Peginterferon alfa-2b and ribavirin for the treatment of chronic hepatitis C in blacks and non-Hispanic whites

Hepatitis C in African Americans

The care of hepatitis C virus (HCV) in African Americans represents an opportunity to address a major health disparity in medicine. In all facets of HCV infection, African Americans are inexplicably affected, including in the prevalence of the virus, which is higher among them compared with most of the racial and ethnic groups. Ironically, although fibrosis rates may be slow, hepatocellular carcinoma and mortality rates appear to be higher among African Americans. Sustained viral response (SVR) rates have historically significantly trailed behind Caucasians. The reasons for this gap in SVR are related to both viral and host factors. Moreover, low enrollment rates in clinical trials hamper the study of the efficacy of anti-viral therapy. Nevertheless, the gap in SVR between African Americans and Caucasians may be narrowing with the use of direct-acting agents. Gastroenterologists, hepatologists, primary care physicians, and other health-care providers need to address modifiable risk factors that affect the natural history, as well as treatment outcomes, for HCV among African Americans. Efforts need to be made to improve awareness among health-care providers to address the differences in screening and referral patterns for African Americans.

An interferon response gene signature is associated with the therapeutic response of hepatitis C patients

Infection with the hepatitis C virus (HCV) is a major cause of chronic liver diseases and hepatocellular carcinoma worldwide, and thus represents a significant public health problem. The type I interferon (IFN), IFNα, has been successful in treating HCV-infected patients, but current IFN-based treatment regimens for HCV have suboptimal efficacy, and relatively little is known about why IFN therapy eliminates the virus in some patients but not in others. Therefore, it is critical to understand the basic mechanisms that underlie the therapeutic resistance to IFN action in HCV-infected individuals, and there is an urgent need to identify those patients most likely to respond to IFN therapy for HCV. To characterize the response of HCV-infected patients to treatment with IFNα, the expression of an IFN-response gene signature comprised of IFN-stimulated genes and genes that play an important role in the innate immune response was examined in liver biopsies from HCV-infected patients enrolled in a clinical trial. In the present study we found that the expression of a subset of IFN-response genes was dysregulated in liver biopsy samples from nonresponsive hepatitis C patients as compared with virologic responders. Based on these findings, a statistical model was developed to help predict the response of patients to IFN therapy, and compared to results obtained to the IL28 mutation model, which is highly predictive of the response to IFN-based therapy in HCV-infected patients. We found that a model incorporating gene expression data can improve predictions of IFN responsiveness compared to IL28 mutation status alone.

Antiretroviral therapy, interferon sensitivity, and virologic setpoint in human immunodeficiency virus/hepatitis C virus coinfected patients

Human immunodeficiency virus (HIV) and hepatitis C virus (HCV) cause substantial mortality, especially in persons chronically infected with both viruses. HIV infection raises plasma HCV RNA levels and diminishes the response to exogenous alpha interferon (IFN). The degree to which antiretroviral therapy (ART) control of infection overcomes these HIV effects is unknown. Participants with HIV-HCV coinfection were enrolled in a trial to measure HCV viral kinetics after IFN administration (ΔHCVIFN ) twice: initially before (pre-ART) and then after (post-ART) HIV RNA suppression. Liver tissue was obtained 2-4 hours before each IFN injection to measure interferon stimulated genes (ISGs). Following ART, the ΔHCVIFN at 72 hours (ΔHCVIFN,72 ) increased in 15/19 (78.9%) participants by a median (interquartile range [IQR]) of 0.11 log10 IU/mL (0.00-0.40; P < 0.05). Increases in ΔHCVIFN,72 post-ART were associated with decreased hepatic expression of several ISGs (r = -0.68; P = 0.001); a 2-fold reduction in a four-gene ISG signature predicted an increase in ΔHCVIFN,72 of 0.78 log10 IU/mL (95% confidence interval [CI] 0.36,1.20). Pre- and post-ART ΔHCVIFN,72 were closely associated (r = 0.87; P < 0.001). HCV virologic setpoint also changed after ART (ΔHCVART ): transient median increases of 0.28 log10 IU/mL were followed by eventual median decreases from baseline of 0.21 log10 IU/mL (P = 0.002). A bivariate model of HIV RNA control (P < 0.05) and increased expression of a nine-gene ISG signature (P < 0.001) predicted the eventual decreased ΔHCVART .

CONCLUSION

ART is associated with lower post-IFN HCV RNA levels and that change is linked to reduced hepatic ISG expression. These data support recommendations to provide ART prior to IFN-based treatment of HCV and may provide insights into the pathogenesis of HIV-HCV coinfection.

Interferon lambda 3 rs12979860 polymorphism in patients with haemophilia and HCV infection: a predictor of spontaneous viral clearance and sustained virological response

Chronic hepatitis C is the main cause of morbidity and mortality in adult haemophilic patients who received non-virally inactivated plasma-derived clotting factor concentrates. Overall, spontaneous viral clearance rate is 10-25% and the only approach that can halt disease progression is hepatitis C virus (HCV) eradication by means of antiviral therapy. In non-haemophilic patients a single nucleotide polymorphism located upstream the gene of interferon lambda 3 (IFNλ3) has been associated with both spontaneous viral clearance and sustained virological response after antiviral treatment. The aim of this study was to assess whether the rs12979860 polymorphism was a predictor of spontaneous viral clearance and of sustained virological response after antiviral therapy in a large cohort of haemophilic patients with HCV infection. The rs12979860 polymorphism, defined as CC genotype or T allele, was tested in a cohort of 342 haemophilic patients and evaluated as predictor of spontaneous clearance or response to antiviral therapy. By multivariate regression analysis the IFNλ3 CC genotype was an independent predictor of spontaneous viral clearance (odds ratio: 3.7, 95% confidence interval: 2.0-6.8). Sustained virological response rates were doubled in patients with the CC genotype than in those with the T allele (78% vs 44%; p<0.001), especially in patients with HCV type 1 (67% vs 32%; p<0.001) and higher sustained response rates were observed in patients with the CC genotype who did not achieve rapid virological response (61% vs 30% in T allele patients; p=0.006).

Hepatitis B and C in African Americans: current status and continued challenges

Viral hepatitis remains a public health concern in the United States, resulting in excess morbidity and mortality for the individual and representing a burden to societies as evidenced by billions of dollars in health care expenditures. As with many chronic diseases, race and ethnicity influence various aspects of disease pathogenesis, including mechanisms of persistence, disease progression, disease sequelae, and response to therapy. For hepatitis B and C infections, African Americans disproportionately bear a large burden of disease in the United States. The role and importance of African American race, however, have been less well-characterized in the literature among the population of viral hepatitis-infected individuals. The differences in epidemiology, manifestations of liver disease, response to therapy, and differential trends in liver transplantation in African Americans compared with other racial and ethnic groups deserve special attention. This review will address the current status of hepatitis B and C infection in African Americans in the United States and identify some of the remaining challenges in diagnosis, characterization of natural history, and treatment. For the purposes of this review, the terms African American and black will be used interchangeably throughout the text.

