Glecaprevir/pibrentasvir for the treatment of chronic hepatitis C: design, development, and place in therapy.

Direct-acting antiviral (DAA) therapy has changed the landscape of hepatitis C virus (HCV) management and has changed the focus to the possibility of HCV elimination in the near future. Glecaprevir, an NS3/4A protease inhibitor, and pibrentasvir, an HCV NS5A inhibitor, have addressed many of the existing shortcomings in the DAA therapy spectrum. This combination has proven to be a highly efficacious pan-genotypic DAA with a high barrier to resistance as a once-daily, all-oral medication. This review explores the design and development of glecaprevir and pibrentasvir, its place in current HCV management in the midst of a myriad of DAA therapy options, and also remaining challenges.

Novel educational interventions in residency increase knowledge of chronic liver disease and career interest in hepatology.

There is an increasing burden of chronic liver disease (CLD) in the United States but a significant shortage of hepatologists. Thus, it is necessary to develop new recruitment strategies to the field of hepatology as well as ensure that non-gastroenterology-trained physicians are able to capably assist in the care of CLD. We established a novel, nonelective, inpatient hepatology rotation that uses required modules in the American Association for the Study of Liver Diseases Curriculum and Training-First Hepatitis B and C curriculums as well as in LiverLearning. A paper-based anonymous assessment was distributed to the inaugural 25 postgraduate years 2 and 3 internal medicine residents before and after the 2-week rotation over the course of 1 year. Both the prerotation and postrotation assessments included validated multiple-choice questions and Likert-type questions, which evaluated self-perceived knowledge and comfort with managing CLD. The mean comfort level (1 = not at all comfortable/strongly disagree, 5 = very comfortable/strongly agree) of managing several common liver diseases increased significantly after completion of the rotation (i.e., cirrhosis 2.8 versus 3.8, P < 0.001; hepatitis B 2.4 versus 3.4, P = 0.001; hepatitis C 2.6 versus 3.7, P = 0.002; nonalcoholic steatohepatitis 3.0 versus 4.0, P < 0.001; liver transplant care 2.1 versus 3.4, P < 0.001). There was also a significantly increased interest in hepatology as a career (2.6 versus 3.0, P = 0.03). Finally, the mean percentage of multiple-choice questions answered correctly on the pretest was 62% and posttest was 77% (P = 0.02). CONCLUSION: Our novel curriculum and nonelective hepatology rotation has effectively demonstrated improvement in internal medicine residents' comfort with and knowledge of CLD, and increased career interest in hepatology was also observed after completion of the curriculum, which suggests that more exposure to CLD could positively impact recruitment to the workforce; larger, multicenter studies are needed to validate these results. (Hepatology 2016;64:2210-2218).

Generic medications for hepatitis C.

The recent development and approval of expensive but highly effective oral agents against hepatitis C has led to restrictions and access limitations in many countries with limited healthcare budgets. Generic formulations of many of these agents are available at a fraction of the retail price in several countries because of generic licensure agreements. The discounted alternatives are only accessible in developing countries and require manufacturing and distribution regulations to ensure the quality and bioequivalence of the new drug formulations. The continued medication access limitations have driven great interest in the practice of personal drug importation of the generic formulations. This review and debate will address the medical and legal issues involved in the purchase and importation of these medicines.

Faldaprevir, pegylated interferon, and ribavirin for treatment-naïve HCV genotype-1: pooled analysis of two phase 3 trials.

