Robust antiviral activity of R1626, a novel nucleoside analog: a randomized, placebo-controlled study in patients with chronic hepatitis C

The nucleoside analog R1479 is a potent and highly selective inhibitor of nonstructural protein 5B-directed hepatitis C virus (HCV) replication in vitro. R1626, a tri-isobutyl ester prodrug of R1479, was developed to increase bioavailability and improve antiviral activity. A multicenter, observer-blinded, randomized, placebo-controlled, multiple ascending dose, phase 1b study was designed to evaluate the safety, pharmacokinetics, and antiviral activity and to potentially identify the maximum tolerated dose of R1626 in patients with chronic hepatitis C. Forty-seven treatment-na?ve patients infected with HCV genotype 1 were treated with R1626 orally at doses of 500 mg, 1500 mg, 3000 mg, or 4500 mg or placebo twice daily for 14 days with 14 days of follow-up. Safety, tolerability, pharmacokinetics, and antiviral activity were assessed. Doses up to and including 3000 mg twice daily were well tolerated after 14 days of treatment. There was an increase in frequency of adverse events at the highest dose (4500 mg). Reversible mild to moderate hematological changes were observed with increasing doses. R1626 was efficiently converted to R1479, with dose-proportional pharmacokinetics observed over the entire dose range. The pharmacokinetics of R1479 were linear over the dose range evaluated. Dose-dependent and time-dependent reductions in HCV RNA were observed. Mean decreases (median; range) in viral load after 14 days of treatment with doses of 500, 1500, 3000, and 4500 mg were 0.32 (0.22; 0.01-0.71), 1.2 (0.8; 0.49-2.46), 2.6 (2.7; 1.27-3.93) and 3.7 (4.1; 2.15-4.39) log(10), respectively. No resistance to R1479 was observed after 14 days of treatment with R1626. Conclusion: These data support further studies of R1626 in combination with peginterferon alfa-2a and ribavirin for the treatment of patients with chronic HCV infection.     

Balapiravir plus peginterferon alfa-2a (40KD)/ribavirin in a randomized trial of hepatitis C genotype 1 patients

Introduction. Balapiravir (R1626, RG1626) is the prodrug of a nucleoside analogue inhibitor of the hepatitis C virus (HCV) RNA-dependent RNA polymerase (R1479, RG1479). This phase 2, double-blind international trial evaluated the optimal treatment regimen of balapiravir plus peginterferon alfa-2a (40KD)/ribavirin.Material and methods. Treatment-naive genotype 1 patients (N = 516) were randomized to one of seven treatment groups in which they received balapiravir 500, 1,000, or 1,500 mg twice daily, peginterferon alfa2a (40KD) 180 or 90 Mg/week and ribavirin 1,000/1,200 mg/day or peginterferon alfa-2a (40KD)/ribavirin. The planned treatment duration with balapiravir was reduced from 24 to 12 weeks due to safety concerns.Results. The percentage of patients with undetectable HCV RNA was consistently higher in all balapiravir groups from week 2 to 12. However, high rates of dose modifications and discontinuations of one/all study drugs compromised the efficacy assessment and resulted in similar sustained virological response rates in the balapiravir groups (range 32-50%) and the peginterferon alfa-2a (40KD)/ribavirin group (43%). Balapiravir was discontinued for safety reasons in 28-36% of patients (most often for lymphopenia) and the percentage of patients with serious adverse events (especially hematological, infection, ocular events) was dose related. Serious hematological adverse events (particularly neutropenia, lymphopenia) were more common in balapiravir recipients. Two deaths in the balapiravir/peginterferon alfa-2a/ribavirin combination groups were considered possibly related to study medication.Conclusion. Further development of balapiravir for the treatment of chronic hepatitis C has been halted because of the unacceptable benefit to risk ratio revealed in this study (www.ClinicalTrials.gov NCT 00517439).     