A comparison of modified directly observed therapy to standard care for chronic hepatitis C

Hepatitis C virus (HCV) is the most common chronic blood-borne infection in the United States. Effective treatments are available, however adherence to treatment is challenging. Modified directly observed therapy (mDOT) with weekly administration of pegylated interferon might improve adherence and outcomes for patients infected with chronic HCV. The purpose of this study was to compare two treatment protocols and examine predictors of sustained virologic response (SVR). This retrospective review compares HCV treatment outcomes in two outpatient clinics at an urban academic medical center. Gastroenterology fellows provided standard treatment (SC) in one clinic; a nurse practitioner administered weekly pegylated interferon injections weekly in a primary care clinic. All patients received oral ribavirin. Data was extracted from the medical records of all treated patients over a 5-year period. 155 treatment-naïve, chronically infected HCV patients were treated. Ninety-seven patients received mDOT treatment and 58 received standard care. Mean age was 46 years. Genotype 1 represented 59 % of the sample. The mDOT patients were significantly more likely to be younger (44 vs. 50 years), have a history of injection drug use (93.1 vs. 50.0 %), and be HIV-infected (13.5 vs. 2 %) compared to SC patients. The overall SVR rate was 45.2 % and did not differ between the groups in unadjusted analyses (p = 0.95). Genotype was the only predictor of SVR. Patients treated by nurse practitioners trained in HCV care and seen weekly for interferon injections have comparable treatment outcomes to patients treated by specialists.

Admixture analysis of spontaneous hepatitis C virus clearance in individuals of African descent

Hepatitis C virus (HCV) infects an estimated 3% of the global population with the majority of individuals (75-85%) failing to clear the virus without treatment, leading to chronic liver disease. Individuals of African descent have lower rates of clearance compared with individuals of European descent and this is not fully explained by social and environmental factors. This suggests that differences in genetic background may contribute to this difference in clinical outcome following HCV infection. Using 473 individuals and 792,721 single-nucleotide polymorphisms (SNPs) from a genome-wide association study (GWAS), we estimated local African ancestry across the genome. Using admixture mapping and logistic regression, we identified two regions of interest associated with spontaneous clearance of HCV (15q24, 20p12). A genome-wide significant variant was identified on chromosome 15 at the imputed SNP, rs55817928 (P=6.18 × 10(-8)) between the genes SCAPER and RCN. Each additional copy of the African ancestral C allele is associated with 2.4 times the odds of spontaneous clearance. Conditional analysis using this SNP in the logistic regression model explained one-third of the local ancestry association. Additionally, signals of selection in this area suggest positive selection due to some ancestral pathogen or environmental pressure in African, but not in European populations.

Individualization of chronic hepatitis C treatment according to the host characteristics

Hepatitis C virus (HCV) infection is a global health problem that affects more than 170 million people worldwide. It is a major cause of cirrhosis and hepatocellular carcinoma, making the virus the most common cause of liver failure and transplantation. The standard-of-care treatment for chronic hepatitis C (CHC) has been changed during the last decade and direct acting antiviral drugs have already been used. Besides, understanding of the pathogenesis of CHC has evolved rapidly during the last years and now several host factors are known to affect the natural history and response to treatment. Recent genome-wide association studies have shown the important role of interleukin-28B and inosine triphosphatase in HCV infection. The present review article attempts to summarize the current knowledge on the role of host factors towards individualization of HCV treatment.

Clinical Pharmacogenetics Implementation Consortium (CPIC) guidelines for IFNL3 (IL28B) genotype and PEG interferon-α-based regimens

Pegylated interferon-α (PEG-IFN-α or PEG-IFN 2a and 2b)- and ribavirin (RBV)-based regimens are the mainstay for treatment of hepatitis C virus (HCV) genotype 1. IFNL3 (IL28B) genotype is the strongest baseline predictor of response to PEG-IFN-α and RBV therapy in previously untreated patients and can be used by patients and clinicians as part of the shared decision-making process for initiating treatment for HCV infection. We provide information regarding the clinical use of PEG-IFN-α- and RBV-containing regimens based on IFNL3 genotype.

Role of IL28B for chronic hepatitis C treatment toward personalized medicine

Genome-wide association studies recently revealed that certain interleukin-28B (IL28B) polymorphisms are strongly associated with responses to pegylated interferon (PEG-IFN) and ribavirin (RBV) therapy in patients chronically infected with hepatitis C virus (HCV) genotype 1, as well as with spontaneous clearance of HCV. Subsequent reports revealed that IL28B genotypes also affect treatment efficacy in chronic infection with other HCV genotypes. Furthermore, there have been several reports that implicate IL28B genotypes in inflammatory status, progression of fibrosis and adverse clinical outcomes in chronic hepatitis C (CHC). Therapy of CHC recently entered a new era with the deployment of direct-acting antivirals. These include nonstructural 3/4A protease inhibitors which have shown promise in combination with PEG-IFN/RBV in several clinical trials. IFN-free therapy is expected to be useful especially in IFN-resistant patients and may become the standard of care in the future. Several clinical trials have revealed an association between IL28B genotype and treatment efficacy in triple therapy or IFN-free regimens. On the other hand the mechanism of the effect of IL28B on HCV infection has not yet been elucidated. Recently, it was shown that the polymorphism of IFN-lambda 4 (IFNL4) is in high linkage disequilibrium with that of near IL28B, and more strongly associated with spontaneous or treatment-induced HCV clearance than IL28B genotypes, especially in individuals of African ancestry. This finding provides new insights into the genetic regulation of HCV clearance and its clinical management. IL28B genotyping will be also useful for personalized CHC treatment in the forthcoming era of direct-acting antivirals.

Individualized therapy for hepatitis C infection: focus on the interleukin-28B polymorphism in directing therapy

Hepatitis C virus—a major global cause of chronic hepatitis, cirrhosis, and hepatocellular carcinoma—affects millions of people worldwide. Pegylated interferon (Peg-IFN) and ribavirin (RBV) had been the standard treatment for a decade until availability of the protease inhibitors in 2011. However, current antiviral therapy is still IFN-based and is associated with significant side effects and variable treatment response. Thus, various host and viral factors have been evaluated before and during treatment for the prediction of sustained virologic response to antiviral therapy. In 2009, genome-wide association studies found the single-nucleotide polymorphisms, located near the host interleukin-28B (IL28B) gene that encodes IFN-λ3, to be the best pretreatment predictor of virologic response to Peg-IFN and RBV therapy in chronic hepatitis C genotype 1 patients. Additionally, inosine triphosphatase (ITPA) gene variants were found to be associated with RBV-induced hemolytic anemia, which could affect treatment dose for selected patients. IL28B, ITPA, and other treatment predictors allowed for a potential individualized approach to treat hepatitis C. In the era of increased overall virologic response rates and good tolerability of the rapidly developing non-IFN oral direct-acting antiviral therapy regimens, the need for individualized treatment is likely to diminish. Various predictors of response, including IL28B will likely be of reduced importance in the near future.