INTRODUCTION & AIM: Faldaprevir is a potent once-daily (q.d.) hepatitis C virus (HCV) NS3/4A protease inhibitor. The STARTVerso1 and STARTVerso2 phase 3 studies evaluated faldaprevir plus peginterferon alfa-2a/ribavirin (PegIFN/RBV) in treatment-naïve patients with chronic HCV genotype-1 infection. MATERIAL AND METHODS: Patients were randomized 1:2:2 to receive placebo, faldaprevir 120 mg q.d. (12 or 24 weeks) or faldaprevir 240 mg q.d. (12 weeks) all with PegIFN/RBV (24-48 weeks). Faldaprevir 120 mg for 12 weeks only (STARTVerso1 only) required early treatment success (ETS, HCV RNA < 25 IU/mL at week 4 and undetected at week 8). All faldaprevir-treated patients with ETS stopped PegIFN/RBV at week 24. Primary endpoint: sustained virologic response 12 weeks post-treatment (SVR12). RESULTS: SVR12 rates were significantly higher for patients treated with faldaprevir 120 or 240 mg (72% and 73%, respectively) compared with placebo (50%); estimated differences (adjusted for trial, race, and genotype-1 subtype) faldaprevir 120 mg 24% (95% CI: 17-31%, P < 0.0001), faldaprevir 240 mg 23% (95% CI: 16-30%, P < 0.0001). Subgroup analyses consistently showed higher SVR12 rates for patients receiving faldaprevir compared with placebo. The incidence of adverse events (AEs) was similar in faldaprevir 120-mg and placebo groups and slightly higher in the faldaprevir 240-mg group. Serious Aes were reported in 6%, 7%, and 8% of patients in placebo, faldaprevir 120-mg, and faldaprevir 240-mg groups, respectively. CONCLUSION: Addition of faldaprevir to PegIFN/RBV increased SVR12 in patients with HCV genotype-1, and was well tolerated. Faldaprevir 120 mg is effective in the treatment of HCV genotype-1. ClinicalTrials.gov: NCT01343888 and NCT01297270.

Retinoid and carotenoid status in serum and liver among patients at high-risk for liver cancer.

BACKGROUND: Approximately 2.7 million Americans are chronically infected with hepatitis C virus (HCV). HCV patients with cirrhosis form the largest group of persons at high risk for hepatocellular carcinoma (HCC). Increased oxidative stress is regarded as a major mechanism of HCV-related liver disease progression. Deficiencies in retinoid and carotenoid antioxidants may represent a major modifiable risk factor for disease progression. This study aims to identify key predictors of serum antioxidant levels in patients with HCV, to examine the relationship between retinoid/carotenoid concentrations in serum and hepatic tissue, to quantify the association between systemic measures of oxidative stress and antioxidant status, and to examine the relationship between retinoids and stellate cell activation. METHODS: Patients undergoing liver biopsy (n = 69) provided fasting blood, fresh tissue, urine and completed a diet history questionnaire. Serum and questionnaire data from healthy volunteers (n = 11), normal liver tissue from public repositories and patients without liver disease (n = 11) were also collected. Urinary isoprostanes, serum and tissue retinoid concentrations were obtained by UHPLC-MS-MS. Immunohistochemistry for αSMA was performed on FFPE sections and subsequently quantified via digital image analysis. Associations between urinary isoprostanes, αSMA levels, and retinoids were assessed using Spearman correlation coefficients and non-parametric tests were utilized to test differences among disease severity groups. RESULTS: There was a significant inverse association between serum retinol, lycopene, and RBP4 concentrations with fibrosis stage. Serum ß-carotene and lycopene were strongly associated with their respective tissue concentrations. There was a weak downward trend of tissue retinyl palmitate with increasing fibrosis stage. Tissue retinyl palmitate was inversely and significantly correlated with hepatic αSMA expression, a marker for hepatic stellate cell activation (r = -0.31, P < 0.02). Urinary isoprostanes levels were inversely correlated with serum retinol, ß-carotene, and RBP4. CONCLUSIONS: A decrease in serum retinol, ß-carotene, and RBP4 is associated with early stage HCV. Retinoid and carotenoid levels decline as disease progresses, and our data suggest that this decline occurs early in the disease process, even before fibrosis is apparent. Measures of oxidative stress are associated with fibrosis stage and concurrent antioxidant depletion. Vitamin A loss is accompanied by stellate cell activation in hepatic tissue.

Interferon-free regimens containing setrobuvir for patients with genotype 1 chronic hepatitis C: a randomized, multicenter study.

