2b induction therapy in combination with ribavirin for treatment of chronic hepatitis C in patients with non-response or relapse after interferon-α monotherapy

AIM: To evaluate the daily high-dose induction therapy with interferon-α2b (IFN-α2b) in combination with ribavirin for the treatment of patients who failed with interferon monotherapy and had a relapse, based on the assumption that the viral burden would decline faster, thus increasing the likelihood of higher response rates in this difficult-to-treat patient group.

METHODS: Seventy patients were enrolled in this study. Treatment was started with 10 MU IFN-α2b daily for 3 wk, followed by IFN-α2b 5 MU/TIW in combination with ribavirin (1 000-1 200 mg/d) for 21 wk. In case of a negative HCV RNA PCR, treatment was continued until wk 48 (IFN-α2b 3 MU/TIW+1 000-1 200 mg ribavirin/daily).

RESULTS: The dose of IFN-α2b or ribavirin was reduced in 16% of patients because of hematologic side effects, and treatment was discontinued in 7% of patients. An early viral response (EVR) was achieved in 60% of patients. Fifty percent of all patients achieved an end-of-treatment response (EOT) and 40% obtained a sustained viral response (SVR). Patients with no response had a significantly lower response rate than those with a former relapse (SVR 30% vs 53%; P = 0.049). Furthermore, lower response rates were observed in patients infected with genotype 1a/b than in patients with non-1-genotype (SVR 28% vs 74%; P = 0.001). As a significant predictive factor for a sustained response, a rapid initial decline of HCV RNA could be identified. No patient achieving a negative HCV-RNA PCR at wk 18 or later eventually eliminated the virus.

CONCLUSION: Daily high-dose induction therapy with interferon-α2b is well tolerated and effective for the treatment of non-responders and relapsers, when interferon monotherapy fails. A fast decline of viral load during the first 12 wk is strongly associated with a sustained viral response.

A decade of trials of interferon-alpha for chronic hepatitis C. A meta-regression analysis

The most relevant randomized controlled trials of interferon-alpha (IFN) for naive patients with chronic hepatitis C (CHC) published in a decade, just before appearance of pegylated IFN trials in 2000, were included in this paper. Its purpose is to review the relationship between sustained biochemical response in active versus control group versus usual clinical variables as IFN regimens, cirrhosis, genotype and versus less frequently addressed variables as funding, methodological quality or location of principal author. Meta-analysis estimates of global treatment effect varied according to trial design: group 1=IFN versus placebo/no treatment, 32 RCTs, 2499 pts, OR 9.5 (6.3-14.2); group 2a=comparison of IFN schedules, 43 RCTs, 7454 pts, OR 1.6 (1.4-1.9); group 2b=IFN+other drugs versus standard IFN, 30 RCTs, 4737 pts, OR 2.0 (1.6-2.6). Fixed effects (arm-level) meta-regression on the complete data set (171 arms, 10,580 pts) revealed that sustained response was most likely in experimental arms of IFN+ribavirin or other drugs (OR 2.4), arms using yearly schedule (OR 2.0), trial principal author from Asia (OR 1.7), trial sample size >200 (OR 1.4) and arms enrolling less than 50% of cirrhotics (OR 1.3). Moreover, focus was on some significant interactions too, as the effect of trial's quality interacting to the recorded funding (more benefit if no-profit, less if for-profit) and the effect of trial funding interacting to the location of first author (more benefit if from Asia). Three main effects (experimental arm, cirrhosis, funding) and one interaction (funding*location of principal author) explained 31% of between study variability in a random-effect meta-regression. In a subgroup analysis on a data set including available information on HCV genotype (93 arms, around 7000 pts), meta-regression revealed that genotype 1 or 4 less than 50% per arm and specialistic journal were significant predictors of either biochemical (transaminases) or virological (HCV-RNA) sustained response, in a model including the same main effects identified in the complete data set analysis. Finally, although mostly captured by different IFN regimens along time, heterogeneity of effect in a large set of (not-pegylated) IFN trials was also explained by HCV genotype and variables of quality and reporting, such as trial's principal author from Asia.

Antiviral action of ribavirin in chronic hepatitis C

BACKGROUND & AIMS

In the patients with chronic hepatitis C, the addition of ribavirin to interferon (IFN)-alpha significantly increases the virologic responses. Our aim was to assess the antiviral action of ribavirin on hepatitis C virus (HCV) as a function of ribavirin pharmacokinetics and to evaluate the influence of this antiviral effect on IFN-alpha efficacy.

