Novel treatments for chronic hepatitis C: closing the remaining gaps

Analysis of Patients' Characteristics and Treatment Profile of People Who Use Drugs (PWUDs) with and without a Co-Diagnosis of Viral Hepatitis C: A Real-World Retrospective Italian Analysis

PURPOSE

Hepatitis C virus (HCV) spreads from contact with blood of an infected person. HCV infections are common among people who use drugs (PWUDs), when sharing needles, syringes, or other equipment for injected drugs. The advent of pangenotypic direct-antiviral agents (DAA) in 2017 transformed the treatment landscape for HCV, but PWUDs remain a complex and hard-to-treat population with high risk of HCV reinfection. The aim of this real-world analysis was to characterize the demographic and clinical features of PWUDs in Italy, also focusing on comorbidity profile, treatment with DAAs, resource consumptions for the National Health System (NHS).

PATIENTS AND METHODS

During 01/2011-06/2020, administrative databases of Italian healthcare entities, covering 3,900,000 individuals, were browsed to identify PWUDs with or without HCV infection. Among HCV+ patients, a further stratification was made into treated and untreated with DAAs. The date of PWUD or HCV first diagnosis or DAA first prescription was considered as index-date. Patients were then followed-up for one year. Alcohol-dependency was also investigated.

RESULTS

Total 3690 PWUDs were included, of whom 1141 (30.9%) PWUD-HCV+ and 2549 (69.1%) PWUD-HCV-. HCV-positive were significantly older (43.6 vs 38.5 years, p < 0.001), had a worse comorbidity profile (Charlson-index: 0.8 vs 0.4, p < 0.001), and high rates of psychiatric, respiratory, dermatological, musculoskeletal diseases and genitourinary (sexually transmitted) infections. Moreover, they received more drug prescriptions (other than DAAs, like anti-acids, antiepileptics, psycholeptics) and had undergone more frequent hospitalization, predominantly for hepatobiliary, respiratory system and mental disorders. DDA-untreated had significantly higher Charlson-index than DAA-treated (0.9 vs 0.6, p = 0.003). Alcoholism was found in 436 (11.8%) cases.

CONCLUSION

This Italian real-world analysis suggests that PWUDs with HCV infection, especially those untreated with DAAs, show an elevated drug consumption due to their complex clinical profile. These findings could help to ameliorate the healthcare interventions on PWUDs with HCV infection.

Screening at a Federally Qualified Health Center in the Midwest for Hepatitis C Among People Who Inject Drugs, 2019-2020

Introduction

Hepatitis C virus (HCV) infection is a public health epidemic. People who inject drugs (PWID) are at high risk for transmitting and contracting HCV. The objective of this study was to assess the effectiveness of a multifaceted intervention at a federally qualified health center in the US Midwest to improve HCV screening rates among PWID.

Methods

A prospective quality improvement initiative was conducted to increase the proportion of PWID screened for HCV. Inclusion criteria consisted of being seen by a primary care provider from April 16, 2019, through February 28, 2020, being aged 18 years or older, and confirmation of intravenous drug use. PWID status was confirmed by reviewing electronic health records. The multifaceted intervention consisted of educational sessions for the health care team and workflow changes. We analyzed the proportion of patients screened preintervention and postintervention by using χ² tests.

Results

Of 742 patients who met the inclusion criteria, the proportion of PWID screened preintervention was 59.6% (n = 329) and the proportion of PWID screened postintervention was 65.1% (n = 283), increasing the screening rate by 5.5 percentage points. A χ² test of homogeneity indicated a significant relationship between the preintervention and postintervention periods, and screening outcomes (P < .001).

Conclusion

This multifaceted intervention to increase HCV screening resulted in a modest increase in the proportion of PWID screened. Consistent and health care system–wide screening approaches are needed to optimize the potential of HCV treatment and cure options now available.