BACKGROUND & AIMS: Setrobuvir is a direct-acting antiviral (DAA) non-nucleoside inhibitor of hepatitis C virus (HCV) polymerase. This study examined interferon-free combinations containing setrobuvir, a ritonavir-boosted protease inhibitor (danoprevir/r) and ribavirin, with/without the nucleoside inhibitor mericitabine in HCV genotype (G)1 patients. METHODS: Non-cirrhotic treatment-naïve patients (N = 110) were randomized to five groups. Three groups received a 14-day mericitabine/ribavirin lead-in followed by treatment with 3 DAAs (setrobuvir, danoprevir/r, mericitabine) plus ribavirin for 12 weeks (Group A: G1a; D: G1b) or 24 weeks (B: G1a), and two groups received 2 DAAs (setrobuvir, danoprevir/r) plus ribavirin for 12 weeks (E: G1b) or 24 weeks (C: G1a). Efficacy was defined as sustained virological response (HCV RNA <25 IU/ml after 12 weeks' follow-up, SVR12). RESULTS: Two groups met predefined futility criteria for breakthrough (C) or relapse (A) and were discontinued. SVR12 rates were 42.9% (3/7) and 74.1% (20/27) in G1a patients in Groups A and B, respectively, and 95.7% (22/23) and 68.2% (15/22) in G1b patients in Groups D and E respectively. All G1a patients assigned to 24 weeks of treatment who experienced a decrease in HCV RNA of ≥2.3 log10 IU by the end of the lead-in period (n = 28) achieved SVR12. Overall, treatment was well tolerated and most adverse events were mild to moderate. No major safety signals were identified. CONCLUSIONS: An interferon-free setrobuvir-based regimen (3 DAAs plus ribavirin) is safe and effective in treatment-naïve G1 patients.

Daclatasvir plus asunaprevir for HCV genotype 1b infection in patients with or without compensated cirrhosis: a pooled analysis.

BACKGROUND & AIMS: We compared outcomes by cirrhosis status across studies of the all-oral combination of daclatasvir (DCV) plus asunaprevir (ASV). METHODS: Outcomes from global and Japanese phase 2 and 3 clinical studies of DCV+ASV in patients with genotype (GT) 1b infection were assessed by cirrhosis status. Sustained virological response (SVR) was assessed in individual phase 3 studies; a pooled analysis was carried out for safety outcomes. RESULTS: In the Japanese phase 3 study, SVR12 was achieved by 91% of patients with cirrhosis (n = 22) and 84% of patients without cirrhosis (n = 200); in the global phase 3 study, SVR12 was achieved by 84% of patients with cirrhosis (n = 206) and by 85% of patients without cirrhosis (n = 437). The frequency of serious adverse events, adverse events leading to treatment discontinuation and treatment-emergent grade 3/4 laboratory abnormalities was low (<10%) and similar among patients with (n = 229) or without (n = 689) compensated cirrhosis receiving DCV+ASV. Grade 3/4 reductions in platelets and neutrophils were more common among patients with cirrhosis (1.3 and 2.2%, respectively) compared with those without cirrhosis (both 0.6%). Grade 3/4 liver function test abnormalities were less common among patients with cirrhosis (1.8%) compared with those without cirrhosis (3.5-4.7%). Alanine aminotransferase elevations were not associated with hepatic decompensation. CONCLUSIONS: The safety and efficacy of DCV+ASV were similar in patients with or without compensated cirrhosis. This all-oral, interferon- and ribavirin-free combination is an effective and well-tolerated treatment option for patients with HCV GT1b infection and cirrhosis. Trial registrations numbers: Clinicaltrials.gov identifiers: NCT01012895; NCT01051414; NCT01581203; NCT01497834.

The benefit of paracentesis on hospitalized adults with cirrhosis and ascites.