METHODS

Forty-five patients with chronic hepatitis C (genotype 1b) received various schedules of IFN-alpha and/or ribavirin administration. Frequent blood sampling was performed for HCV RNA kinetics and ribavirin pharmacokinetics assessment.

RESULTS

Ribavirin monotherapy induced a significant, moderate, early, and transient viral load decrease in approximately half of the patients. The occurrence of this effect was associated with longer ribavirin clearance half-lives and higher serum ribavirin concentrations. Ribavirin antiviral effect partly reduced the rebound preceding the second IFN-alpha injection in patients receiving standard IFN-alpha 3 times per week plus ribavirin. The magnitude of the rebound was inversely related to ribavirin concentrations. These patients subsequently experienced a slow, but significant, second slope of viral decrease and cleared HCV RNA. The addition of ribavirin to daily IFN-alpha monotherapy did not have any impact on the second phase of viral decline.

CONCLUSIONS

Ribavirin exerts a significant, moderate, and transient antiviral effect in a significant proportion of patients with chronic hepatitis C. The antiviral effect of ribavirin correlates with ribavirin pharmacokinetics and is partly responsible for the improved efficacy of the combination of standard IFN-alpha and ribavirin compared with IFN-alpha monotherapy by increasing the incidence of the initial response.

First-line therapy with daily versus thrice-weekly interferon alfa-2b plus ribavirin for chronic hepatitis C

OBJECTIVES

Combination therapy with interferon and ribavirin is the most effective treatment for chronic hepatitis C today. Before pegylated interferons became available, higher and more frequent doses of interferon were expected to be more effective than the standard regimen of three million units thrice weekly. In fact, daily dosing is still proposed for non-pegylated interferon. The aim of this study was to compare the efficacy and safety of daily versus thrice-weekly interferon alfa-2b in combination with ribavirin as first-line treatment of chronic hepatitis C.

METHODS

A total of 116 treatment-naive patients were randomised to receive either interferon alfa-2b three million units daily or thrice-weekly in combination with ribavirin for 24 weeks. Patients with hepatitis C virus (HCV) genotype 1 who were HCV-RNA negative at 24 weeks continued treatment with thrice-weekly interferon plus ribavirin for another 24 weeks. Sustained virological response was defined as an undetectable HCV-RNA level 24 weeks after treatment was completed (end of follow-up).

RESULTS

In an intention-to-treat analysis, HCV-RNA was undetectable at the end of treatment in 71% and 74% of patients treated with daily and thrice-weekly interferon, respectively. At the end of follow-up, HCV-RNA was undetectable in 47% and 57% of patients treated with daily and thrice-weekly interferon, respectively. Sustained virological response rates were almost twice as high in patients with genotypes 2 and 3 as in patients with genotype 1 but were not different between treatment groups.

CONCLUSIONS

This study could not show any difference between daily and thrice-weekly standard interferon plus ribavirin in achieving end-of-treatment and sustained virological responses in chronic hepatitis C.

Daily induction combination treatment with alpha 2b interferon and ribavirin or standard combination treatment in naive chronic hepatitis C patients. A multicentre randomized controlled trial

The standard treatment for patients with chronic hepatitis C is a 6-12-month combination therapy with interferon alpha and ribavirin. Induction treatment could result in a faster early decline of the hepatitis C virus (HCV) load and a better response rate. Naive chronically infected HCV patients (n = 454) were randomized into two arms to receive either induction treatment with interferon alpha 2b 5 million units (MU) subcutaneously (s.c.) daily during a period of 8 weeks (arm A); or treatment with interferon alpha 2b 5 MU s.c. three times a week (TIW) for a period of 8 weeks (arm B). After week 8, interferon treatment in both arms was 3 MU s.c. TIW for a total period of 12 months. In both arms, ribavirin (1000-1200 mg orally per day) was added at week 4. Induction treatment resulted in a higher virological response at week 8 of treatment (66%vs 47%; P < 0.01). However, response at the end of treatment and at 6 months follow-up was not different (53%vs 50%, 41%vs 33%). The occurrence of adverse events and the drop-out rate were similar in both arms. Although an early virological response is observed more frequently in the induction treatment, end of treatment response and sustained responses did not differ.