Natural Killer Cells and T Cells in Hepatocellular Carcinoma and Viral Hepatitis: Current Status and Perspectives for Future Immunotherapeutic Approaches

Natural killer (NK) cells account for 25–50% of the total number of hepatic lymphocytes, which implicates that NK cells play an important role in liver immunity. The frequencies of both circulating and tumor infiltrating NK cells are positively correlated with survival benefit in hepatocellular cancer (HCC) and have prognostic implications, which suggests that functional impairment in NK cells and HCC progression are strongly associated. In HCC, T cell exhaustion is accompanied by the interaction between immune checkpoint ligands and their receptors on tumor cells and antigen presenting cells (APC). Immune checkpoint inhibitors (ICIs) have been shown to interfere with this interaction and have altered the therapeutic landscape of multiple cancer types including HCC. Immunotherapy with check-point inhibitors, aimed at rescuing T-cells from exhaustion, has been applied as first-line therapy for HCC. NK cells are the first line effectors in viral hepatitis and play an important role by directly eliminating virus infected cells or by activating antigen specific T cells through IFN-γ production. Furthermore, chimeric antigen receptor (CAR)-engineered NK cells and T cells offer unique opportunities to create CAR-NK with multiple specificities learning from the experience gained with CAR-T cells with potentially less adverse effects. This review focus on the abnormalities of NK cells, T cells, and their functional impairment in patients with chronic viral hepatitis, which contributes to progression to hepatic malignancy. Furthermore, we discuss and summarize recent advances in the NK cell and T cell based immunotherapeutic approaches in HCC.

Hepatitis C virus-related cryoglobulinemic vasculitis

INTRODUCTION

Hepatitis C virus (HCV) infection affects about 170 million people worldwide. HCV is responsible for both hepatitis and extra-hepatic manifestations. Chronic infection has been shown to develop in about 70% of cases, and it can progress to cirrhosis or hepatocellular carcinoma. Ten percent of HCV patients may develop extra-hepatic manifestations, including mixed cryoglobulinemia (MC) and non-Hodgkin lymphomas (NHL). Cryoglobulinemic vasculitis (CV) varies, ranging from mild-moderate clinical symptoms (purpura on the legs, asthenia and arthralgias) and chronic hepatitis to severe symptoms (ulcers on the legs, peripheral neuropathy, glomerulonephritis, low-grade NHL to life threatening complications (rapid progressive glomerulonephritis, gastrointestinal vasculitis, acute hyper-viscosity).

EVIDENCE ACQUISITION

CV is associated with significant morbidity and mortality. Some studies have shown kidney involvement, cirrhosis, central nervous system involvement, and heart involvement as unfavorable prognostic factors. Many studies have demonstrated that, after antiviral therapy, CV can disappear along with HCV. After the introduction of the new direct antiviral agents (DAAs), the combination of pegylated interferon and ribavirin has been abandoned.

EVIDENCE SYNTHESIS

Several studies on new DAAs have reported remarkable 90% to 100% HCV eradication rates, regardless of genotype. Treatment with DAAs has comparable efficacy on viral eradication in CV patients but definite clinical improvements of vasculitis can be observed only in half the patients.

CONCLUSIONS

In patients with mild to moderate CV disease, DAAs therapy should be used as first line approach. In patients with severe vasculitis, DAAs therapy and a second-line treatment with RTX with or without aphaeresis are a required.

A proof-of-concept study in HCV-infected Huh7.5 cells for shortening the duration of DAA-based triple treatment regimens

With the development of more effective direct-acting antivirals (DAAs), dual- or triple-therapy regimens represent the major strategy used to cure chronic hepatitis C virus (HCV) infection. Thus, shorter treatment duration regimens with low burden, few adverse effects and good patient adherence are urgently needed. This study theoretically demonstrates a proof-of-concept approach for shortening therapy duration by examining HCV-infected Huh7.5 cells after treatment with a high or low fixed dose of three DAAs (simeprevir + daclatasvir + sofosbuvir) for 6-15 days. The results demonstrated that HCV-infected Huh7.5 cells achieved an ultrarapid virologic response with undetectable HCV RNA and protein and were cured after treatment with the triple-therapy regimen for 15 days. When the treatment duration was shortened, virologic relapse might occur after treatment with a low fixed dose of the three DAAs for 9 days and did occur after treatment with a low fixed dose for 6 days, although HCV was below detectable levels at the end of treatment. However, virologic relapse could be avoided with treatment of a high fixed dose of the three DAAs for 9 or 6 days. Although a virologic breakthrough occurred after an intermittent treatment regimen at the low fixed dose, the high fixed dose cured HCV-positive Huh7.5 cells with intermittent treatment. In conclusion, HCV is persistently present below detectable levels in HCV-infected Huh7.5 cells for a long time after treatment, and a shortened therapy duration is associated with an increased risk of virologic relapse, but virologic relapse or breakthrough might be avoided by treatment with a combination of more highly effective DAAs.