Peginterferon alfa-2a plus ribavirin for treating chronic hepatitis C virus infection: analysis of Mexican patients included in a multicenter international clinical trial

Treatment with polyethylene glycol-modified interferon alfa-2a (peginterferon) alone produces significantly higher sustained antiviral responses than treatment with interferon alfa-2a alone in patients with chronic hepatitis C virus (HCV) infection. We compared the efficacy and safety of peginterferon alfa-2a plus ribavirin, interferon alfa-2b plus ribavirin, and peginterferon alfa-2a alone in the initial treatment of chronic hepatitis C. Thirty-two patients were randomly assigned to treatment, and received at least one dose of medication consisting of 180 microg of peginterferon alfa-2a once weekly plus daily ribavirin (1,000 or 1,200 mg, depending on body weight) (n = 14), weekly peginterferon alfa-2a plus daily placebo (n = 6), or three million units of interferon alfa-2b thrice weekly plus daily ribavirin for 48 weeks (n = 12). More patients who received peginterferon alfa-2a plus ribavirin had a sustained virologic response (defined as the absence of detectable HCV RNA 24 weeks after cessation of therapy) than patients who received interferon alfa-2b plus ribavirin (7/14 vs. 4/12) or peginterferon alfa-2a plus placebo (0/6). The overall safety profiles of the three treatment regimens were similar. In conclusion, for patients with chronic hepatitis C, once-weekly peginterferon alfa-2a plus ribavirin was tolerated as well as interferon alfa-2b plus ribavirin and produced significant improvements in the rate of sustained viral reduction compared with interferon alfa-2b plus ribavirin or peginterferon alfa-2a alone.     

Peginterferon alfa-2a and ribavirin in patients with chronic hepatitis C who have failed prior treatment

BACKGROUND & AIMS: The most effective therapy currently available for treatment of chronic hepatitis C virus (HCV) is the combination of peginterferon and ribavirin. This study evaluated the effectiveness of this treatment in patients who were nonresponders to previous interferon-based therapy. METHODS: The first 604 patients enrolled in the Hepatitis C Antiviral Long-Term Treatment Against Cirrhosis (HALT-C) Trial were evaluated. All were HCV RNA positive, previous nonresponders to interferon, with or without ribavirin, and had bridging fibrosis or cirrhosis on liver biopsy (Ishak fibrosis stage 3-6). Patients were retreated with peginterferon alfa-2a 180 microg/wk plus ribavirin 1000-1200 mg/day. Those with no detectable HCV RNA in serum at week 20 continued treatment for a total of 48 weeks and were then followed for an additional 24 weeks. RESULTS: Thirty-five percent of patients had no detectable HCV RNA in serum at treatment week 20, and 18% achieved sustained virologic response (SVR). Factors associated with an SVR included previous treatment with interferon monotherapy, infection with genotypes 2 or 3, a lower AST:ALT ratio, and absence of cirrhosis. Reducing the dose of ribavirin from > or =80% to < or =60% of the starting dose during the first 20 weeks of treatment was associated with a decline in SVR from 21% to 11% (P < or = 0.05). In contrast, reducing the dose of peginterferon or reducing ribavirin after week 20, when HCV RNA was already undetectable, did not significantly affect SVR. CONCLUSIONS: Selected nonresponders to previous interferon-based therapy can achieve SVR following retreatment with peginterferon alfa-2a and ribavirin.     

Improved outcomes in patients with hepatitis C with difficult-to-treat characteristics: randomized study of higher doses of peginterferon alpha-2a and ribavirin