Comparative study of the efficacy of an induction dose of interferon-alpha2b with ribavirin compared with standard combined treatment in naive patients with chronic hepatitis C

The efficacy and secondary effects of an induction dose of interferon-alpha2b (IFN-alpha2b) with ribavirin compared with standard combined treatment in naive patients with chronic hepatitis C infection were compared. A prospective study was undertaken between March 1998 and November 2001 in which 84 Spanish hospitals took part. Six hundred and fourteen naive patients (age range 18-65 years) diagnosed with chronic hepatitis C virus (HCV) infection and without cirrhosis or co-infection by other viruses, were included. Patients were divided into two groups. Group A (n = 304) received induction treatment with a daily dose of 5 MU of IFN-alpha2b for 4 weeks, followed by 5 MU three times a week with ribavirin (1000-1200 mg/day, according to weight) until completing 1 year of treatment. Group B (n = 310) received the standard dose of IFN-alpha2b of 3 MU three times per week for 48 weeks together with ribavirin (1000-1200 mg/day, according to weight). Both groups were completely comparable according to age, gender, body weight, transaminase levels, genotype, viral load and hepatic inflammatory activity (Knodell Index). No control group was included for ethical reasons. Pegylated interferon was not available at the time of the study. Serum baseline samples were collected for the determination of genotype. Samples were also collected at baseline, weeks 4, 12, 24, 48 and 72, in order to detect and quantify HCV-RNA. The efficacy of treatment was evaluated by means of sustained viral response (SVR) characterized by persistent negativity of HCV-RNA at the end of the follow-up period. At week 4, the response to treatment was greater in group A (49.6%) compared with group B (34.5%) (P = 0.0002), and was maintained until week 12 (64.1% compared with 55.8% respectively) (P = 0.03). These differences disappeared at week 24, when group A (69%) was compared with group B (65%) (NS). At week 48, the response rate for group A was 50.6% compared with group B 47.4% (NS), and at week 72, the SVR in group A was 46% compared with 40.3% for group B (NS). The global SVR was 43.1%. On analysing the response to treatment according to genotype and viral load, we found that the induction treatment was slightly superior in patients with genotype 1 and an elevated viral load (>2 x 10(6) copies/ml). They achieved a SVR in group A of 39.1% compared with 25.5% in group B (P < 0.05). However, this slight improvement obtained in group A, was achieved at the expense of a greater percentage of dropouts compared with group B (6.4% vs 2.2%, P < 0.01); a greater rate of side effects (58.5 vs 36.7%, P < 0.05) and also a greater percentage of neutropenia (3.1% vs 0.9%, P < 0.05). The induction treatment presented a better initial response, but this was not maintained at the end of treatment, and did not improve the results obtained with the standard treatment. Although the patients with genotype 1 and elevated viral load had a better response with the induction treatment, this was accompanied by a greater percentage of dropouts and secondary effects. It would be interesting to repeat this type of study in the future, using pegylated interferon.

Infection with chronic hepatitis C virus and liver transplantation: a role for interferon therapy before transplantation

An analysis of the National Institute of Diabetes and Digestive and Kidney Diseases Liver Transplant Registry data shows that the greater the viral load at the time of transplantation, the more rapidly clinically evident posttransplantation hepatitis C virus (HCV) disease recurs. These data suggest that aggressive pretransplantation treatment of HCV might delay recurrent posttransplantation HCV disease and enhance posttransplantation survival. We have taken an aggressive approach to treating HCV infection pretransplantation with the use of high-dose (5 MU) daily interferon alpha(2b) in an effort to clear the virus before transplantation. A total of 27 patients with HCV-induced cirrhosis were seen and underwent transplantation at Loyola University Medical Center (Maywood, IL) between February 1997 and December 2001. There were 22 men and five women, with a mean age of 56 +/- 2 years. The majority had genotype 1 disease (67%). Of the 27 patients, 7 had a baseline platelet count <50,000/mm(3) and were excluded from interferon therapy. The remaining 20 were treated for a mean of 14 +/- 2.5 (range, 0.5 to 33.5) months before orthotopic liver transplantation (OLT). Twelve (60%) responded to the therapy with serologic clearance of HCV before OLT. The mean time from initiation of therapy to the first negative qualitative polymerase chain reaction was 4.5 +/- 1.5 (range, 0.5 to 12) months. Four of the 12 patients in whom the virus cleared did not have evidence of HCV recurrence after OLT, representing 20% of those treated and 33% of those who had HCV clearance before OLT. The duration of post-OLT freedom from HCV infection in these individuals has been 33.6 +/- 11.3 (range, 0 to 47.4) months. These data suggest that with careful supervision, cirrhotic patients can tolerate high-dose interferon. In addition, a viral clearance can be achieved in a significant number of cirrhotic patients with high-dose interferon. One third of patients, in whom the HCV cleared before OLT, did not have evidence of disease recurrence after OLT. It is thus anticipated that with early and aggressive pre-OLT HCV therapy, possibly with the use of pegylated interferon, even better results may be obtained.