Efficacy and safety of alisporivir for the treatment of hepatitis C infection

Alisporivir (ALV) (previously known as Debio 025) is a potent, pangenotypic host-targeting antiviral oral agent acting on cyclophilin A, which is necessary for HCV replication. Areas covered: This article reviews the therapeutic efficacy and safety of ALV for the treatment of HCV infection. Expert opinion: Direct-acting antivirals (DAAs) have revolutionized the HCV antiviral treatment paradigm with success rates well above 95% for all HCV genotypes. However, challenges still remain in certain patient populations such as those who have developed resistance and have experienced multi-DAA failure. To cure HCV infection, a treatment regimen must combine antiviral potency and a high barrier to resistance. ALV fulfills this need as shown by the studies evaluating its clinical efficacy. Nevertheless, ALV missed the chance to be included in the HCV treatment armamentarium after the FDA halted clinical studies following reports of serious side effects (three cases of pancreatitis, one lethal). However, it is possible that ALV could still be considered for HCV-infected non-cirrhotic patients that are infected with a multiresistant virus or with HCV genotype 3, although it must be said that the drug industry would be reluctant to invest in new antivirals if the current clinical need is effectively met.

Outcomes and costs of treating hepatitis C patients with second-generation direct-acting antivirals: results from the German Hepatitis C-Registry

OBJECTIVE

Chronic hepatitis C virus infection is associated with a significant health burden. Long-term consequences are the development of liver cirrhosis and hepatocellular carcinoma. The introduction of direct-acting antivirals (DAA) has led to an increase in sustained virologic response rates (SVR), but is accompanied by higher treatment costs. The aim of this study was to assess the outcomes and costs of treating hepatitis C virus infected patients with DAAs in clinical practice in Germany.

PATIENTS AND METHODS

Data were derived from a noninterventional study including a pharmacoeconomic subset of 2673 patients with genotypes 1 and 3 who initiated and completed treatment between February 2014 and February 2017. Sociodemographic and clinical parameters as well as resource utilization were collected using a web-based data recording system. Costs were calculated using official remuneration schemes.

RESULTS

The mean age of the patients was 54.6 years; 48% were men. 93.5% of all patients achieved an SVR. The average total treatment costs were &OV0556;67 979 (&OV0556;67 131 medication costs, &OV0556;824 ambulatory care, &OV0556;24 hospital costs). The average costs per SVR of &OV0556;72 705 were calculated. Differences in SVR and costs according to genotype, treatment regimen, treatment experience, and cirrhosis were observed. Quality-of-life data showed no or a minimal decrease during treatment.

CONCLUSION

This analysis confirms high SVR rates for newly introduced DAAs in a real-world setting. Costs per SVR estimated are comparable to first-generation DAA. Given the fact that the costs for the currently used treatment regimens have declined, it can be assumed that the costs per SVR have also decreased. Our insight into real-world outcomes and costs can serve as a basis for a comparison with the mentioned newly introduced treatment regimens.

A pan-genotypic Hepatitis C Virus NS5A amplification method for reliable genotyping and resistance testing

BACKGROUND

Chronic infection with the Hepatitis C Virus (HCV) is associated with the risk of progressive liver disease. Although, HCV treatment options and viral cure rates have tremendously increased over the last decade, all currently licensed combination therapies contain inhibitors of the replication complex NS5A. Resistance-associated substitutions (RAS) in NS5A can limit the efficacy of therapy; however, resistance testing is routinely not recommended for all patients. Notably, pan-genotypic combinations have been approved, however the correct identification of the HCV genotype is still required for treatment decisions and is a good predictor for treatment success.

OBJECTIVE

The aim of this study was the establishment of a pan-genotypic NS5A amplification method for reliable genotyping and simultaneous resistance testing in a fast and cheap routine diagnostic setup.

STUDY DESIGN

Pan-genotypic degenerated nested PCR primer were designed and tested in 262 HCV-patients. The collection included samples from genotypes 1-7 and the median viral load was 1.07 × 10⁶ IU/ml (range 248-21 × 10⁶ IU/ml).

RESULTS

Amplification of the expected 747bp fragment was successful in 257 of 262 (98.1%) samples including samples <1000 IU/ml. The direct comparison of the genotype information obtained with core sequencing to those obtained by NS5A prediction showed high concordance (97.3%) and discrepancies occurred only for relatively rare subtypes. Resistance analysis using Geno2Pheno_[HCV] showed NS5A-RAS in 23 of 257 (8.9%) of samples.