Comparative analysis of rs12979860 SNP of the IFNL3 gene in children with hepatitis C and ethnic matched controls using 1000 Genomes Project data

The rs12979860 single nucleotide polymorphism located on chromosome 19q13.13 near the interferon L3 gene (formerly and commonly known as interleukin 28B gene) has been associated in adults with both spontaneous and treatment induced clearance of hepatitis C virus. Although the exact mechanism of these associations remains unclear, it suggests that variation in genes involved in the immune response against the virus favours viral clearance. Limited and preliminary data are available on this issue in children. The aim of the present study was to evaluate, in a representative cohort of children with perinatal infection, the potential association between rs12979860 single nucleotide polymorphism and the outcome of hepatitis C virus infection. Alleles and genotypes frequencies were evaluated in 30 children who spontaneously cleared the virus and in 147 children with persistent infection and were compared with a population sample of ethnically matched controls with unknown hepatitis C status obtained using the 1000 Genomes Project data. The C allele and the C/C genotype showed greater frequencies in the clearance group (76.7% and 56.7%, respectively) when compared with both children with viral persistence (C allele 56.5%, p = 0.004; C/C genotype 32.7%, p = 0.02) and with the ethnically matched individuals (C allele 59.7%, p = 0.02; C/C genotype 34.7%, p = 0.03). Children with the C/C genotype were 2 times more likely to clear hepatitis C virus relative to children with the C/T and T/T genotypes combined (odds ratio: 2.7; 90% confidence intervals: 1.3-5.8). The present study provides the evidence that the rs12979860 single nucleotide polymorphism influences the natural history of hepatitis C virus in children.

Pegylated IFN-α and ribavirin: emerging data in the treatment of special populations

Hepatitis C virus (HCV) is one of the most common causes of chronic liver disease and is currently the leading indication for liver transplantation in the USA. Pegylated IFN-α (PEG-IFN-α) and ribavirin comprise the standard of care for the treatment of chronic HCV. The expansion of antiviral therapy to include special populations that were not well represented or excluded from registration trials has occurred in recent years. Data have emerged that demonstrate that these groups have variable responses to therapy and, in some cases, different side-effect profiles. The etiologies for the varied response rates remain under investigation. This review will address the clinical efficacy and safety profiles of PEG-IFN-α and ribavirin in populations of patients coinfected with HIV, obese patients, liver transplant recipients, children and African-Americans.

Viral evolution explains the associations among hepatitis C virus genotype, clinical outcomes, and human genetic variation

Specific human polymorphisms, most commonly found in Central Africa, can predict the success of drug treatment against the hepatitis C virus (HCV), a significant and globally-distributed human pathogen. However, this association is only found for a subset of HCV genotypes. Despite receiving considerable attention in the medical and virological literature, no evolutionary explanation for this curious pattern has been put forward. Here we suggest that the 'drug treatment resistance' phenotype exhibited today by some HCV genotypes evolved hundreds to thousands of years ago in response to human genetic variation local to Central Africa: an adaptation that has since accrued a new function in the era of anti-viral drug treatment. This could represent one of the oldest known examples of viral exaptation at the population level.

Role of hepatitis C virus substitutions and interleukin-28B polymorphism on response to peginterferon plus ribavirin in a prospective study of response-guided therapy

Recent studies have indicated that amino acid (aa) substitutions in the core region and NS5A interferon sensitivity-determining region (ISDR) of hepatitis C virus (HCV) as well as genetic polymorphisms in the interleukin-28B (IL-28B) locus affect the outcome of interferon (IFN)-based therapies. We aimed to investigate the role of these factors on response to peginterferon plus ribavirin in a prospective study of response-guided therapy. The aa sequences in core region and ISDR and rs12979860 genotypes were analysed in 115 HCV-1 patients. The treatment was 24 weeks for patients achieving a rapid virological response (RVR), 48 weeks for those with an early virological response (EVR) and early terminated in those without an EVR. A sustained virological response (SVR) was achieved in 82% of 34 RVR patients, 45% of 74 EVR patients and 0% of seven non-EVR patients. Logistic regression analysis showed that ISDR mutation (≥2) [odds ratio(OR): 6.024], double core 70/91 mutations (OR: 0.136), and platelet counts≥15×10(4) /μL (OR: 3.119) were independent pretreatment factors associated with SVR. Apart from rs12979860 CC genotype, low viral load and ISDR mutation (≥2) were significant factors predictive of RVR. Combination of rs12979860 genotype and baseline viral characteristics (viral load and core/ISDR mutations) could predict RVR and SVR with positive predictive value of 100% and 91%, and negative predictive value of 80% and 54%, respectively. In conclusion, pretreatment screening rs12979860 genotype and aa substitutions in the core region and ISDR could help identifying patients who are good candidates for peginterferon plus ribavirin therapy.

Advances in the Diagnosis and Monitoring of Hepatitis C Virus Infection

Hepatitis C virus (HCV) infection represents a major health problem worldwide. Approximately 350,000 people die every year from hepatitis C related diseases. Antiviral therapy is given to prevent such complications. Advances in serological and molecular assays greatly improved the diagnosis of hepatitis C virus infection and the management of chronically infected patients. Sensitive real-time PCR methods are currently used to monitor the response to antiviral therapy, to guide treatment decisions, and to assess the sustained virological response 24 weeks after the end of therapy. HCV genotyping is part of the pretreatment evaluation. Determination of HCV genotype is important both for tailoring antiviral treatment and for determining treatment duration. It predicts also response to therapy. With the recent introduction of the serine protease inhibitors telaprevir and boceprevir, approved for the treatment of genotype 1 chronic hepatitis C in combination with INF-a and ribavirin, subtyping has become clinically relevant. Indeed, subtypes 1a and 1b may respond differently to current telaprevir-based or boceprevir-based triple therapy. This review summarizes the most recent advances in the diagnosis and monitoring of HCV chronic infection.

Impaired HCV clearance in HIV/HCV coinfected subjects treated with PegIFN and RBV due to interference of IFN signaling by IFNαR2a

Enhanced endogenous interferon (IFN) stimulated gene (ISG) signature has been associated with nonresponsiveness to hepatitis C treatment using pegylated-IFNα (pegIFNα) and ribavirin (RBV) in human immunodeficiency virus/hepatitis C virus (HIV/HCV) coinfected patients. Using a proteomic approach, we identified high levels of IFNα receptor 2a (IFNαR2a) in the serum of null responders to pegIFNα/RBV. IFNαR2a inhibited antiviral activity of all formulations of IFNα in JFH/Huh7.5 cells. Furthermore, serum from null responders, but not from those who achieved sustained virologic response, suppressed IFN-signaling and ISG expression in IFNα-stimulated PBMCs of healthy donors in an IFNαR2a specific fashion. An IFNαR2a transgenic mice model (C57BL/6) was generated that had significantly higher levels of IFNαR2a in the serum than the controls (P=0.001). Total ISG expression in the lymph nodes was significantly higher compared to wild-type mice (P value=0.0016). In addition, IFITM1 and SP110 had significantly increased expression in the liver, IFITM1 and ISG15 in the lymph node, and ISG15 and PLSCR1 in the spleen (P value<0.05). The underlying mechanism of resistance to hepatitis C treatment may involve transsignaling of the JAK/STAT pathway by the sIFNαR2a-IFNα/β complex and result in the enhanced ISG signature observed in null responders. In this regard, the transgenic mice model simulated nonresponders to IFNα therapy and provides valuable insights into the role of sIFNαR2a-IFNα interactions in vivo.