Treatment response remains suboptimal for many patients with chronic hepatitis C, particularly those with genotype 1 and high levels of viremia. The efficacy of high-dose regimens of peginterferon alfa-2a and ribavirin was compared with conventional dose regimens in patients with features predicting poor treatment responses. Eligible treatment-na?ve adults with genotype 1 infection, hepatitis C virus (HCV) RNA >800,000 IU/mL and body weight >85 kg were randomized to double-blind treatment with peginterferon alfa-2a at 180 or 270 microg/week plus ribavirin at 1200 or 1600 mg/day for 48 weeks (four regimens were evaluated). The primary endpoint was viral kinetics during the first 24 weeks of therapy. Among patients receiving peginterferon alfa-2a (270 microg/week) the magnitude of HCV RNA reduction was significantly greater than for patients randomized to the conventional dose of peginterferon alfa-2a (180 microg/week) for the pairwise comparison for ribavirin at 1600 mg/day (P = 0.036) and numerically greater for the pairwise comparison for ribavirin at 1200 mg/day (P = 0.060). Patients randomized to the highest doses of peginterferon alfa-2a (270 microg/week) and ribavirin (1600 mg/day) experienced the numerically highest rates of sustained virologic response (HCV RNA < 50 IU/mL) and the lowest relapse rate (47% and 19%, respectively). The arm with the higher doses of both drugs was less well-tolerated than the other regimens. CONCLUSION: Higher fixed doses of peginterferon alfa-2a (270 microg/week) and ribavirin (1600 mg/day) may increase sustained virologic response rates compared with lower doses of both drugs in patients with a cluster of difficult-to-treat characteristics.     

The treatment of chronic hepatitis C with peginterferon alfa-2a (40 kDa) plus ribavirin in haemodialysed patients awaiting renal transplant

BACKGROUND/AIMS: We undertook a pilot study to investigate the efficacy and safety of peginterferon alfa-2a (40 kDa) plus ribavirin in haemodialysed chronic HCV patients awaiting renal transplant. METHODS: Patients received peginterferon alfa-2a 135 microg/week plus ribavirin 200 mg/day for 24 or 48 weeks (genotype non-1 and 1, respectively). The dose of ribavirin was tailored according to plasma concentrations and to haemoglobin levels. Outcomes in treated patients were compared with those of a matched untreated control group. RESULTS: Thirty-five patients received treatment, while 35 served as untreated controls. Thirty patients completed treatment; patients were withdrawn due to transplantation (n=2), severe anaemia (n=1), dermatitis (n=1) and non-response (n=1) resulting in a drop-out rate of 14%. Overall, 34/35 treated patients were HCV RNA negative at week 4 and had undetectable RNA at the end of treatment, compared with none of the untreated controls (ETR 97% vs 0%; p<0.001). Moreover, all achieved sustained virological response after 24 weeks of treatment-free follow-up versus no control patients (SVR 97% vs 0 %; p<0.001). CONCLUSIONS: In this study, we have shown for the first time in a large cohort of patients that HCV-patients on haemodialysis can be treated successfully with peginterferon alfa-2a (40 kDa) plus ribavirin.     

Rationale and design of the REPEAT study: a phase III, randomized, clinical trial of peginterferon alfa-2a (40 kDa) plus ribavirin in non-responders to peginterferon alfa-2b (12 kDa) plus ribavirin

OBJECTIVE: The REtreatment with PEgasys in pATients not responding to prior peginterferon alfa-2b (12 kDa)/ribavirin combination therapy (REPEAT) study is a phase III, randomized, parallel group, multinational clinical trial. The main objective is to compare the efficacy and safety of 48 and 72 weeks of treatment with peginterferon alfa-2a (40 kDa) (PEGASYS) plus ribavirin (COPEGUS) in patients who did not respond to previous peginterferon alfa-2b (12 kDa) plus ribavirin therapy. STUDY DESIGN: Patients will be randomized to one of four treatment groups: two groups will receive peginterferon alfa-2a (40 kDa) at the standard dose of 180 mug once weekly for 48 or 72 weeks. The other two groups will receive a 12-week high-dose induction regimen with peginterferon alfa-2a (40 kDa) 360 mug once-weekly followed by 60 or 36 weeks of peginterferon alfa-2a (40 kDa) 180 mug once weekly. All patients will receive the standard dose of ribavirin (1000 or 1200 mg/day) throughout treatment. The primary efficacy variable is the rate of sustained virological response, defined as non-detectable hepatitis C virus (HCV) RNA (<50 IU/ml) 24 weeks after the end of treatment. Secondary variables include the percentage of patients with non-detectable HCV RNA at the end of treatment, the percentage of patients with at least a 2-log10 decrease in serum HCV RNA at weeks 12 and 24 of treatment, and the percentage of patients with non-detectable HCV RNA at treatment weeks 12, 24 and 48. Safety data will be recorded and analysed throughout the entire course of the study with the assistance of a Safety Review Board.     