Sustained response to combination therapy in patients with chronic hepatitis C who failed to respond to interferon

BACKGROUND/AIMS

The best treatment for chronic hepatitis C patients who do not respond to interferon is still unknown. Reported rates of response to treatment vary as the result of heterogeneous definitions of non-responders and small study size.

METHODS

One hundred nineteen hepatitis C virus (HCV) RNA-positive non-responders to high-dose interferon monotherapy received alpha-interferon, 5 MU tiw plus oral ribavirin, 1000-1200 mg/day for 48 weeks (Group A, n=74) or alpha-interferon, 5 MU daily for 4 weeks, followed by 5 MU tiw plus oral ribavirin, 1000-1200 mg/day for 44 weeks (Group B, n=45) according to the Institution where they were followed. Persistently normal alanine aminotransferase and negative HCV RNA up to 72 weeks from treatment onset defined a sustained response.

RESULTS

Eighteen patients discontinued treatment (13 developed anemia, two mucositis, one granulocytopenia; two were dropouts), none for serious adverse events. There were 24 (20%) sustained responders, with similar final response rates in Groups A and B. Sustained response was more frequent in patients aged </=40 years (36% vs. 13%; P=0.006) and in those with non-1 genotype (44% vs. 14%; P=0.002). Among genotype 1 patients, the younger ones showed higher response rates (32% vs. 7%; P=0.005). Compared with patients harboring non-1 genotypes, the odds ratio of being a non-responder was 1.68 (confidence interval (CI): 0.53-5.37; P=0.381) in younger genotype 1 patients and 9.53 (CI: 2.84-32; P<0.001) in older genotype 1 patients.

CONCLUSIONS

Chronic hepatitis C patients who are non-responders to interferon monotherapy and infected by non-1 genotypes should undergo re-treatment with combination therapy. Treatment should be extended to younger genotype 1 patients who are more susceptible to liver disease worsening because of longer life expectancy and have a higher probability of being long lasting responders than their older counterparts.

Mathematical modeling of viral kinetics: a tool to understand and optimize therapy

One theme that continues to emerge from these studies is the relevance and need for a strong IFN effectiveness. In the prediction studies, the importance of IFN effectiveness for eventual clearance of the virus is present. In the study by Layden et al, the relevance of the viral load at the end of the first phase and IFN effectiveness, to the subsequent second-phase viral decline, is discussed. In the recently developed triphasic model by Bergmann et al, it is illustrated how, theoretically, the viral load at the end of the first phase could impact the second-phase viral decline and eventual clearance of the virus. And, in the investigation into the difference in viral dynamics between African Americans and Caucasians, it appears that a strong effectiveness and first-phase log drop is crucial for virus eradication. More work needs to be completed to understand better why the effectiveness is so crucial for elimination of the virus, and why the effectiveness varies so significantly from one person to another, or from one genotype to another. In a rather short time, the study of viral kinetics has improved our understanding of HCV infection, especially in relation to treatment response. Information has been gleaned on the rapid turnover and clearance rate of the virus, the mode of action of IFN, and the dose-dependence of IFN in inhibiting viral production. Such information has been used to challenge the way we treat patients, understand the difference between nonresponders and responders, gain insight into possible mechanisms of treatment resistance, and predict treatment response. As newer drugs emerge, viral kinetic studies should be able to shed light on the dose-dependent efficacy and mode of action of these newer forms of therapy. The use of kinetics needs to be extended to other areas, such as the study and treatment of acute HCV infection as well as following liver transplantation (see article by Drs. Pawlotsky and Rosen). If the past is any indication of the usefulness of mathematical modeling and kinetics in the study of viruses, continued employment of these tools will only prove beneficial.