Hepatitis C virus NS3 inhibitors: current and future perspectives

Currently, hepatitis C virus (HCV) infection is considered a serious health-care problem all over the world. A good number of direct-acting antivirals (DAAs) against HCV infection are in clinical progress including NS3-4A protease inhibitors, RNA-dependent RNA polymerase inhibitors, and NS5A inhibitors as well as host targeted inhibitors. Two NS3-4A protease inhibitors (telaprevir and boceprevir) have been recently approved for the treatment of hepatitis C in combination with standard of care (pegylated interferon plus ribavirin). The new therapy has significantly improved sustained virologic response (SVR); however, the adverse effects associated with this therapy are still the main concern. In addition to the emergence of viral resistance, other targets must be continually developed. One such underdeveloped target is the helicase portion of the HCV NS3 protein. This review article summarizes our current understanding of HCV treatment, particularly with those of NS3 inhibitors.

Donor Risk Index for African American liver transplant recipients with hepatitis C virus

African American (AA) liver transplant (LT) recipients with hepatitis C virus (HCV) have higher rates of graft loss than other racial/ethnic groups. The Donor Risk Index (DRI) predicts graft loss but is neither race- nor disease-specific and may not be optimal for assessing donor risk for AA HCV-positive LT recipients. We developed a DRI for AA with HCV with the goal of enhancing graft loss predictions. All U.S. HCV-positive adult AA first deceased donor LTs surviving ≥30 days from March 2002 to December 2009 were included. A total of 1,766 AA LT recipients were followed for median 2.8 (interquartile range [IQR] 1.3-4.9) years. Independent predictors of graft loss were donor age (40-49 years: hazard ratio [HR] 1.54; 50-59 years: HR 1.80; 60+ years: HR 2.34, P < 0.001), non-AA donor (HR 1.66, P < 0.001), and cold ischemia time (CIT) (HR 1.03 per hour >8 hours, P = 0.03). Importantly, the negative effect of increasing donor age on graft and patient survival among AAs was attenuated by receipt of an AA donor. A new donor risk model for AA (AADRI-C) consisting of donor age, race, and CIT yielded 1-year, 3-year, and 5-year predicted graft survival rates of 91%, 77%, and 68% for AADRI <1.60; 86%, 67%, and 55% for AADRI 1.60-2.44; and 78%, 53%, and 39% for AADRI >2.44. In the validation dataset, AADRI-C correctly reclassified 27% of patients (net reclassification improvement P = 0.04) compared to the original DRI.

CONCLUSION

AADRI-C identifies grafts at higher risk of failure and this information is useful for risk-benefit discussions with recipients. Use of AA donors allows consideration of older donors.

Preparing the patient for success: treat or wait?

Hepatitis C is a frequent cause of liver cirrhosis and, hepatocellular carcinoma worldwide. However, predicting clinical outcomes in patients with chronic hepatitis C is challenging. The risk of disease progression is not linear and can be associated with several factors. With the currently available therapies, around 70% of naïve patients, independently of hepatitis C virus genotype can achieve a sustained virologic response. Consequently, all hepatitis C virus patients are candidates for antiviral therapy. The decision to treat a patient with chronic hepatitis C virus infection is based on several factors, including the natural history of the disease, the stage of fibrosis, and the efficacy and adverse effects related to therapy. The decision to treat immediately or wait for a new drug is more difficult and should be tailored to each patient, taking into account the patient's characteristics, the risk of disease progression, the patient's wishes, and the experience of the attending physician.

Future therapies for chronic hepatitis C

Therapy for hepatitis C has been fairly stagnant for the past decade, but the past few years have seen major progress and evolution, beginning with the approval of two HCV protease inhibitors in 2011. In spite of considerable improvements in response rates with these agents, a need for additional agents with improved potency and tolerability remains. Toward this goal and over the course of just a few months, the HCV therapy pipeline has already become crowded with direct-acting antivirals, host-targeted agents and unique interferons, all of which are positioned to be part of the next wave of therapeutic options. The ultimate goal of this push for new agents is to achieve a safe and straight forward yet highly effective therapy for hepatitis C that is widely embraced and readily available. Particularly among the 'baby boomer' population, it is predicted that over the next few years, more patients with currently quiescent infections will be newly diagnosed, and those currently diagnosed will be at increased risk of long-term complications of infection, and thus in need of treatment. A simple and safe treatment paradigm will become a necessity. This Review chronicles the latest developments in hepatitis C therapy and the potential effect these new treatments could have on delivery of care to patients infected with HCV.

Boceprevir for previously untreated patients with chronic hepatitis C Genotype 1 infection: a US-based cost-effectiveness modeling study

BACKGROUND

SPRINT-2 demonstrated that boceprevir (BOC), an oral hepatitis C virus (HCV) nonstructural 3 (NS3) protease inhibitor, added to peginterferon alfa-2b (P) and ribavirin (R) significantly increased sustained virologic response rates over PR alone in previously untreated adult patients with chronic HCV genotype 1. We estimated the long-term impact of triple therapy vs. dual therapy on the clinical burden of HCV and performed a cost-effectiveness evaluation.

METHODS

A Markov model was used to estimate the incidence of liver complications, discounted costs (2010 US$), quality-adjusted life years (QALYs), and incremental cost-effectiveness ratios (ICERs) of three treatment strategies for treatment-naïve patients with chronic HCV genotype 1. The model simulates the treatment regimens studied in SPRINT-2 in which PR was administered for 4 weeks followed by: 1) placebo plus PR for 44 weeks (PR48); 2) BOC plus PR using response guided therapy (BOC/RGT); and 3) BOC plus PR for 44 weeks (BOC/PR48) and makes projections within and beyond the trial. HCV-related state-transition probabilities, costs, and utilities were obtained from previously published studies. All costs and QALYs were discounted at 3%.

RESULTS

The model projected approximately 38% and 43% relative reductions in the lifetime incidence of liver complications in the BOC/RGT and BOC/PR48 regimens compared with PR48, respectively. Treatment with BOC/RGT is associated with an incremental cost of $10,348 and an increase of 0.62 QALYs compared to treatment with PR48. Treatment with BOC/PR48 is associated with an incremental cost of $35,727 and an increase of 0.65 QALYs compared to treatment with PR48. The ICERs were $16,792/QALY and $55,162/QALY for the boceprevir-based treatment groups compared with PR48, respectively. The ICER for BOC/PR48 compared with BOC/RGT was $807,804.

