Response to peginterferon alfa-2a (40KD) in HBeAg-negative CHB: on-treatment kinetics of HBsAg serum levels vary by HBV genotype.

BACKGROUND & AIMS: We investigated whether HBV genotype influences on-treatment HBsAg kinetics and/or the end-of-treatment HBsAg levels associated with long-term virological response in HBeAg-negative chronic hepatitis B patients treated with peginterferon alfa-2a±lamivudine in the Phase III trial. METHODS: All patients (n=230) who participated in long-term follow-up were included according to the availability of HBsAg level measurements. Long-term virological response was defined as HBV DNA ≤ 10,000cp/ml (1786IU/ml) at 5 years post-treatment. Genotype-specific end-of-treatment HBsAg levels associated with long-term virological response (identified by ROC analysis) were assessed in 199 patients with HBsAg measurements available at baseline and end-of-treatment. HBsAg kinetics according to genotype and long-term virological response were investigated in the 117 patients with additional samples available at weeks 12, 24, and 72. RESULTS: Baseline HBsAg levels were significantly higher for A than B, C, and D genotypes (p<0.05). On-treatment HBsAg kinetics varied according to HBV genotype. The difference between responders and non-responders was greatest for genotype A from weeks 12-24; for genotypes B and D from baseline to week 12; there was no significant difference over any timeframe for genotype C. High positive predictive values for long-term virological response could be obtained by applying end-of-treatment genotype-specific cut-offs: 75%, 47%, 71%, and 75% for genotypes A (<400IU/ml), B (<50IU/ml), C (<75IU/ml), and D (<1000IU/ml), respectively. CONCLUSIONS: On-treatment HBsAg kinetics vary between HBV genotypes. Genotype-specific monitoring timeframes and end-of-treatment thresholds could ameliorate response-guided treatment of HBeAg-negative chronic hepatitis B.

Safety of peginterferon alfa-2a plus ribavirin in a large multinational cohort of chronic hepatitis C patients.

BACKGROUND & AIMS: Peginterferon plus ribavirin has been the standard of care for chronic hepatitis C for a decade and an essential component of combination regimens for this disease. This large multinational open-label study aimed to better define the incidence of serious adverse events (SAEs) and non-serious adverse events of special interest in patients receiving peginterferon alfa-2a/ribavirin. METHODS: Patients were assigned at the investigator's discretion to 24- or 48-week treatment with peginterferon alfa-2a 180 µg/week and ribavirin 800 mg/day or 1000/1200 mg/day. All AEs, defined as SAEs and non-SAEs of special interest, were recorded during treatment and for 12 weeks thereafter. Non-SAEs of special interest included those leading to dose reduction/discontinuation, neutropenia, thrombocytopenia, anaemia, ALT elevations leading to dose modification and unknown/unexpected AEs. RESULTS: Of 1675 and 7178 patients assigned to 24 and 48 weeks of treatment, respectively, 87.6 and 68.3% completed therapy, whereas 6.4 and 10.3% prematurely stopped peginterferon alfa-2a treatment because of AEs. Among patients assigned to 24 and 48 weeks, 37.4 and 46.9%, respectively, reported any AE (SAE or non-SAE of special interest); 4.2 and 6.6% reported SAEs and 35.2 and 44.0% reported non-SAEs of special interest. Female gender, increasing age and cirrhosis were significantly associated with dose reductions of either drug. Increasing age (and female gender in the case of ribavirin) was significantly associated with treatment discontinuation. CONCLUSION: This study confirmed the safety and tolerability profile of peginterferon alfa-2a/ribavirin and identified patient subgroups at higher risk of dose reductions and discontinuations, thus allowing optimum management of AEs.

Rapid virological response is the most important predictor of sustained virological response across genotypes in patients with chronic hepatitis C virus infection.