BACKGROUND AND AIM: The aim of this study is to assess paracentesis utilization and outcomes in hospitalized adults with cirrhosis and ascites. METHODS: The 2011 Nationwide Inpatient Sample was used to identify adults, non-electively admitted with diagnoses of cirrhosis and ascites. The primary endpoint was in-hospital mortality. Variables included patient and hospital demographics, early (Day 0 or 1) or late (Day 2 or later) paracentesis, hepatic decompensation, and spontaneous bacterial peritonitis. RESULTS: Out of 8 023 590 admissions, 31 614 met inclusion criteria. Among these hospitalizations, approximately 51% (16 133) underwent paracentesis. The overall in-hospital mortality rate was 7.6%. There was a significantly increased mortality among patients who did not undergo paracentesis (8.9% vs 6.3%, P < 0.001). Patients who did not receive paracentesis died 1.83 times more often in the hospital than those patients who did receive paracentesis (95% confidence interval 1.66-2.02). Patients undergoing early paracentesis showed a trend towards reduction in mortality (5.5% vs 7.5%) compared with those undergoing late paracentesis. Patients admitted on a weekend demonstrated less frequent use of early paracentesis (50% weekend vs 62% weekday) and demonstrated increased mortality (adjusted odds ratio 1.12 95% confidence interval 1.01-1.25). Among patients diagnosed with spontaneous bacterial peritonitis, early paracentesis was associated with shorter length of stay (7.55 vs 11.45 days, P < 0.001) and decreased hospitalization cost ($61 624 vs $107 484, P < 0.001). CONCLUSION: Paracentesis is under-utilized among cirrhotic patients presenting with ascites and is associated with decreased in-hospital mortality. These data support the use of paracentesis as a key inpatient quality measure among hospitalized adults with cirrhosis. Future studies are needed to investigate the barriers to paracentesis use on admission.

Discovery of a Novel Human Pegivirus in Blood Associated with Hepatitis C Virus Co-Infection.

Hepatitis C virus (HCV) and human pegivirus (HPgV), formerly GBV-C, are the only known human viruses in the Hepacivirus and Pegivirus genera, respectively, of the family Flaviviridae. We present the discovery of a second pegivirus, provisionally designated human pegivirus 2 (HPgV-2), by next-generation sequencing of plasma from an HCV-infected patient with multiple bloodborne exposures who died from sepsis of unknown etiology. HPgV-2 is highly divergent, situated on a deep phylogenetic branch in a clade that includes rodent and bat pegiviruses, with which it shares <32% amino acid identity. Molecular and serological tools were developed and validated for high-throughput screening of plasma samples, and a panel of 3 independent serological markers strongly correlated antibody responses with viral RNA positivity (99.9% negative predictive value). Discovery of 11 additional RNA-positive samples from a total of 2440 screened (0.45%) revealed 93-94% nucleotide identity between HPgV-2 strains. All 12 HPgV-2 RNA-positive cases were identified in individuals also testing positive for HCV RNA (12 of 983; 1.22%), including 2 samples co-infected with HIV, but HPgV-2 RNA was not detected in non-HCV-infected individuals (p<0.0001), including those singly infected by HIV (p = 0.0075) or HBV (p = 0.0077), nor in volunteer blood donors (p = 0.0082). Nine of the 12 (75%) HPgV-2 RNA positive samples were reactive for antibodies to viral serologic markers, whereas only 28 of 2,429 (1.15%) HPgV-2 RNA negative samples were seropositive. Longitudinal sampling in two individuals revealed that active HPgV-2 infection can persist in blood for at least 7 weeks, despite the presence of virus-specific antibodies. One individual harboring both HPgV-2 and HCV RNA was found to be seronegative for both viruses, suggesting a high likelihood of simultaneous acquisition of HCV and HPgV-2 infection from an acute co-transmission event. Taken together, our results indicate that HPgV-2 is a novel bloodborne infectious virus of humans and likely transmitted via the parenteral route.

Screening for Zinc Deficiency in Patients with Cirrhosis: When Should We Start?