CONCLUSION

The boceprevir-based regimens used in the SPRINT-2 trial were projected to substantially reduce the lifetime incidence of liver complications and increase the QALYs in treatment-naive patients with hepatitis C genotype 1. It was also demonstrated that boceprevir-based regimens offer patients the possibility of experiencing great clinical benefit with a shorter duration of therapy. Both boceprevir-based treatment strategies were projected to be cost-effective at a reasonable threshold in the US when compared to treatment with PR48.

Physical, social, and psychological consequences of treatment for hepatitis C : a community-based evaluation of patient-reported outcomes

BACKGROUND

Hepatitis C virus (HCV) antiviral therapy entails a long treatment course, as well as significant side effects that can lead to medication non-adherence and premature termination of treatment. Few large studies have comprehensively examined patient perspectives on the treatment experience, particularly the social and personal effects.

OBJECTIVE

We sought to understand how a diverse group of patients' lives were affected during HCV treatment, and to obtain suggestions about how to better support patients during treatment.

METHODS

On average, 13 months after therapy we interviewed by telephone a consecutive sample of 200 patients treated for hepatitis C with ribavirin and pegylated interferon in a comprehensive, integrated health plan in the years 2008-2010. Mixed (quantitative and qualitative) survey methods were used.

RESULTS

The response rate was 68.9 %. Mean age at treatment was 51 years; 63.0 % were men; and Black, Hispanic, Asian, and White non-Hispanic racial/ethnic groups were similarly represented. Patients whose treatment was managed by nurses or clinical pharmacists (vs. physicians) were more likely to report their providers as being part of their support system (83.5 % vs. 58.9 %; p < 0.001). Most patients reported flu-like symptoms (93.5 %) and psychiatric problems (84.5 %), and 42.5 % reported side effects lasted up to 6 months after treatment. Black patients reported discontinuing treatment prematurely due to side effects more often than non-Blacks (29.4 % vs. 12.1 %; p < 0.001). Physical side effects (69.5 % of patients), psychiatric issues (43.5 %), and employment (27.4 %) were ranked among the three most difficult challenges. Patients desired help in anticipating and arranging work modifications during treatment. Most patients rated peer support, nutritional guidance, and weekly provider contact by telephone as potentially helpful resources for future patients undergoing HCV treatment.

CONCLUSIONS

Patient perspectives can help formulate and refine HCV treatment support programs. Effective support programs for diverse populations are crucial as the complexities and costs of HCV treatment increase. The call for greater support from peers, providers, and employers demands new systems such as patient-centered care teams.

Treatment of hepatitis C virus infection in the future

Two direct-acting antivirals (DAAs) against hepatitis C virus (HCV): telaprevir and boceprevir, are now available in combination with peginterferon plus ribavirin for the treatment of chronic hepatitis C infection. Although these drugs are potent inhibitors of HCV replication, they occasionally result in severe adverse events. In the present clinical trials, in their stead, several second-generation DAAs are being investigated. Most of them are being viewed with high expectations, but they also require the combination with peginterferon plus ribavirin. In the near future, we might be using all-oral DAAs and interferon-free regimens for the treatment of HCV-infected patients, and these would be potent inhibitors of HCV and have less adverse events.

Neutropenia during therapy with peginterferon and ribavirin in HIV-infected subjects with chronic hepatitis C and the risk of infections

BACKGROUND

It is unclear whether pegylated interferon (peg-IFN) -induced neutropenia in subjects coinfected with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) is associated with increased risk of serious infections.

METHODS

This was a prospective cohort study conducted between 2000 and 2012 in HIV/HCV-coinfected subjects initiating treatment with peg-IFN plus ribavirin (RBV). Infections were defined as serious when patients required hospitalization, treatment was discontinued, or the patient died. The association between neutropenia (severe, <500 cells/μL; nonsevere, 500 -1500 cells/μL) and infections (serious infections and infections of any severity) was determined by logistic regression analysis.

RESULTS

Among 418 subjects (3928 person-weeks of therapy), infections occurred in 123 (29%), accounting for 149 episodes (3.8 infections per 100 person-weeks of therapy). Most infections (47%) involved the upper respiratory tract and were minor. After a multivariate analysis adjusted by age, sex, CD4 count, AIDS, antiretroviral therapy, cirrhosis, neutrophil count, type of peg-IFN, and granulocyte colony-stimulating factor use, none of these variables remained independently associated with the risk of infection. Twenty subjects developed a serious infection (4.8% of all patients). The frequency of serious infections was higher in subjects with severe neutropenia compared to those with nonsevere neutropenia and without neutropenia, although it was not statistically significant (8.6%, 4.8%, and 3.6%, respectively; trend test P = .281). In multivariate analysis, neutropenia was not independently associated with increased risk of serious infections.

CONCLUSIONS

In this large prospective cohort of HIV/HCV-coinfected patients treated with peg-IFN plus RBV, serious infections were uncommon, nonfatal, and unrelated to peg-IFN -induced severe neutropenia.

The impact of ethnicity on hepatitis C virus treatment decisions and outcomes

Hepatitis C virus infection is a major public health concern. Approximately 4 million people are reported to be infected with the virus in the United States, and the annual death rate due to HCV-associated decompensated liver failure or hepatocellular carcinoma is estimated to be approximately 18,000 within the next decade. Therapeutic success, as measured by a sustained virologic response, is approximately 50 % in G1 patients with pegylated-interferon/ribavirin-based therapies. Independent studies have reported significant variation in response rates depending on the ethnicity or race of the patient, though the underlying reasons are not well understood. Historically, ethnic populations have been underrepresented in most large clinical trials of HCV therapies, even though these populations have disproportionately high rates of HCV infection. Recent clinical trials have investigated genetic variations in key biological pathways that may underlie the mechanisms responsible for the different rates of HCV clearance and treatment outcomes in ethnic populations treated with pegylated-interferon/ribavirin. However, as novel direct-acting antiviral drugs are added to, and eventually replace, existing treatment regimens, the role of the innate immune response in determining treatment outcomes will diminish. Socioeconomic and biological factors can impact rates of HCV infection, disease progression, and treatment outcomes in minority populations. Improved access to health care, novel antiviral treatments, and a better understanding of the host factors that contribute to disparities in treatment outcomes are expected to result in optimized treatment paradigms that directly target the virus, leading to improved outcomes for all patients.

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

BACKGROUND AND GOAL

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

STUDY

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

RESULTS

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

CONCLUSIONS

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

The role of patient religiosity in the evaluation and treatment outcomes for chronic HCV infection

To determine the influence of patient religiosity on the outcome of treatment of hepatitis C infection, a prospective, blinded, cohort study was performed on hepatitis C-infected patients categorized as 'higher religiosity' and 'lower religiosity' based on responses to a religiosity questionnaire. Comparisons were made between high and low religiosity patients on demographics, pre-treatment laboratory values, and response to treatment. Eighty-seven patients with complete questionnaires were placed in either higher (38) or lower (49) religiosity cohort. The patients (60% female) were ethnically diverse: African-American 39%; Hispanic 31%; white 29%. African-American race (P = 0.001) and female gender (P = 0.026) were associated with higher religiosity. The frequency of being offered treatment, accepting treatment, and completing treatment was similar in both religiosity cohorts (P = 0.234, 0.809, 0.367). Fifty-six patients completed the 24- or 48-week treatment with peginterferon and ribavirin. Depression was more frequent in the low religiosity group (38.2% vs. 4.6%, P = 0.005). Sustained viral response rate at 3-6-month post-therapy was similar in the higher (50%) and lower (57.6%) religiosity cohorts (P = 0.580; n = 55). Logistic regression modeling revealed that males having higher religiosity gave greater odds of SVR than those with lower religiosity (OR 21.3; 95% CI 1.1-403.9). The level of religiosity did not affect the decision to begin treatment for chronic HCV infection and was not associated with a better treatment outcome. A higher level of religiosity was associated with less depression among patients.