BACKGROUND & AIMS: The probability of response to peginterferon and ribavirin is associated with numerous host and virological factors. Attainment of a rapid virological response (RVR), defined as undetectable HCV RNA at week 4 during treatment with peginterferon and ribavirin, is highly predictive of sustained virological response (SVR). The aim of the present study was to determine the relative importance of the kinetics of antiviral response compared to baseline host and virological factors for predicting SVR. METHODS: A retrospective analysis of 1383 patients, encompassing genotypes 1-4, treated with peginterferon alfa-2a and ribavirin, was performed. Baseline characteristics were compared across HCV genotypes and pretreatment factors associated with RVR were identified. The relative significance of RVR compared to other baseline factors for predicting SVR was analyzed by multiple logistic regression analysis. RESULTS: RVR was achieved by 16% of patients with genotype 1 and 71% and 60% of those with genotype 2 and 3, respectively. Among patients who achieved RVR, the rate of SVR was high across all genotypes and ranged from 88% to 100% (genotypes 1-4). Baseline factors predictive of RVR included genotype, younger age, lower initial viral load, higher ALT ratio, absence of advanced fibrosis, and younger age. Notably, the presence of RVR generated the highest odds ratio (5.47, 95% confidence interval 3.97-7.52) for predicting SVR in multiple logistic regression analysis of these factors. CONCLUSIONS: Attainment of RVR varies by genotype and is associated with several baseline factors. Patients who achieve RVR have the highest rates of SVR, regardless of genotype. These findings have important implications for predicting and managing response-guided combination antiviral therapies.

Efficacy and safety of peginterferon alfa-2a (40KD) plus ribavirin in hepatitis C patients with advanced fibrosis and cirrhosis.

UNLABELLED: The objective of this study is to determine the efficacy and safety of peginterferon alfa-2a (40 KD)/ribavirin in patients with advanced fibrosis. Data from 341 genotype 1/4 patients (99 with bridging fibrosis/cirrhosis) treated for 48 weeks and 1547 genotype 2/3 patients (380 with bridging fibrosis/cirrhosis) treated for 16 or 24 weeks enrolled in three randomized international studies were analyzed. Sustained virological response (SVR) rates decreased progressively from 60% in genotype 1/4 patients without advanced fibrosis to 51% in those with bridging fibrosis and 33% in those with cirrhosis (trend test P = 0.0028); and from 76% to 61% and 57%, respectively, in genotype 2/3 patients treated for 24 weeks (trend test P < 0.0001). Irrespective of genotype, patients without advanced fibrosis were more likely to have an earlier response to treatment that was associated with higher SVR rates and lower relapse rates during untreated follow-up. Among patients with or without a diagnosis of advanced fibrosis, rates of SVR and relapse were similar for patients with similar responses in the first 12 weeks. CONCLUSION: Compared with patients with less severe disease, SVR rates are significantly lower in patients with advanced fibrosis. However, irrespective of genotype and degree of fibrosis, the time to become hepatitis C virus (HCV) RNA undetectable was the strongest predictor of SVR.

Milestones and perspectives in viral hepatitis B.

There have been numerous research milestones since the discovery of the hepatitis B virus (HBV) in the 1960s. These mark major advances in the serology and epidemiology of HBV infection, in identifying the wide clinical spectrum of acute and chronic hepatic diseases as well as the extrahepatic conditions induced by this virus, the molecular biology of the virus including its variants and mutants, its molecular diagnosis and monitoring, the host immune responses to the infecting virus, the pathogenesis and immunopathogenesis of liver disease as well as its natural course and outcome. These landmark discoveries are the firm background for current and future developments in treatment. There are three consecutive and partly overlapping chronological periods to treatment milestones beginning with recombinant standard interferon-alpha (IFN-α) in the 1980s, then oral antivirals from 1998 to the present and in 2005 pegylated IFN-α (PEG-IFN). The renewed interest in PEG-IFN-α treatment is now focused on both HBeAg-positive and HBeAg-negative chronic hepatitis B and it now also aims at HBsAg loss when associated with on-treatment monitoring of serum HBV DNA and HBsAg levels, resulting in the closest thing to a cure of hepatitis B. The impressive progress made in all aspects of hepatitis B research suggests that curative therapy may be developed for all patients and for all phases of HBV infection in the foreseeable future. However for the moment, realistic efforts should be made to make treatment as widely available and affordable as possible and to apply current therapies to significantly reduce HBV morbidity and mortality.