Efficacy of induction therapy with high-dose interferon for patients with hemophilia and human immunodeficiency virus-hepatitis C virus coinfection

To evaluate the efficacy of high-dose interferon (IFN) on human immunodeficiency virus (HIV) and hepatitis C virus (HCV) infection, 15 HIV-positive patients and 15 age-matched HIV-negative patients with hemophilia were treated with 9 million units (MU) of IFN-alpha2a daily for 2 weeks, followed by 9 MU of IFN-alpha2a 3 times/week for a further 22 weeks. At week 2, HIV RNA levels decreased from 7410+/-2190 to 320+/-130 copies/mL, and HCV RNA levels decreased from 390x10(3)+/-80x10(3) to 70x10(3)+/-30x10(3) copies/mL in the HIV-positive group and from 300x10(3)+/-80x10(3) to 10x10(3)+/-10x10(3) copies/mL in the HIV-negative group. HCV RNA was undetectable after treatment in 4 of 12 HIV-positive and 6 of 15 HIV-negative patients. IFN therapy was discontinued because of adverse effects in 3 HIV-positive patients. Induction therapy and the dose of IFN should be evaluated in combination therapy with IFN and ribavirin.

Evaluation of Loading Dose of IFN in HCV Patients: Prospective, Uncontrolled Study

Current treatment regimens with either long-term interferon (IFN) monotherapy or interferon-ribavirin combination achieve a sustained response of 6-21%. To improve the efficacy of IFN several strategies have been devised, including the use of higher doses of IFN, prolonged courses or pegylated IFN. Some recent reports have suggested that daily administration of IFN in the early phase of therapy (induction dose) may be more efficacious than the classic thrice-weekly regimen. There is no available data about the combination of induction dose regimen of IFN and ribavirin.

Our objective was to evaluate prospectively the efficacy and safety of a 5mu IFN induction dose in combination with ribavirin in HCV patients. End treatment response (ETR) was 36.7% of the 30 patients included in the study, while 81.1% ofresponders could remain viral negative for one year after discontinuation of treatment (sustained response). Though responders had higher pretreatment levels of viraemia and ALT, it was still without statistical signficance. Also, there was no statistical histological difference between both groups. There was a significant correlation between response rate and post induction viraemia level (p < 0.05) but no similar relation to post-induction ALT level. We conclude that induction dose regimen seems to have no effect on ETR but may improve sustained response. Also, post-induction viral load level is a good predictor for both ET and sustained responses.

Pilot study of interferon alpha high-dose induction therapy in combination with ribavirin for chronic hepatitis C in HIV-co-infected patients

Twenty-three HIV/hepatitis C virus (HCV)-co-infected patients received dose-escalated IFN-alpha (5 MIU/day) induction therapy for 10 weeks, followed by 36 weeks of thrice-weekly IFN-alpha treatment (5 MIU), both in combinations with ribavirin. Sustained HCV clearance was observed in three patients. Nine patients discontinued the study aas a result of adverse reactions such as anaemia, pancreatitis and depression. In HIV/HCV-co-infected patients, the therapeutic benefit of high-dose IFN-alpha therefore seems to be limited by its poor tolerability.

Pegylated interferons for the treatment of chronic hepatitis C infection

BACKGROUND

Interferon (IFN) alfa is a clinically effective therapy used in a wide range of viral infections and cell-proliferative disorders. Combination therapy with IFN alfa-2b and ribavirin is the current standard of care for the treatment of chronic hepatitis C (CHC) infection. However, standard IFN alfa has the drawbacks of a short serum half-life and rapid clearance. To overcome this problem, 2 pegylated forms of IFN have been developed and tested clinically.

OBJECTIVE

This article reviews the development and properties of pegylated IFN alfa-2b and pegylated IFN alfa-2a, and presents safety and efficacy data from recent clinical trials.

METHODS

Relevant clinical studies were identified through a MEDLINE search from 1966 through the present using the key words hepatitis C and interferon. Studies of the pegylated IFNs in humans were then selected.

RESULTS

Pegylated IFN alfa-2b is formed by covalent conjugation of a 12-kd mono-methoxy polyethylene glycol (PEG) molecule to IFN alfa-2b, and pegylated IFN alfa-2a by covalent conjugation of a 40-kd branched mono-methoxy PEG molecule to IFN alfa-2a. The 2 pegylated IFNs differ in the mixture of pegylation isomers resulting from their conjugation chemistry. Pegylated IFN alfa-2b has a prolonged serum half-life (40 hours) relative to standard IFN alfa-2b (7-9 hours). The greater polymer size of pegylated IFN alfa-2a acts to reduce glomerular filtration, markedly prolonging its serum half-life (72-96 hours) compared with standard IFN alfa-2a (6-9 hours). In clinical studies, once-weekly dosing of the pegylated IFNs was associated with a sustained virologic response in patients infected with hepatitis C virus (HCV). Once-weekly dosing with either of the pegylated IFNs was more effective than the respective thrice-weekly regimen of IFN alfa, with a comparable safety profile. The combination of once-weekly pegylated IFN and ribavirin effectively reduced HCV viral load and sustained viral suppression.