Telaprevir versus boceprevir in chronic hepatitis C: a meta-analysis of data from phase II and III trials

BACKGROUND

Telaprevir and boceprevir are protease inhibitors now added to therapy for patients with chronic hepatitis C virus (HCV) genotype 1 infection who either are treatment naive or have a history of relapse or recurrence following a previous course of treatment with pegylated interferon + ribavirin (Peg-IFN + RBV). Because these agents are fairly new to the market, providers may have limited experience with them in the management of chronic HCV.

OBJECTIVE

This meta-analysis compared 24- and 48-week sustained viral responses (SVR) and drug-related adverse events (AEs) between telaprevir and boceprevir triple-therapy regimens in the treatment of chronic HCV infection.

METHODS

MEDLINE, EMBASE, and Cochrane databases were searched for articles published from January 1995 to October 2012 on randomized controlled trials that reported SVR at ≥24 weeks in patients with HCV receiving triple-therapy regimens that included telaprevir or boceprevir or placebo + pegylated interferon + ribavirin (Peg-IFN + RBV). Pooled odds ratios (ORs) were calculated and used to compare SVR at 24 and 48 weeks. Secondary end points included common drug-related AEs and treatment discontinuations.

RESULTS

Eight studies were included in this meta-analysis (N = 4144 treatment-naive and treatment-experienced patients). With telaprevir, the ORs (95% CI) for SVR at 24 weeks in treatment-naive and treatment-experienced patients were 3.31 (2.27-4.82; P < 0.0001) and 4.21 (1.83-9.72; P = 0.001), respectively. Telaprevir triple therapy did not result in more drug-related discontinuations but did cause additional rash, pruritis, and anemia. With boceprevir, the ORs (95% CI) were improved in both treatment-naive and treatment experienced patients (3.55 [2.66-4.56; P < 0.0001] and 7.34 [3.92-13.9; P < 0.0001]), but with more treatment-related anemia and dysgeusia.

CONCLUSIONS

Based on the findings from this meta-analysis, telaprevir or boceprevir combined with Peg-IFN + RBV had favorable short-term data on SVR while resulting in more drug-related AEs. Extended follow-up is required to determine whether these agents offer a reduction in the risk for chronic hepatitis C genotype 1-related mortality and/or hospitalization.

Distribution of hepatitis C virus genotypes in a diverse US integrated health care population

Hepatitis C virus (HCV) genotypes influence response to therapy, and recently approved direct-acting antivirals are genotype-specific. Genotype distribution information can help to guide antiviral development and elucidate infection patterns. HCV genotype distributions were studied in a diverse cross-section of patients in the Northern California Kaiser Permanente health plan. Associations between genotype and race/ethnicity, age, and sex were assessed with multivariate logistic regression models. The 10,256 patients studied were median age 56 years, 62% male, 55% White non-Hispanic. Overall, 70% were genotype 1, 16% genotype 2, 12% genotype 3, 1% genotype 4, <1% genotype 5, and 1% genotype 6. Blacks (OR 4.5 [3.8-5.5]) and Asians (OR 1.2 [1.0-1.4]) were more likely to have genotype 1 than 2/3 versus non-Hispanic Whites. Women less likely had genotype 1 versus 2/3 than did men (OR 0.86 [0.78-0.94]). Versus non-Hispanic Whites, Asians (OR 0.38 [0.31-0.46]) and Blacks (OR 0.73 [0.63-0.84]) were less likely genotype1a than 1b; Hispanics (OR 1.3 [1.1-1.5]) and Native Americans (OR 1.9 [1.2-2.8]) more likely had genotype 1a than 1b. Patients age ≥65 years less likely had genotype 1a than 1b versus those age 45-64 (OR 0.34 [0.29-0.41]). The predominance of genotype 1 among all groups studied reinforces the need for new therapies targeting this genotype. Racial/ethnic variations in HCV genotype and subtype distribution must be considered in formulating new agents and novel strategies to successfully treat the diversity of hepatitis C patients.

Revisiting the predictors of a sustained virologic response in the era of direct-acting antiviral therapy for hepatitis C virus

Several host (age, sex, race, fibrosis stage, interleukin 28B polymorphism) and viral factors (hepatitis C virus [HCV] genotype, viral load) allow estimating the response to interferon-based therapies (which includes first-generation protease inhibitors) before treatment. However, treatment should not be denied to any patient based on unfavorable factors alone. Metabolic conditions associated with poor response (diabetes, insulin resistance, obesity) and alcohol abuse can be influenced before starting treatment. "On-treatment" predictors of response allow treatment to be tailored to the individual need of the patient. Patients with undetectable HCV RNA after 4 weeks (rapid virologic response [RVR]) have the highest chance for cure (>85%) both by dual and triple therapy. For triple therapy, the decision to shorten treatment requires that the virus remains undetectable for an additional 8 (telaprevir) to 20 (boceprevir) weeks (extended RVR). Based on viral kinetics, an even earlier prediction after 2 weeks of treatment with direct acting antivirals appears feasible.

Alanine aminotransferase elevation during peginterferon alpha-2a or alpha-2b plus ribavirin treatment

Alanine aminotransferase (ALT) elevation was occassionally observed during the treatment with combination peginterferon alpha plus ribavirin. Two forms of peginterferon are currently available as a standard of care with or without direct-acting antivirals against hepatitis C virus (HCV). Until the appearance of interferon-sparing regimen, peginterferon alpha plus ribavirin will play a central role in the eradication of HCV. In the present study, we compared ALT elevations in response to peginterferon alpha-2a plus ribavirin or peginterferon alpha-2b plus ribavirin in HCV genotype-1-infected patients. There were no significant differences in ALT elevations between treatments with the two peginterferons, but in a comparison of the proportions of patients with transient ALT elevation from baseline between the two groups, transient ALT elevation was observed more in sustained virological response (SVR) patients treated with peginterferon alpha-2a than with peginterferon alpha-2b. However, no patients discontinued treatment due to ALT elevation. Patients with transient ALT elevation from baseline during the treatment had less favorable IL28B rs8099917 genotype in the peginterferon alpha-2b group. Patients achieving SVR tended to have lower ALT levels, although some had persistent ALT elevation during treatment. In conclusion, clinicians should pay attention to possible ALT elevation during the treatment of chronic hepatitis C patients.