Definition of rapid virologic response with a highly sensitive real-time PCR-based HCV RNA assay in peginterferon alfa-2a plus ribavirin response-guided therapy.

BACKGROUND & AIMS: Assessing hepatitis C virus (HCV)-RNA levels is integral to response-guided therapy. Rules for early discontinuation and determination of treatment duration were mainly established with HCV-RNA assays with a detection limit of 50IU/ml (COBAS Amplicor HCV [CA]). The currently used real-time PCR-based COBAS Ampliprep/COBAS-TaqMan HCV (CAP-CTM) test has a detection limit of approximately 10IU/ml. It is unknown whether shortening of treatment duration to 16/24 weeks in patients with rapid virological response at week 4 (RVR) and viral loads between 10 and 50IU/ml is possible. METHODS: We reanalysed stored serum from two large, multinational, randomized trials in which patients were treated with peginterferon alfa-2a/ribavirin (n=962). Results of CAP-CTM with truly undetectable HCV RNA and those <15IU/ml, which includes patients with residual viraemia (<15), were compared with the originally obtained results using the CA assay. RESULTS: RVR rates were comparable for CA (<50) and CAP-CTM (<15) with 32% and 32% for genotype (gt) 1 and 50% and 49% for gt2/3 patients, respectively. A significantly smaller number of samples really had truly undetectable HCV RNA by the CAP-CTM assay (24% for gt1, 37% for gt2/3). However, sustained virological response rates after shortened treatment (16/24weeks) were not significantly different in patients with a RVR <50, a RVR <15 and RVR undetectable (82%, 83%, 83% for 24weeks gt1 and 95%, 95%, 94% for 16weeks gt2/3). CONCLUSIONS: Shortening the treatment duration to 16/24weeks can be performed on the basis of a RVR with HCV-RNA concentrations <15IU/ml by the CAP-CTM assay.

Early predictors of anemia in patients with hepatitis C genotype 1 treated with peginterferon alfa-2a (40KD) plus ribavirin.

OBJECTIVE: Adherence to ribavirin is one factor that is critically important in the treatment of hepatitis C virus infection. However, ribavirin can be associated with clinically significant hemolytic anemia resulting in dose modifications in up to one-quarter of patients. Currently, baseline predictors of considerable anemia are not sufficiently discriminating for routine therapeutic intervention. The objective of this analysis was to elucidate baseline and on-treatment factors predictive of a considerable hemoglobin drop at week 4. METHODS: Multivariate logistic regression analysis was used to explore possible predictors for considerable hemoglobin decline (> or =2.5 g/dL) at week 4 among patients receiving peginterferon alfa-2a (40KD) and ribavirin (1,000/1,200 mg/day). RESULTS: A total of 555 patients were included in this analysis. At week 4, 236 patients exhibited a > or =2.5 g/dL decrease in hemoglobin. By regression analysis the most important independent variables associated with a decrease in hemoglobin of > or =2.5 g/dL were baseline creatinine clearance (P= 0.0003) and a rapid decline in hemoglobin of > or =1.5 g/dL at week 2 (P < 0.0001). Considerable hemoglobin decreases at week 4 were also significantly associated with early ribavirin dose reductions and a lower cumulative daily dose of ribavirin. CONCLUSION: Patients with impaired renal function may be at an increased risk of ribavirin-related anemia and should be monitored accordingly. Furthermore, a hemoglobin drop of > or =1.5 g/dL by week 2 was an excellent early predictor for subsequent considerable hemoglobin decreases and might be used to identify candidates for early intervention against anemia in order to help maintain ribavirin dosing and avoid suboptimal exposure.

Predicting efficacy and safety outcomes in patients with hepatitis C virus genotype 1 and persistently 'normal' alanine aminotransferase levels treated with peginterferon alpha-2a (40KD) plus ribavirin.