PEG IFN alfa-2a vs. alfa-2b: And the winner is …?

Peginterferon alfa-2b or alfa-2a with ribavirin for treatment of hepatitis C infection. McHutchison JG, Lawitz EJ, Shiffman ML, Muir AJ, Galler GW, McCone J, Nyberg LM, Lee WM, Ghalib RH, Schiff ER, Galati JS, Bacon BR, Davis MN, Mukhopadhyay P, Koury K, Noviello S, Pedicone LD, Brass CA, Albrecht JK, Sulkowski MS; IDEAL Study Team. N Engl J Med 2009 Aug 6;361(6):580–93.BackgroundTreatment guidelines recommend the use of peginterferon alfa-2b or peginterferon alfa-2a in combination with ribavirin for chronic hepatitis C virus (HCV) infection. However, these regimens have not been adequately compared.MethodsAt 118 sites, patients who had HCV genotype 1 infection and who had not previously been treated were randomly assigned to undergo 48 weeks of treatment with one of three regimens: peginterferon alfa-2b at a standard dose of 1.5 microg per kilogram of body weight per week or a low dose of 1.0 microg per kilogram per week, plus ribavirin at a dose of 800 to 1400 mg per day, or peginterferon alfa-2a at a dose of 180 microg per week plus ribavirin at a dose of 1000 to 1200 mg per day. We compared the rate of sustained virologic response and the safety and adverse-event profiles between the peginterferon alfa-2b regimens and between the standard-dose peginterferon alfa-2b regimen and the peginterferon alfa-2a regimen.ResultsAmong 3070 patients, rates of sustained virologic response were similar among the regimens: 39.8% with standard-dose peginterferon alfa-2b, 38.0% with low-dose peginterferon alfa-2b, and 40.9% with peginterferon alfa-2a (P = 0.20 for standard-dose vs. low-dose peginterferon alfa-2b; P = 0.57 for standard-dose peginterferon alfa-2b vs. peginterferon alfa-2a). Estimated differences in response rates were 1.8% (95% confidence interval [CI, ?2.3 to 6.0) between standard-dose and low-dose peginterferon alfa-2b and ?1.1% (95% CI, ?5.3 to 3.0) between standard-dose peginterferon alfa-2b and peginterferon alfa-2a. Relapse rates were 23.5% (95% CI, 19.9 to 27.2) for standard-dose peginterferon alfa-2b, 20.0% (95% CI, 16.4 to 23.6) for low-dose peginterferon alfa-2b, and 31.5% (95% CI, 27.9 to 35.2) for peginterferon alfa-2a. The safety profile was similar among the three groups; serious adverse events were observed in 8.6% to 11.7% of patients. Among the patients with undetectable HCV RNA levels at treatment weeks 4 and 12, a sustained virologic response was achieved in 86.2% and 78.7%, respectively.ConclusionsIn patients infected with HCV genotype 1, the rates of sustained virologic response and tolerability did not differ significantly between the two available peginterferon–ribavirin regimens or between the two doses of peginterferon alfa-2b. (ClinicalTrials.gov No. NCT00081770) 2009 Massachusetts Medical Society.     