BACKGROUND: Zinc deficiency has been observed in cirrhosis, but management guidelines do not address screening for zinc deficiency. We aim to determine the prevalence of zinc deficiency in different stages of cirrhosis and to correlate zinc levels with complications of cirrhosis and clinical outcomes. Patients who had a diagnosis of cirrhosis and had serum zinc levels drawn from 2007 to 2011 were identified. Demographics, laboratory data, presence of ascites, encephalopathy, and infection were obtained; Child-Pugh and MELD scores were calculated. Stata software was used for data analysis. A total of 163 patients were included in the study. RESULTS: The median serum zinc level was 0.47 mcg/ml (IQR 0.37-0.63); 83 % of patients were zinc deficient. Zinc deficiency was more prevalent in patients with Child-Pugh score B or C, and with MELD scores ≥15. Zinc levels were lower in alcoholic, hepatitis C, and cholestatic diseases than in other etiologies of liver disease. Zinc levels correlated with INR (r = -0.56, p < 0.001), bilirubin (r = -0.51, p < 0.001), and albumin (r = 0.68, p < 0.001), and were lower in patients with ascites (0.40 vs. 0.57 mcg/ml, p < 0.001), encephalopathy (0.40 vs. 0.53 mcg/ml, p < 0.001), diuretic use (0.45 vs. 0.535 mcg/ml, p = 0.005), and infection (0.32 vs. 0.51 mcg/ml, p < 0.001). Ascites (p = 0.044) and infection (p = 0.009) were independently associated with zinc levels. Zinc-deficient patients had lower transplant-free survival rates than non-deficient patients. CONCLUSION: Zinc deficiency is highly prevalent in cirrhotic patients with Child-Pugh score B or C, and with MELD score ≥15. Zinc deficiency also correlates with disease severity, infection, and a worse transplant-free survival. Screening for zinc deficiency should be considered in this subset of patients.

Daclatasvir and asunaprevir plus peginterferon alfa and ribavirin in HCV genotype 1 or 4 non-responders.

BACKGROUND & AIMS: Improved therapies for peginterferon/ribavirin null or partial responders are needed. This study evaluated daclatasvir (NS5A inhibitor) and asunaprevir (NS3 protease inhibitor) plus peginterferon alfa-2a and ribavirin in this patient population. METHODS: This open-label, phase 3 study (HALLMARK-QUAD; NCT01573351) treated patients with chronic hepatitis C virus (HCV) genotype 1 (n=354) or 4 (n=44) infection who had a prior null or partial response to peginterferon/ribavirin. Patients received daclatasvir 60 mg once-daily plus asunaprevir 100mg twice-daily, with weekly peginterferon alfa-2a and weight-based ribavirin for 24 weeks. The primary endpoint was sustained virological response at post-treatment week 12 (SVR12) among genotype 1-infected patients. RESULTS: Daclatasvir plus asunaprevir and peginterferon/ribavirin demonstrated SVR12 rates of 93% (95% CI 90-96) in prior non-responders infected with HCV genotype 1. SVR12 rates among genotype 4-infected patients were 98% (95% CI 93-100); one patient had a missing post-treatment week-12 HCV-RNA measurement, but achieved an SVR at post-treatment week 24, yielding a 100% SVR rate in genotype 4 patients. Prior peginterferon/ribavirin response, sex, age, IL28B genotype, or cirrhosis status did not influence SVR12 rates. Serious adverse events occurred in 6% of patients; 5% discontinued treatment due to an adverse event. Grade 3/4 laboratory abnormalities included neutropenia (22%), lymphopenia (16%), anemia (6%), thrombocytopenia (4%), and ALT/AST elevations (3% each). CONCLUSIONS: Daclatasvir plus asunaprevir and peginterferon/ribavirin demonstrated high rates of SVR12 in genotype 1- or 4-infected prior null or partial responders. The combination was well tolerated and no additional safety and tolerability concerns were observed compared with peginterferon/ribavirin regimens.

Randomized study of danoprevir/ritonavir-based therapy for HCV genotype 1 patients with prior partial or null responses to peginterferon/ribavirin.