CONCLUSIONS

Once-weekly dosing with either pegylated IFN alfa-2b or pegylated IFN alfa-2a has been shown to produce significantly higher rates of viral eradication than standard thrice-weekly IFN alfa therapy without compromising safety. With respect to the treatment of CHC, the greatest anti-HCV efficacy has been achieved with the combination of once-weekly pegylated IFN and ribavirin.

Early viral clearance and sustained response in chronic hepatitis C: a controlled trial of interferon and ribavirin after high-dose interferon induction

High-dose induction with alpha-interferon induces early viral clearance of hepatitis C and combined with ribavirin enhances sustained response. We assess whether adding ribavirin after viral clearance obtained by alpha-interferon induction increased the rate of viral eradication.Forty-one naïve patients with chronic hepatitis C were randomised to receive, after 4 weeks of 10 mU daily of alpha-interferon (induction), 3 mU daily for 22 weeks and 3 mU thrice weekly for 26 weeks of either interferon alone (monotherapy) or interferon plus 1000-1200 mg daily of ribavirin (combination therapy). At the end of the induction phase, 23 (56%) subjects had cleared HCV-RNA. During therapy, breakthrough was observed in four patients on monotherapy, but never in patients on combination therapy. The rate of clearance of HCV-RNA was different between monotherapy and combination therapy at the end of treatment (40% vs. 76.1%, P=0.02) and at the end of follow-up (5% vs. 57.1%, P=0.001). Twelve of the 23 patients who cleared HCV-RNA during induction, but only one of the 18 still HCV-RNA-positive after 4 weeks of therapy, had a sustained response (52.2% vs. 5.6%, P=0.001). Clearance of HCV-RNA at 1 week had a high positive predictive value for sustained response in combination therapy (PPV=0.75), but not in monotherapy (PPV=0.33). Induction with high daily doses of alpha-interferon obtains suppression of hepatitis C in more than half of patients, but ribavirin is needed to maintain a sustained response. The rate of sustained response is a function of the time to HCV-RNA clearance. In patients not responding to induction therapy addition of ribavirin does not obtain a sustained virological response.

Induction therapy with consensus interferon (CIFN) does not improve sustained virologic response in chronic hepatitis C

In patients infected with hepatitis C virus (HCV) genotype 1, sustained viral response (SVR) averages 10-40% depending on treatment regime. It has been proposed that high dose daily interferon (IFN) therapy early in therapy (induction dosing) may enhance SVR. In the present study we examined this issue and also assessed whether one could predict SVR and non-SVR, based on viral kinetics during the first month of induction therapy. End of treatment response and SVR was determined in 173 HCV infected patients who were treated with different induction doses of consensus interferon (CIFN) for one month followed by 11 months of standard 9 microg of CIFN thrice weekly (TIW). The second phase decline slope was calculated by log-linear regression on weekly measurements of serum HCV RNA during the first 7-28 days of treatment; rapid viral response (RVR) during the first month of induction dosing was defined as a decline of > 0.3 log copies/mL/week. Overall, SVR occurred in 11% of genotype 1 infected patients and 41% of patients with nongenotype 1. High dose induction therapy did not increase the rate of SVR, in either genotype 1 or genotype 2/3 infected patients. No patient without a RVR during the first month had SVR, while SVR occurred in 55% of the patients with RVR. RVR was the best predictor of SVR using multivariate analysis. These results indicate that induction dosing with CIFN does not improve SVR rates. They also suggest that early viral kinetics during the first month of therapy can predict non-SVR and thus save a patient a year long treatment which is fraught with side-effects and significant cost.

Daily or three times per week interferon alpha-2b in combination with ribavirin or interferon alone for the treatment of patients with chronic hepatitis C not responding to previous interferon alone

BACKGROUND/AIMS

We compared the efficacy and safety of the combined therapy of daily interferon alpha-2b and ribavirin with those of interferon alpha-2b three times per week alone or in combination with ribavirin in non-responder patients with hepatitis C virus (HCV) infection.

METHODS

A total of 376 patients were randomly assigned to receive interferon alpha-2b (6 MU three times per week for 24 weeks followed by 3 MU three times per week for 24 weeks) alone (group A) or in combination with ribavirin for 48 weeks (group B), or daily interferon alpha-2b (3 MU per day for 24 weeks followed by 3 MU three times per week for 24 weeks) and ribavirin (group C).