Durability of sustained response shown in paediatric patients with chronic hepatitis C who were treated with interferon alfa-2b plus ribavirin

Long-term studies in adults indicate that sustained virologic response (SVR) after combination treatment for chronic hepatitis C (CHC) predicts long-term clearance. Although peginterferon plus ribavirin is now standard care for children with CHC, long-term follow-up studies are not yet available. This study evaluated durability of virologic response over 5 years in children previously treated with interferon alfa-2b plus ribavirin (IFN/R). Ninety-seven of 147 children with CHC, who were treated with IFN/R and completed the 6-month follow-up in two previous clinical trials, participated in this long-term follow-up study. All were assessed annually for up to 5 years; patients with SVR were assessed for durability of virologic response. Children with SVR (n = 56) and those with detectable hepatitis C virus (HCV) RNA 24-week post-treatment (n = 41) were followed for a median of 284 weeks. Overall, 70% (68/97) of patients completed the 5-year follow-up. One patient with genotype 1a CHC had SVR and relapsed at year 1 of follow-up with the same genotype. Kaplan-Meier estimate for sustained response at 5 years was 98% (95% CI: 95%, 100%). Six patients with low-positive HCV RNA levels (n = 4) or missing HCV RNA at the 24-week follow-up visit (n = 2) in the initial treatment studies had virologic response during this long-term follow-up study. Linear growth rate was impaired during treatment with rapid increases in the immediate 6 months post-treatment. Mean height percentile at the end of the 5-year follow-up was slightly less than the mean pretreatment height percentile. Five patients experienced serious adverse events; none related to study drug exposure. SVR after IFN/R predicts long-term clearance of HCV in paediatric patients; growth normalized in the majority of children during the long-term follow-up. Similar long-term results could be expected after peginterferon alfa-2b plus ribavirin treatment.     

Early Virological Response in Children with Chronic Hepatitis C Treated with Pegylated Interferon and Ribavirin

Abstract Objective: Infection with hepatitis C virus (HCV) is widespread worldwide. It is estimated that this problem affects approximately 3% of global population. By introducing weekly doses of pegylated interferon (IFN) alfa in combination with ribavirin, given daily, to chronic hepatitis C (CHC) treatment one can achieve a full inhibition of HCV replication in 54–56% of adult patients. The aim of this study was to examine the relationship between prognostic factors and early virological response (EVR) after combination treatment with peginterferon alfa- 2a or alfa-2b and ribavirin in children with CHC. Methods: Twenty-three children with chronic HCV were treated with a combination of peginterferon alfa-2a or alfa-2b once a week and ribavirin twice a day. Assessment included age at the time of infection, the length of infection, HCV genotype, viral load in serum and HCV RNA level in peripheral blood mononuclear cells (PBMCs), alanine aminotransferase (ALT) activity and adherence to therapy. The efficacy endpoint was EVR defined as undetectable HCV RNA in serum or >2 log10 decrease in HCV RNA compared with baseline values. Results: An EVR was achieved in 15 out of 23 patients (65.3%) after 12 weeks of therapy. Conclusions: Lower HCV RNA viral load have positive influence on EVR. HCV RNA presence in PBMCs and lower ALT activity do not influence the achievement of EVR. Oncologic history does not bear any influence on EVR. Adherence to the therapy has an unclear influence on the achievement of EVR in children with CHC.     

Peginterferon alfa-2a and ribavirin for chronic hepatitis C genotype 1 infections in black patients: safety, tolerability and impact on sustained virologic response

HCV infections are two-times more prevalent in black Americans than in whites. We previously reported that treatment with peginterferon alfa-2a plus ribavirin produced a sustained virologic response (SVR) rate of 26% in blacks, a lower efficacy compared with the SVR in whites. Here we detail the safety profile of peginterferon alfa-2a plus ribavirin and the relationship between treatment adherence, defined by cumulative drug exposure, and SVR in 78 black patients infected with HCV genotype 1. Sixty-two (79%) patients completed 48 weeks of combination treatment. Peginterferon alfa-2a dose was modified for neutropenia in 36 patients (46%), whereas ribavirin dose was modified due to anemia in 31 patients (40%). The SVR rate was related to medication exposure, based on the percentage of the planned doses of peginterferon and ribavirin that the patients received. The SVR rates were 33, 25 and 0% in patients who received >80, 61-80 and 80, 61-80 and 80% of the total planned doses of both peginterferon and ribavirin and 7% (1 of 14) in patients who received 60% exposure to both, and 0% in patients with 60% of the planned peginterferon alfa-2a and ribavirin doses for 48 weeks was associated with a greater SVR in black patients with HCV genotype 1 infections.     