BACKGROUND & AIMS: Chronic hepatitis C treatment for prior non-responders to peginterferon (PegIFN)/ribavirin remains suboptimal. The MATTERHORN study evaluated regimens containing ritonavir-boosted danoprevir (danoprevir/r) in prior PegIFN alfa/ribavirin non-responders. METHODS: Prior partial responders (N=152) were randomized to 24 weeks of twice-daily danoprevir/r 100/100mg, mericitabine 1000 mg and ribavirin 1000/1200 mg (IFN-free); danoprevir/r plus PegIFN alfa-2a/ribavirin (triple); or danoprevir/r, mericitabine and PegIFN alfa-2a/ribavirin (Quad). Prior null responders (N=229) were randomized to 24 weeks of IFN-free therapy, or quad alone (Quad 24) or quad plus 24-weeks of PegIFN alfa-2a/ribavirin (Quad 48). The primary endpoint was sustained virological response (HCV RNA <25 IU/ml) 24 weeks after end-of-treatment (SVR24). Due to high relapse rates, genotype (G) 1a patients in IFN-free arms were offered additional PegIFN alfa-2a/ribavirin. RESULTS: Among prior partial responders, SVR24 rates were 46.2%, 51.0%, and 86.0%, in the IFN-free, Triple and Quad arms, respectively; among prior null responders, SVR24 rates were 45.5%, 80.5%, and 83.8% respectively. Relapse rates were lower and SVR24 rates higher in G1b-infected than G1a-infected patients. SVR24 rates in G1a and G1b patients randomized to Quad were 75.0% and 96.2%, respectively, in the partial Quad arm, and 68.1% and 100%, respectively, in the null Quad 24 arm. Treatment failure was associated with resistance to danoprevir, but not to mericitabine, and was more common in G1a infected patients. Treatment was well-tolerated. CONCLUSIONS: Danoprevir/r, mericitabine plus PegIFN alfa-2a/ribavirin was well-tolerated and produced high overall SVR24 rates in prior partial and null responders to PegIFN alfa/ribavirin. In contrast, IFN-free regimens were associated with unacceptably high relapse rates.

Pegylated interferon based therapy with second-wave direct-acting antivirals in genotype 1 chronic hepatitis C.

Within the last few years, treatment of chronic hepatitis C infection has progressed beyond regimens containing the first-wave direct-acting antiviral agents (DAAs) boceprevir and telaprevir, which had high pill burdens as well as low efficacy and safety in treatment-experienced patients. Triple therapy regimens with newer second-wave DAAs combined with pegylated interferon (PEG-IFN) and ribavirin (RBV), have shown rates of sustained virological response never before achieved with previous regimens in treatment-naïve genotype 1 (HCV-1) patients. Additionally, increased response rates have been found with quadruple agent therapy in prior non-responders, partial-responders, and relapsers, including those with cirrhosis. This review will focus on the second-wave DAAs including protease inhibitors (PI), nucleotide inhibitors, and NS5B inhibitors combined with PEG-IFN and RBV for both treatment-naïve and treatment-experienced genotype 1 hepatitis C virus (HCV-1) infected patients. The current standard of care for treatment-naïve HCV-1 is the second-wave PI, sofosbuvir, plus PEG-IFN/RBV and sofosbuvir plus the second-wave nucleotide inhibitor simeprevir with or without RBV in treatment-experienced HCV-1 patients. These recommendations could change, especially for treatment-experienced patients based on the positive results obtained with the newest quadruple therapy studies.

Human immunodeficiency virus and coinfection with hepatitis B and C.

In HIV-infected individuals, coinfection with HBV and/or HCV is common because of shared modes of transmission. It is known that HIV accelerates progression of liver disease and results in increased morbidity and mortality associated with viral hepatitis, but it is less clear if viral hepatitis has a direct effect on HIV. Treatment of viral hepatitis improves outcomes and should be considered in all HIV-infected patients. Treatment of HBV without concurrent treatment of HIV is risky because resistance can occur in both viruses if regimens are not carefully chosen.

Interferon-combination strategies for the treatment of chronic hepatitis C.

Direct acting antiviral agents have revolutionized hepatitis C (HCV) therapy. Many agents that are either currently available or undergoing investigation offer higher rates of sustained virologic response, reduced toxicity and shorter duration of therapy when compared to traditional treatment consisting of pegylated interferon and ribavirin. Although interferon free therapy may be a preferred option, some patients may still require an interferon based regimen to ensure efficacy. In this review, we discuss therapeutic strategies which utilize various combinations of protease inhibitors, NS5A inhibitors, nucleotide polymerase inhibitors and non-nucleoside polymerase inhibitors along with pegylated interferon in the treatment of chronic HCV.