BACKGROUND: Currently, the approved dosage of ribavirin has not been studied in patients with 'normal' alanine aminotransferase (ALT) levels. METHODS: Modelling and simulations were performed using generalised additive models (GAMs) to predict the incidence of anaemia and rate of sustained virological response (SVR) in patients with hepatitis C virus (HCV) genotype 1 and persistently 'normal' ALT levels treated with peginterferon alpha-2a (40KD) 180 microg/week plus ribavirin 1000/1200 mg/day for 48 weeks. RESULTS: Model-based simulations predicted that SVR rates would increase from 39 to 48% if patients with genotype 1 and persistently 'normal' ALT levels had received the standard weight-adjusted dose of ribavirin. This was similar to the predicted 49% SVR rate for genotype 1 patients with elevated ALT levels. The incidence of anaemia was predicted to increase from 13% to 23% in patients with persistently 'normal' ALT activity and was higher than that predicted for patients with elevated ALT levels; however, the difference appeared to be largely explained by the higher proportion of women in the former group. CONCLUSIONS: Simulations based on GAM suggest that regimens for patients with HCV genotype 1 should include the standard weight-adjusted dose of ribavirin, as similar SVR rates are predicted to be achieved, regardless of patients' ALT status at baseline.

Peginterferon-alpha2a and ribavirin combination therapy in chronic hepatitis C: a randomized study of treatment duration and ribavirin dose.

BACKGROUND: Treatment with pegylated interferon (peginterferon) and ribavirin for 48 weeks is more effective than conventional interferon and ribavirin in patients with chronic hepatitis C. OBJECTIVE: To assess the efficacy and safety of 24 or 48 weeks of treatment with peginterferon-alpha2a plus a low or standard dose of ribavirin. DESIGN: Randomized, double-blind trial. SETTING: 99 international centers. PATIENTS: 1311 patients with chronic hepatitis C. INTERVENTION: Peginterferon-alpha2a, 180 microg/wk, for 24 or 48 weeks plus a low-dose (800 mg/d) or standard weight-based dose (1000 or 1200 mg/d) of ribavirin. MEASUREMENT: Sustained virologic response: undetectable HCV RNA concentration at the end of treatment and during 12 to 24 weeks of follow-up. RESULTS: Overall and in patients infected with HCV genotype 1, 48 weeks of treatment was statistically superior to 24 weeks and standard-dose ribavirin was statistically superior to low-dose ribavirin. In patients with HCV genotype 1, absolute differences in sustained virologic response rates between 48 and 24 weeks of treatment were 11.2% (95% CI, 3.6% to 18.9%) and 11.9% (CI, 4.7% to 18.9%), respectively, between standard- and low-dose ribavirin. Sustained virologic response rates for peginterferon-alpha2a and standard-dose ribavirin for 48 weeks were 63% (CI, 59% to 68%) overall and 52% (CI, 46% to 58%) in patients with HCV genotype 1. In patients with HCV genotypes 2 or 3, the sustained virologic response rates in the 4 treatment groups were not statistically significantly different. CONCLUSION: Treatment with peginterferon-alpha2a and ribavirin may be individualized by genotype. Patients with HCV genotype 1 require treatment for 48 weeks and a standard dose of ribavirin; those with HCV genotypes 2 or 3 seem to be adequately treated with a low dose of ribavirin for 24 weeks.

Peginterferon-alpha2a (40 kDa) for chronic hepatitis C.

Pegylated IFN-alpha(2a) (PEG-IFN-alpha(2a) [40 kDa]; Pegasys, Hoffmann-La Roche) is a new subcutaneous formulation of IFN-alpha(2a), produced by its attachment to a 40 kDa branched polyethylene glycol moiety by a stable amide bond. PEG-IFN-alpha(2a) 180 micro g once-weekly has enhanced pharmacokinetic and pharmacodynamic properties which translate into significantly improved efficacy and similar safety and tolerability compared with IFN-alpha in patients with chronic hepatitis C even with underlying cirrhosis. The combination of PEG-IFN-alpha(2a) (40 kDa) plus ribavirin produces significantly better sustained virological responses than the combination of IFN-alpha(2b) and ribavirin, while it is accompanied by a similar or even lower incidence of adverse events and better quality of life. PEG-IFN-alpha(2a) (40 kDa) is the first pegylated IFN-alpha for which evidence-based recommendations can be made on optimum therapy duration and ribavirin dose according to HCV genotype. PEG-IFN-alpha(2a) (40 kDa) is expected to improve the efficacy and tolerability of treatment for chronic hepatitis C.