Host factors determining the efficacy of hepatitis C treatment

Combination therapy with pegylated interferon and ribavirin is the standard of care (SOC) for the treatment of chronic hepatitis C (CHC). Treating CHC with SOC may show a sustained virological response (SVR) in approximately 50-70 % of genotype 1 CHC patients and an SVR in 70-90 % of genotype 2 CHC patients. The genotype, baseline viral load, and viral kinetics (i.e., rapid virologic response and early virologic response) can be used as predictors of response-guided therapy. Nonetheless, host factors, e.g. age, ethnicity, insulin resistance, and genetic variations, may also play important roles in the SVR in CHC patients treated with SOC. Recent genome-wide association studies have demonstrated that single-nucleotide polymorphisms near the interleukin 28B gene (IL28B) were associated with SVR to treatment with SOC in CHC patients. The IL28B polymorphisms may contribute to the viral kinetics during treatment. Asian people have favorable IL28B polymorphisms. This factor may at least partly explain the high eradication rate of hepatitis C by SOC in Asia. Combination therapy with direct-acting antivirals (DAAs) and SOC can increase the SVR rates both in treatment-naïve and treatment-experienced patients. Although the IL28B polymorphisms also affect the SVR of triple therapy with SOC and first-generation protease inhibitors, pilot studies have demonstrated that potent DAAs might overcome the influence of IL28B polymorphisms. Thus, the treatment of hepatitis C virus infection could be simplified in the near future.

Progress in research of genotypes of hepatitis C virus

Hepatitis C virus (HCV), belonging to the Flaviviridae family, is divided into six genotypes and different subtypes. There are four nomenclatures for HCV, of which the nomenclature system proposed by Simmonds et al. is widely applied overseas in recent years. HCV genotypes have obvious geographical variation and show significant epidemiological differences. Five methods are currently available for genotyping HCV, and each has its own advantages and disadvantages. HCV genotypes closely correlate with the severity, course, progression, treatment, and outcome of hepatitis C. The therapeutic effect for different HCV genotypes varies, and IL-28B polymorphism is a predictor of sustained virological response to treatment among various HCV genotypes. The diversity of HCV genotypes brings certain difficulty to vaccine development. Some success has been achieved in the development of HCV vaccine in animals. The main purpose of the present article is to review the recent progress in research of genotypes of HCV in terms of genotyping methods, associations between genotypes and epidemiological significance, severity of disease, and antiviral treatment response, and vaccine development.

Seroprevalence of Hepatitis B and C Infections among Healthy Volunteer Blood Donors in the Central California Valley

Background/Aims

The Central California Valley has a diverse population with significant proportions of Hispanics and Asians. This cross-sectional study was conducted to evaluate the prevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) in healthy blood donors in the Valley.

Methods

A total of 217,738 voluntary blood donors were identified between 2006 and 2010 (36,795 first-time donors; 180,943 repeat donors).

Results

Among the first-time donors, the HBV and HCV prevalence was 0.28% and 0.52%, respectively. Higher HBV prevalence seen in Asians (3%) followed by Caucasians (0.05%), African Americans (0.15%), and Hispanics (0.05%). Hmong had a HBV prevalence of 7.63% with a peak prevalence of 8.76% among the 16- to 35-year-old age group. Highest HCV prevalence in Native Americans (2.8) followed by Caucasians (0.59%), Hispanics (0.45%), African Americans (0.38%), and Asians (0.2%).

Conclusions

Ethnic disparities persist with regard to the prevalence of HBV and HCV in the Central California Valley. The reported prevalence may be an underestimate because our study enrolled healthy volunteer blood donors only. The development of aggressive public health measures to evaluate the true prevalence of HBV and HCV and to identify those in need of HBV and HCV prevention measures and therapy is critically important.

IL28B polymorphisms as a pretreatment predictor of response to HCV treatment

Genome-wide association studies have identified polymorphisms located near the gene encoding IL28B, which turned out to be the best predictor of response to pegylated interferon plus ribavirin for chronic hepatitis C virus (HCV) genotype 1 infection. This association was extended to spontaneous clearance of HCV, suggesting shared mechanisms of treatment and natural control of this virus. In addition to the biologic implications for innate immunity and HCV, a variety of clinical studies have suggested possible translation to a useful genetic test for practitioners. This article reviews the discovery, biology, and potential clinical applications that have stemmed from the seminal observation that IL28B polymorphisms are a main predictor of HCV clearance.

A single nucleotide polymorphism in IL28B affects viral evolution of hepatitis C quasispecies after pegylated interferon and ribavirin therapy

Interleukin-28B (IL28B) polymorphisms are associated with viral response to peginterferon and ribavirin (RBV) in chronic hepatitis C (HCV). Their recognition represents a breakthrough in the understanding of the role of the host in viral eradication. How these polymorphisms determine viral eradication is unknown. The IL-28B variants are hypothesized to have a differential impact on HCV quasispecies evolution during treatment with pegylated interferon (PEG-IFN) and RBV. In this study, HCV RNA levels were measured at early time points in 33 naïve genotype 1 hepatitis C patients and clonal analysis of the entire NS5A region was performed on sera from baseline and Day 7. Site rs12979860 polymorphisms were determined by direct sequencing of PCR products and classified into CC, CT, and TT and were identified in 13, 11, and 9 patients, respectively. The CC polymorphism more commonly was seen in Whites versus Blacks [12/21 (57%) vs. 1/12 (8%), P = 0.009] and HIV-infected versus mono-infected [13/25 (52%) vs. 0/8 (0%), P = 0.009]. Patients with CC and non-CC had similar baseline viral loads. More patients with the CC polymorphism had amino acid substitutions in NS5A compared to non-CC patients. Despite similar baseline viral diversity, by Day 7, significantly more patients with CC had higher non-synonymous substitution values compared to non-CC (P = 0.02). Chronic hepatitis C patients with the CC IL28B polymorphism have a higher number of amino acid substitutions in the NS5A region and early viral evolution due to greater interferon induced selective pressure during this critical period of treatment.

Optimum ribavirin exposure overcomes racial disparity in efficacy of peginterferon and ribavirin treatment for hepatitis C genotype 1

OBJECTIVES

Peginterferon and ribavirin treatment is less effective for hepatitis C virus (HCV) genotype 1 infections in African Americans (AA) compared with Caucasian Americans (CA). Host genetic variability near the interleukin-28B (IL28B) gene locus is partly responsible. We investigated the relationship between ribavirin drug exposure and week 24 and 72 (sustained virologic response, SVR) responses (undetected serum HCV RNA) in 71 AA and 74 CA with HCV genotype 1 who received >90% of the prescribed peginterferon and weight-based ribavirin (1,000 or 1,200 mg per day) from week 1 to 24.

METHODS

Ribavirin plasma levels were measured at weeks 1, 2, 4, 8, 12 and 24; ribavirin area under the concentration vs. time curve (AUC) was calculated using the linear trapezoidal rule.