RESULTS

After 24 weeks of therapy, HCV RNA was undetectable in 11.7, 24.0, and 37.8% for groups A, B, and C, respectively. Sustained virological response was more frequent in patients who received combination therapy with three times weekly interferon (20.9%) or daily interferon (26.0%) than in patients who received interferon alone (5.8%) (P<0.001). The predictive HCV parameters for sustained response were a low viral load on day 7 and a negative HCV RNA on week 12.

CONCLUSIONS

In conclusion, in non-responder patients with chronic hepatitis C, virological response with daily interferon and ribavirin, compared to interferon monotherapy, was significantly improved during treatment, although sustained virological response was similar for both combination therapies with ribavirin and three times a week or daily interferon.

High sustained response to daily dosing of interferon with ribavirin in chronic hepatitis C patients naïve to therapy

BACKGROUND

: Viral kinetics suggests that daily administration of alpha-interferon (IFN) will clear hepatitis C virus (HCV) RNA earlier and more frequently compared with standard t.i.w. To reduce the likelihood of viral replication, mutation and subsequent development of resistance, daily dosing with IFN may be appropriate. To determine the safety and efficacy of daily IFN with ribavirin in chronic HCV infection we performed a prospective study.

METHODS

: Thirty-five naïve adult HCV-positive patients (25 male/10 female) were treated with IFN-alpha2b; 5 MU daily for 2 weeks followed by 3 MU daily for 22 weeks and ribavirin 800-1200 mg/day depending on weight. Liver biopsy, performed in 25 patients, showed mild to moderate activity in 19 patients (76%) and severe activity in six patients (24%). Two patients showed staged IV fibrosis. Serotyping was performed in 29 patients by an enzyme immunoassay-based Murex assay. Type 3 was the predominant serotype, present in 14 cases. Hepatitis C virus RNA was measured by the Chiron bDNA assay.

RESULTS

: Mean baseline HCV-RNA level was 14.2 +/- 18.7 MEq/mL (median 6.09; range 0.2-92.5), which became undetectable in all but three patients at week 4. Normalization of alanine aminotransferase (ALT) at week 4 was seen in 27 patients. Three patients withdrew due to non-compliance. Thirty-two patients completed 24 weeks of therapy as per the protocol. At the end of treatment, the HCV-RNA level was negative in 29 of 32 patients (90.6%) and ALT was normal in 31 of 32 patients (97%). Sustained viral response at 6 months follow up was seen in 28 of 32 patients (88%). The ALT level was normal in 28 of 32 patients (88%).

CONCLUSION

: Daily administration of IFN with ribavirin is well tolerated in the majority of patients. There is rapid elimination of virus with normalization of ALT and a significantly high sustained viral response.

Daily or three times a week interferon alfa-2b in combination with ribavirin or interferon alone for the treatment of patients with chronic hepatitis C

BACKGROUND/AIMS

Data on hepatitis C virus (HCV) viral dynamics and on the effect of interferon in blocking virion production have suggested a rationale for daily administration of interferon in patients with chronic hepatitis C infection. We compared the efficacy and safety of daily interferon alfa-2b in combination with ribavirin with those of interferon alfa-2b three times a week alone or in combination with ribavirin.

METHODS

We randomly assigned 321 patients with chronic hepatitis C to receive standard-dose interferon alfa-2b alone or in combination with ribavirin for 48 weeks or daily interferon alfa-2b (3 million units per day for 12 weeks then 3 million units three times per week for 24 weeks) and ribavirin (36 week treatment).

RESULTS

The rate of sustained virologic response (defined as an undetectable serum HCV-RNA level 72 weeks after initiation of treatment) was higher in patients who received combination therapy with three times weekly interferon (51.7%) or daily interferon (46.1%) than in patients who received interferon alone (25%) (P=0.0001 and P=0.002, respectively). Independent predictive factors for sustained virologic response were combination therapy, weight, genotype and viral load. In conclusion, in patients with chronic hepatitis C, combination therapy with induction treatment (daily interferon for 12 weeks) and shorter duration of treatment was not different from combination therapy for 48 weeks without induction treatment.

CONCLUSIONS

Induction treatment with interferon for 12 weeks and combination therapy for a total duration of 36 weeks could therefore be cost effective.