Prediction of sustained virological response in chronic hepatitis C patients treated with peginterferon alfa-2a (40KD) and ribavirin.

OBJECTIVE: Patient- and virus-related factors influence the response of patients with chronic hepatitis C to interferon-based therapy. The purpose of this study was to model the probability of achieving a sustained virological response in individual patients, taking into consideration various predictive factors. MATERIAL AND METHODS: We combined data from two randomized, multinational trials in which patients received peginterferon alfa-2a (40KD) plus ribavirin. The logistic regression model for patients infected with hepatitis C virus genotype 1 included age, viral load, histology, alanine aminotransferase quotient, body mass index, treatment duration, ribavirin dose and adherence. RESULTS: In the genotype 1 model, varying baseline factors had a striking effect on the probability of sustained virological response. A dramatic difference in the probability of sustained virological response was seen in a series of hypothetical patients in whom five factors were varied to represent best and worst case scenarios. The best case scenario (age 20 years; no cirrhosis/bridging fibrosis; alanine aminotransferase quotient=7; body mass index 20 kg/m2; viral load 40,000 IU/mL) was associated with a 97% probability of sustained virological response, compared with 7% in the worst case scenario (age 60 years; cirrhosis/bridging fibrosis; alanine aminotransferase quotient=1; body mass index 30 kg/m2; viral load 9,000,000 IU/mL). Both adherence to treatment and achieving an early virological response increased the probability of sustained virological response. CONCLUSIONS: In treatment-naïve patients with chronic hepatitis C, host factors play a major role in determining treatment outcome and the logistic regression model is useful for predicting the probability of sustained virological response in individual patients.

New developments in the treatment of chronic hepatitis B.

Significant progress has been made during the last 2 years in the treatment of chronic hepatitis B (CHB). Treatment decisions differ significantly depending on whether patients are HBeAg+ or HBeAg-, treatment-naive or nucleoside/nucleotide-resistant, and in early or advanced stages of liver disease. Courses of finite duration, aiming to achieve sustained off-therapy responses, are practically restricted to HBeAg+ patients with compensated chronic liver disease, whereas long-term therapy aiming to achieve maintained on-therapy remission is mostly applicable to HBeAg- individuals either with early or advanced liver disease. A course of finite duration with pegylated (PEG)-IFN-alpha-2a offers the highest probability of sustained off-therapy response in HBeAg+ individuals, as well as in some HBeAg- individuals. Long-term therapy with nucleoside/nucleotide analogues, both in HBeAg+ and HBeAg- CHB, has most favourable effects on patient outcome, provided that virological and biochemical remission is maintained without development of viral resistance. The best results are achievable with potent analogues suppressing serum hepatitis B virus (HBV) DNA to non-detectability by most sensitive techniques. The best 2-year resistance profile has hitherto been reported with entecavir monotherapy, and the best long-term resistance profile was seen with adefovir of 5-year duration. Adefovir is effective in most lamivudine (LAM)-resistant patients, but should be administered as an add-on rather than as a substitute for LAM. Combination therapies have entered the treatment arena of CHB by the side doors of LAM-resistance and of end-stage liver disease, and the most recent results suggest that treatment with combinations of two strong nucleosides/nucleotides with different resistance profiles may turn out to be the optimal first-line/first choice option in CHB.

Early identification of HCV genotype 1 patients responding to 24 weeks peginterferon alpha-2a (40 kd)/ribavirin therapy.