RESULTS

Compared with CA, AA had lower week 24 (WK24VR) (57.8 vs. 78.1; P<0.05) and week 72 (SVR) (36.6% vs 54.8%; P<0.05) response rates. AA also had significantly lower ribavirin exposure (AUC) from week 1 to 12 (P<0.05). Ribavirin exposures ≥4,065 and ≥4,480 ng/ml/day in the first week (AUC(0-7)) were thresholds for WK24VR and SVR in receiver-operating characteristic curve analyses. AA were less likely to have a threshold ribavirin AUC(0-7) level than CA (P<0.05). There were no significant racial differences in WK24VR (AA: 77 vs. CA: 84%) and SVR (AA: 52 vs. CA: 60%) rates in patients who met the ribavirin AUC(0-7) thresholds. Ribavirin AUC(0-7) predicted WK24VR and SVR independently of IL28B single-nucleotide polymorphism rs12979860 genotype. Yet, achieving threshold AUC(0-7) levels increased response rates primarily in AA with the less favorable non-C/C genotypes.

CONCLUSIONS

Standard weight-based dosing leads to suboptimal ribavirin exposure in AA and contributes to the racial disparity in peginterferon and ribavirin treatment efficacy for HCV genotype 1.

Vitamin D and the racial difference in the genotype 1 chronic hepatitis C treatment response

BACKGROUND

African Americans with genotype 1 chronic hepatitis C attain a sustained virologic response (SVR) at only approximately one-half the rate of whites after peginterferon and ribavirin treatment. The serum concentration of 25-hydroxyvitamin D [25(OH)D] has recently been established as a predictor of treatment response. Therefore, the low serum concentrations of 25(OH)D found among African Americans may contribute to the low response rate; however, to our knowledge, none of the studies of vitamin D in chronic hepatitis C treatment have included a significant number of black patients.

OBJECTIVE

The objective was to compare the relation between the 25(OH)D concentration and genotype 1 chronic hepatitis C treatment response in African Americans with that in whites.

DESIGN

This cross-sectional analysis included 106 African American and 65 white patients with genotype 1 chronic hepatitis C.

RESULTS

Consistent with previous studies, we found that the SVR rate in the white patients increased significantly with an increasing serum concentration of 25(OH)D [SVR rates were 20%, 46%, and 70% for 25(OH)D serum concentrations <20, 20-35, and >35 ng/mL, respectively; P-trend = 0.008]; however, there was no relation between the SVR rate and 25(OH)D serum concentration in the African American patients [SVR rates were 32%, 28%, and 33% for 25(OH)D serum concentrations <20, 20-35, and >35 ng/mL, respectively; P-trend = 0.832]. We also found an analogous racial difference in the relation between the extent of liver fibrosis and the 25(OH)D concentration.

CONCLUSION

Racial differences in vitamin D physiology or race-specific factors that modify the effects of vitamin D may affect the immune response to genotype 1 hepatitis C virus.

Approach to the treatment-naïve patient with HCV genotype 1 infection

In May 2011, the protease inhibitors boceprevir and telaprevir were approved in combination with peginterferon-α and ribavirin for the treatment of genotype 1 chronic hepatitis C virus infection in the United States. These regimens brought substantial improvements in sustained virologic response rates, especially for treatment-naïve patients. This article reviews the approach to therapy with these genotype 1 treatment-naïve patients.

Boceprevir: a novel NS3/4 protease inhibitor for the treatment of hepatitis C

Hepatitis C virus (HCV) infection affects over 170 million people worldwide and is the most common blood-borne infection in the United States. Standard treatment with peginterferon alfa-ribavirin results in low sustained virologic response (SVR) rates in many patients, especially those who are African-American, are coinfected with human immunodeficiency virus (HIV), or have liver cirrhosis. Because of suboptimal SVR rates, new direct-acting antiviral agents that target HCV viral replication steps are in development. Boceprevir is one of the novel NS3/4A protease inhibitors that was recently approved by the U.S. Food and Drug Administration. We evaluated the literature regarding boceprevir by performing a MEDLINE search (January 1996-July 2011) to identify relevant clinical trials. Abstracts and poster and oral presentations from hepatology and HIV conferences were also reviewed. Potent anti-HCV activity was seen in clinical trials with boceprevir when it was studied in HCV genotype 1-infected patients who were naïve to or had experience with HCV therapy. Data with boceprevir in HIV-HCV-coinfected patients are currently lacking; however, initial data on drug-drug interactions between boceprevir and antiretrovirals have become available. Resistance to boceprevir has been evaluated in trials as well, although more data are needed in this area. The most common adverse events with boceprevir included anemia and dysgeusia. Based on available data, boceprevir is one of the promising novel direct-acting antiviral agents that will likely reshape the treatment of patients with HCV infection.

Telaprevir and boceprevir in African Americans with genotype 1 chronic hepatitis C: implications for patients and providers

Telaprevir and boceprevir have received US Food and Drug Administration approval for use as triple therapy with pegylated interferon and ribavirin in genotype 1 chronic hepatitis C virus (HCV) infection. Clinical trials of these agents included few African Americans, despite the overwhelming need for improved therapies in this racial group. Although African Americans are predicted to have improved response rates with this new treatment paradigm, clinical trials illustrate lower rates of sustained virologic response for this racial group versus whites. African Americans with genotype 1 HCV infection appear to require longer durations of therapy than do whites to achieve a sustained virologic response. Further investigation is required to adequately counsel African Americans with genotype 1 chronic HCV infection on the efficacy of telaprevir and boceprevir in their racial group. Increased participation of this racial group in HCV clinical trials is needed to improve therapies in this difficult-to-treat population.

Evaluation and treatment of hepatitis C in patients with human immunodeficiency virus

OBJECTIVES

The rate of treatment of hepatitis C virus (HCV) infection in human immunodeficiency virus-hepatitis C virus (HIV-HCV) co-infected patients remains historically low. We undertook a retrospective study to review our treatment rate and factors that have negatively influenced this rate. In those treated, we reviewed outcomes and compared results with prior studies.

METHODS

A total of 233 patients infected with HIV and HCV were followed for 7 years in the infectious diseases (ID) clinic of East Carolina University. Proper follow-up evaluation was determined based on the presence of HCV polymerase chain reaction viral load and genotype testing. The number of patients treated, response to treatment, and reason for no treatment were determined by chart review.

RESULTS

Of 233 patients with positive HCV serology, 48 were excluded due to undetectable HCV viral load. Of the remaining 185 patients, 142 (77%) were evaluated by testing for HCV viral load and genotype, but only 112 of those who were followed up in the clinic regularly were considered eligible for therapy. Fourteen of 112 (12.5%) of patients underwent treatment and only 1 in 14 (7%) attained sustained virological response (SVR). Of the patients tested, 96% had HCV genotype 1, and 81% were African American.

CONCLUSIONS

The majority of our HIV-HCV co-infected patients received a proper HCV evaluation, but only 12.5% were offered therapy. Of those treated, only one patient achieved SVR. The higher proportion of genotype 1 and African American patient population are considered the main reasons for the low SVR. Low SVR rate, high rate of adverse effects, and the unique demography of our patient population have been the main reasons for the lower treatment rate.