Efficacy of daily induction dosing vs standard thrice weekly dosing of interferon-alpha2B for initial treatment of chronic hepatitis C

The aim of this study was to compare the effect on HCV RNA levels of using induction dosing with 5 MU interferon-alpha2b (IFN) given daily for four weeks followed by 5 MU IFN given three times a week (TIW) for 44 weeks vs standard noninduction TIW dosing of 5 MU IFN for 48 weeks. We randomly assigned 135 patients with chronic hepatitis C to induction therapy or noninduction therapy. After four weeks of therapy 17/65 (26.1%) patients had undetectable HCV viral levels in the induction group compared with 16/64 (25.0%) patients in the noninduction group. The mean HCV viral levels were similar at four weeks in patients who received induction and noninduction therapy. Mean HCV viral titers in the induction group increased from 4 to 16 weeks, whereas the mean viral titers in the noninduction group decreased during this time (P < 0.0001). HCV RNA was undetectable at the end of therapy in 17/66 (25.8%) in the induction group and 21/68 (30.9%) in the noninduction group. The sustained virologic response rate 24 weeks after the end of therapy was 14/67 (20.9%) in the induction group compared with 13/68 (19.1%) in the noninduction group. These results indicate that an initial four week period of daily interferon confers no benefit in the treatment of patients with chronic hepatitis C.

High-dose interferon alfa-2b and ribavirin in patients previously treated with interferon: results of a prospective, randomized, controlled trial

BACKGROUND

Kinetic studies have demonstrated a more rapid reduction in hepatitis C virus (HCV) RNA levels among patients taking high daily doses of interferon compared with those taking standard-dose interferon.

GOALS

To compare the efficacy and safety of high-dose interferon alfa-2b and ribavirin with standard-dose interferon alfa-2b and ribavirin in chronic hepatitis C patients previously treated with interferon.

STUDY

One hundred seven patients (30 interferon relapsers and 77 interferon nonresponders) were randomized to take either high-dose interferon alfa-2b in combination with ribavirin (group A) (consisting of 5 MU/d for 4 weeks, 5 MU three times weekly for 8 weeks, and then 3 MU three times weekly for 36 weeks) or standard-dose interferon alfa-2b and ribavirin (group B) for 48 weeks. Serum alanine transaminase (ALT), HCV RNA levels, and safety data were prospectively collected and compared during treatment and at week 24 of follow-up.

RESULTS

The mean serum ALT and HCV RNA levels, as well as the proportion of patients with genotype 1 and cirrhosis and who were African American, were similar in the two treatment groups at study entry. The rates of suppression of HCV RNA to undetectable levels at weeks 4, 12, and 48 were similar. In addition, the sustained virologic response rates at week 24 of follow-up were similar in groups A and B (29% vs. 39%, respectively, p = 0.277). Clinical variables that correlated with a sustained virologic response included a history of relapse to previous interferon therapy and non-1 HCV genotype ( p < 0.01).

CONCLUSIONS

Short-term, high-dose interferon alfa-2b and ribavirin failed to demonstrate a tangible benefit compared with standard-dose interferon alfa-2b and ribavirin. However, our study results and others suggest that standard-dose interferon and ribavirin for 48 weeks should be considered for selected patients who did not respond to previous interferon therapy.

Advances in therapy for chronic hepatitis C

Major advances in the treatment of chronic hepatitis C have been made during the last decade. The use of PEG-IFN in combination with ribavirin undoubtedly will become the new standard of care for patients with chronic hepatitis C. For the first time there will soon be a choice of medications for which long-term benefit will be the rule rather than the exception, as sustained virologic response rates rise above 50%. As the data mature from clinical trials with these new agents, clinicians will be able to refine and expand the indications for their use, hone the predictors of sustained response, and develop new paradigms to optimize treatment for chronic hepatitis C.

Management of interferon therapy nonresponders

Despite improvements in the therapies for chronic hepatitis C virus (HCV) over the past several years, many patients still fail to become hepatitis C virus ribonucleic acid (HCV-RNA) undetectable during treatment and are classified as nonresponders. Providing treatment recommendations for these patients requires that the likelihood of achieving any benefit from another course of therapy be balanced with the natural history of chronic HCV. The management of nonresponders represents the most challenging of all aspects in the care of patients with chronic HCV. Retreatment of interferon non-responders with interferon and ribavirin has yielded a long-term virologic benefit in only 10% to 25% of patients. The efficacy of peginterferon and peginterferon with ribavirin for nonresponders has yet to be defined.