Antiviral activity of telaprevir (VX-950) and peginterferon alfa-2a in patients with hepatitis C

Telaprevir (VX-950), an inhibitor of the hepatitis C virus (HCV) NS3/4A protease, substantially decreased plasma HCV RNA levels in a prior clinical study. The present study evaluated viral kinetics and safety during dosing with telaprevir alone and in combination with peginterferon alfa-2a for 14 days. Previously untreated patients with genotype 1 hepatitis C were randomized to receive placebo and peginterferon alfa-2a (n = 4); telaprevir (n = 8); or telaprevir and peginterferon alfa-2a (n = 8). Telaprevir was given as 750 mg oral doses every 8 hours; peginterferon alfa-2a was given as weekly 180 mug subcutaneous injections. The median change in HCV RNA from baseline to day 15 was -1.09 log(10) (range, -2.08 to -0.46) in the placebo and peginterferon alfa-2a group; -3.99 log(10) (range, -5.28 to -1.26) in the telaprevir group, and -5.49 log(10) (range, -6.54 to -4.30) in the telaprevir and peginterferon alfa-2a group. Day 15 HCV RNA levels were undetectable in 4 patients who received telaprevir and peginterferon alfa-2a and in 1 patient who received telaprevir alone. No viral breakthrough occurred in patients who received telaprevir and peginterferon alfa-2a. The majority of adverse events were mild. There were no serious adverse events or premature discontinuations. Twelve weeks after starting off-study standard therapy, HCV RNA was undetectable in all 8 patients in the telaprevir and peginterferon alfa-2a group, 5 patients in the telaprevir group, and 1 patient in the placebo and peginterferon alfa-2a group. CONCLUSION: This study confirmed the substantial antiviral effects of telaprevir and showed an increased antiviral effect of telaprevir combined with peginterferon alfa-2a.     

Peginterferon alfa-2b plus weight-based ribavirin for 24 weeks in patients with chronic hepatitis C virus genotype 1 with low viral load who achieve rapid viral response

In chronic hepatitis C (CHC), treatment duration may be individualized according to time to first undetectable hepatitis C virus (HCV) RNA, with patients who attain undetectable HCV RNA early in treatment being candidates for shorter regimens. The aim of this study was to determine the relapse rate in patients with CHC genotype (G) 1 infection and low baseline viral load who achieved undetectable HCV RNA by week 4 [rapid virologic response (RVR)] when treated for 24 weeks. This was an open-label, multicentre, noninterventional study. Adult patients with G1 CHC infection and baseline viral load <600,000 IU/mL who attained RVR were treated with peginterferon alfa-2b (1.5 μg/kg/week) plus ribavirin (800-1200 mg/day) for 24 weeks, then followed for a further 24 weeks. The primary endpoint was relapse rate, defined as the proportion of patients with undetectable HCV RNA at treatment week 24 and detectable HCV RNA at week 24 follow-up. The secondary efficacy endpoint was sustained virologic response (SVR). Overall, 170 patients were included in the efficacy-evaluable population. The relapse rate was 9.7% (16/165, 95% confidence interval: 0.06-0.15), and SVR was attained by 149 of 170 patients (87.6%). Virologic outcomes were consistent regardless of age, gender, body weight and genotype. Seven patients reported treatment-emergent serious adverse events (AEs), and four patients discontinued treatment because of an AE. This study further demonstrates that peginterferon alfa-2b plus weight-based ribavirin for 24 weeks is an effective treatment strategy for treatment-naive patients with G1 CHC and low viral load who attain RVR.     