Approximately one third of hepatitis C virus (HCV) genotype 1 patients achieved a sustained virological response (SVR) after 24 weeks of treatment with peginterferon alpha-2a (40 kd) plus ribavirin in a randomized, multinational trial. We aimed to identify factors associated with a rapid virological response (RVR) at week 4 (HCV RNA <50 IU/mL) and a SVR (HCV RNA <50 IU/mL at the end of follow-up) in these patients. Stepwise multiple logistic regression analysis was used to explore the prognostic factors for a RVR and SVR in genotype 1 patients treated for 24 weeks. Fifty-one of 216 (24%) genotype 1 patients in the 24-week treatment groups had a RVR. SVR rates were considerably higher in patients with than without [corrected] a RVR (89% vs. 19%, respectively). Patients with a baseline HCV RNA of less than 200,000 IU/mL (OR 9.7, 95% CI 4.2-22.5; P < .0001) or 200,000-600,000 IU/mL (OR 5.6, 95% CI 1.5-9.1; P = .0057) were more likely to achieve a RVR than those with HCV RNA greater than 600,000 IU/mL. HCV subtype (1b vs. 1a) was also independently associated with RVR (OR 1.8, 95% CI 0.9-3.7; P = .0954). RVR (OR 23.7 vs. no RVR, 95% CI 9.1-61.7) and baseline HCV RNA less than 200,000 IU/mL (OR 2.7 vs. > 600,000 IU/mL, 95% CI 1.1-6.3; P < .026) were significant and independent predictors of SVR in patients treated for 24 weeks. In conclusion, patients infected with HCV genotype 1 and treated with peginterferon alpha-2a/ribavirin sustained a RVR 24% of the time. This portends an 89% probability of a SVR after 24 weeks of treatment.

Chronic hepatitis B: a critical appraisal of current approaches to therapy.

BACKGROUND & AIMS: Treatment of chronic hepatitis B (CHB) involves a number of complex and controversial issues. Expert opinions may differ from those of practicing hepatologists and gastroenterologists. We aimed to explore this issue further after a critical review of the literature. METHODS: A panel of 14 international experts graded the strength of evidence for 16 statements addressing 3 content areas: patient selection, therapeutic end points, and treatment options. Available data relating to the statements were reviewed critically in 3 small work groups. After discussion of each statement with the entire panel, the experts voted anonymously to accept or reject statements based on the strength of evidence and their experience. A total of 241 members of the American Association for the Study of Liver Diseases (AASLD) responded to the same statements and their responses were compared with those of the experts. A discordant response was defined as a difference of more than 20% in any of the 5 graded levels of response (accept or reject) between the 2 groups. RESULTS: With the exception of 2 statements, the experts' responses were relatively uniform. However, the responses of the AASLD members were discordant from the experts in 12 statements, spanning all 3 content areas. CONCLUSIONS: Several areas of disagreement on the management of CHB exist between experts and AASLD members. Our results indicate a potential knowledge gap among practicing hepatologists. Better educational efforts are needed to meet the challenge of managing this complex disorder in which even expert opinion occasionally may disagree.

Treatment of chronic hepatitis C infection with peginterferons plus ribavirin.

Interferon monotherapy provided the first hope for patients with chronic hepatitis C that the virus could be permanently eradicated. An important development in treating this disease was the recognition that the effects of interferon could be greatly enhanced by combining it with ribavirin, a nucleoside analogue. This combination regimen essentially doubled the sustained virological response rates seen with interferon alone. Recently, modified forms of interferon have been developed that-when used in combination with ribavirin-demonstrate even better efficacy. Thus, peginterferon alfa-2a (Hoffman La-Roche, Nutley, NJ) and peginterferon alfa-2b (Schering-Plough, Kenilworth, NJ) are the latest innovations for the treatment of chronic hepatitis C. The addition of a polyethylene glycol molecule to the native interferon protein favorably alters the pharmacokinetic profile, allowing for once-weekly administration, and leads to superior efficacy compared to standard interferon preparations. This article reviews the data from clinical trials of peginterferon alfa-2a and peginterferon alfa-2b.