Antiviral effects and safety of telaprevir, peginterferon alfa-2a, and ribavirin for 28 days in hepatitis C patients

BACKGROUND/AIMS: This study assessed the safety and antiviral effects of telaprevir (VX-950) in combination with peginterferon alfa-2a and ribavirin. METHODS: Twelve treatment-nai ve patients with chronic genotype 1 hepatitis C virus infection received telaprevir (750mg q8h), peginterferon alfa-2a (180mug/week), and ribavirin (1000 or 1200mg/day) for 28 days. Patients could then start off-study treatment with peginterferon alfa-2a and ribavirin for up to 44 weeks, at the discretion of the investigator and patient. RESULTS: The combination of telaprevir, peginterferon alfa-2a, and ribavirin was well tolerated, with no serious adverse events or treatment discontinuations. Rash or pruritus occurred in 5 of the 12 patients; all cases resolved either during or after the end of telaprevir treatment. All 12 patients had undetectable HCV RNA levels by day 28 (rapid viral response, RVR). Eight patients completed 44 weeks of off-study peginterferon alfa-2a and ribavirin treatment. Eight patients achieved a sustained viral response (SVR), including one patient who received only 22 weeks of treatment. CONCLUSIONS: The combination of telaprevir, peginterferon alfa-2a, and ribavirin was generally well tolerated. Events of pruritus and rash resolved during or after end of telaprevir dosing. All 12 patients achieved an RVR.     

Peginterferon alfa-2a (40KD) plus ribavirin in chronic hepatitis C patients who failed previous interferon therapy

BACKGROUND: The management of patients with chronic hepatitis C who have relapsed or failed to respond to interferon based therapies is an important issue facing hepatologists. AIMS: We evaluated the efficacy and safety of peginterferon alfa-2a (40KD) plus ribavirin in this population by conducting a multicentre open label study. PATIENTS: Data from adults with detectable serum hepatitis C virus (HCV) RNA who had not responded or had relapsed after previous conventional interferon or conventional interferon/ribavirin combination therapy were analysed. METHODS: Patients were retreated with peginterferon alfa-2a (40KD) 180 microg/week plus ribavirin 800 mg/day for 24 or 48 weeks at the investigators' discretion. The study was conceived before the optimal dose of ribavirin (1000/1200 mg/day) for patients with genotype 1 was known. The primary endpoint was sustained virological response (SVR), defined as undetectable HCV RNA (<50 IU/ml) after 24 weeks of follow up. The analysis was conducted by intention to treat. RESULTS: A total of 312 patients (212 non-responders, 100 relapsers) were included. Of these, 28 patients were treated for 24 weeks and 284 for 48 weeks. Baseline characteristics between non-responders and relapsers were similar although more non-responders had genotype 1 infection (87% v 69%). Overall SVR rates were 23% (48/212) for non-responders and 41% (41/100) for relapsers. When data were analysed by genotype, SVR rates were 24% (61/253) in genotype 1 and 47% (28/59) in genotype 2/3. CONCLUSIONS: These results in a large patient cohort demonstrate that it is possible to cure a proportion of previous non-responders and relapsers by retreating with peginterferon alfa-2a (40KD) plus ribavirin.     

Predicting sustained virological responses in chronic hepatitis C patients treated with peginterferon alfa-2a (40 KD)/ribavirin

BACKGROUND/AIMS: Prediction of sustained virological response (SVR) during treatment would allow clinicians to identify patients most likely to benefit from therapy. METHODS: Retrospective analysis of data from 1121 adults with chronic hepatitis C treated for 48 weeks with peginterferon alfa-2a (40 KD) 180 microg/week plus placebo or ribavirin (1000/1200 mg/day), or interferon alfa-2b 3 MIU three times/week plus ribavirin in a randomized, multinational, study. RESULTS: 67% of patients treated with peginterferon alfa-2a (40 KD)/ribavirin with early virological responses (HCV RNA negative or > or = 2 log10 decrease) at week 12 had SVRs at week 72 (HCV RNA < 50 IU/mL). The negative predictive value (NPV) was 97%. The probability of an SVR increased with the rapidity of HCV RNA suppression. The highest SVR rates were achieved in patients with rapid virological responses at week 4, but the corresponding NPV (74%) is too low for a decision criterion. In patients with early virological responses by week 12, the SVR rate was approximately 20% lower in those who received <80% compared with patients who received > or = 80% of the planned ribavirin dose. CONCLUSIONS: Early, sustained suppression of HCV replication portends an SVR. Cessation of treatment may be contemplated in patients without a > or = 2 log10 reduction in HCV RNA after 12 weeks.     

Pegylated interferon alfa-2b plus ribavirin for the treatment of chronic hepatitis C genotype 4 in adolescents

Background. Hepatitis C is endemic in the Middle East where genotype R accounts for most cases. Data regarding the safety and efficacy of peginterferon plus ribavirin for the treatment of chronic hepatitis C in children and adolescents, particularly those infected with genotype R is limited.Aim. To evaluate the efficacy and tolerability of peginterferon alfa-2b in combination with ribavirin in adolescents chronically infected with HCV genotype R.Patients and methods. In an open-labeled, uncontrolled pilot study, 12 adolescents (rangeIR-17 years) were treated with subcutaneous peginterferon alfa-2b at a dose of 1.5 mg/ kg body weight once per week plus oral ribavirin (15 mg/kg/day) for R8 weeks. Patients were followed for 2R weeks post-treatment. All patients had biopsy proven hepatitis without cirrhosis.Results. One patient withdrew from the study due to developing insulin dependent diabetes mellitus R months into treatment. The remaining patients received at least 80% of the prescribed dose of pegylated interferon and ribavirin. Sustained viral response was observed in 9 patients (75%). The most frequent side effect was flu like illness which was reported in all patients. Sixty seven percent had leucopenia, but only one individual required adjuvant therapy with hematologic growth factor. Four patients had anemia requiring ribavirin dose reduction. One patient developed hypothyroidism.Conclusion. Combination treatment of peginterferon alfa-2b with ribavirin appears to be efficacious and relatively safe in adolescents with chronic hepatitis C genotype R.B.     

Characterization of nonrapid virologic response patients infected with HCV genotype 1 who may relapse after standard therapy with peginterferon plus ribavirin

Approximately 50% of patients with hepatitis C virus (HCV) genotype 1 treated with peginterferon alfa-2a/ribavirin discontinue treatment early or experience a suboptimal response despite 48 weeks of therapy. The objective of this analysis was to develop a model to identify nonrapid virologic response (non-RVR) patients who may be candidates for intensified therapy that would increase treatment response. The retrospective analysis included non-RVR patients from four trials of 48-week peginterferon alfa-2a/ribavirin treatment. Patients were grouped into those who cleared virus between weeks 5 and 12 (complete early virologic responders, cEVR) or between weeks 13 and 24 (slow responders). A model was developed to predict relapse at the end of follow-up (week 72). An optimal model was evaluated and compared with current practice by using receiver operating characteristic curves, sensitivity and specificity. In total, 539 non-RVR patients were eligible for analysis of which 72% experienced cEVR and 28% were slow responders. Variables associated with relapse included age, ethnicity, baseline HCV RNA and interval of time to HCV RNA undetectable. The optimal model was most accurate at predicting patients at risk for relapse. The practice of considering treatment intensification (e.g. extending treatment duration) in all slow responders was less accurate but likely most practical. A week 4 HCV <2-log reduction was the earliest but least accurate marker. We developed a model that could identify non-RVR patients at high risk for relapse after 48 weeks of peginterferon alfa-2a plus ribavirin and who may benefit from intensified therapy to reduce this risk of relapse.