CONCLUSIONS

We successfully developed a routine diagnostic method for pan-genotypic amplification of NS5A. This amplicon can be used for simultaneous genotyping and resistance testing for enhancing and improving routine HCV diagnostic.

Further characterization of bovine hepacivirus: Antibody response, course of infection, and host tropism

Bovine hepacivirus (BovHepV) is a recently added member to the growing genus Hepacivirus within the family Flaviviridae. Animal hepaciviruses are rarely characterized so far. Apart from norway rat hepacivirus which represents a promising HCV surrogate model, only equine hepaciviruses have been studied to some extent. BovHepV has been initially identified in bovine samples and was shown to establish persistent infections in cattle. However, consequences of those chronic infections, humoral immune response and the possibility of an extended host spectrum have not been explored so far. Therefore, we here investigated (a) the presence of anti-NS3-antibodies and viral RNA in cattle herds in Germany, (b) the course of infection in cattle, and (c) the host tropism including zoonotic potential of bovine hepaciviruses. Our results show that 19.9% of investigated bovine serum samples had antibodies against BovHepV. In 8.2% of investigated samples, viral RNA was detected. Subsequent genetic analysis revealed a novel genetic cluster of BovHepV variants. For 25 selected cattle in a BovHepV positive herd the presence of viral genomic RNA was monitored over one year in two to three months intervals by RT-PCR in order to discriminate acute versus persistent infection. In persistently infected animals, no serum antibodies were detected. Biochemical analyses could not establish a link between BovHepV infection and liver injury. Apart from a single sample of a pig providing a positive reaction in the antibody test, neither BovHepV-specific antibodies nor viral RNA were detected in porcine, equine or human samples implying a strict host specificity of BovHepV.

Safety and efficacy of elbasvir/grazoprevir for the treatment of chronic hepatitis C: current evidence

Treatments for hepatitis C virus (HCV) have advanced greatly, becoming more efficacious with fewer adverse events, due to the availability of direct-acting antiviral agents, which target specific steps in the HCV life cycle. Recently, a combination regimen consisting of the HCV nonstructural protein 5A inhibitor elbasvir (EBR) and the HCV NS3/4A protease inhibitor grazoprevir (GZR) was approved for the treatment of patients with chronic HCV and genotypes (Gts) 1 and 4 in various countries. In Phase III trials, the combination of EBR/GZR (fixed-dose combination table or single agent) for 12 or 16 weeks of treatment with or without ribavirin resulted in a high sustained virological response at 12 weeks in treatment-naïve and treatment-experienced patients with HCV Gt 1a, 1b, 4, or 6, including special populations, such as individuals with advanced chronic kidney disease, HCV-HIV coinfection, and compensated cirrhosis. In this review, we focus on the mode of action, pharmacokinetics, clinical applications, efficacy, and safety profile of EBR/GZR, including special populations who have been considered refractory from the extensive evidence of clinical trials.

Natural Killer Cells in Liver Disease and Hepatocellular Carcinoma and the NK Cell-Based Immunotherapy

Nature killer (NK) cells play a critical role in host innate and adaptive immune defense against viral infections and tumors. NK cells are enriched in liver hematopoietic cells with unique NK repertories and functions to safeguard liver cells against hepatitis virus infection or malignancy transformation. However, accumulating evidences were found that the NK cells were modulated by liver diseases and liver cancers including hepatocellular carcinoma (HCC) and showed impaired functions failing to activate the elimination of the viral-infected cells or tumor cells and were further involved in the pathogenesis of liver injury and inflammation. The full characterization of circulation and intrahepatic NK cell phenotype and function in liver disease and liver cancer has not only provided new insight into the disease pathogenesis but has also discovered new targets for developing new NK cell-based therapeutic strategies. This review will discuss and summarize the NK cell phenotypic and functional changes in liver disease and HCC, and the NK cell-based immunotherapy approaches and progresses for cancers including HCC will also be reviewed.

Development of a Comprehensive Dataset of Hepatitis C Patients and Examination of Disease Epidemiology in the United States, 2013-2016

INTRODUCTION

Chronic infection with hepatitis C virus (HCV) is a leading cause of liver disease and infectious disease deaths. While recent and emerging treatment options for HCV patients have enabled higher rates of sustained virologic response (SVR), the demographic, clinical, geographic, and payer characteristics of the estimated 3.4 million chronic HCV patients in the USA are poorly understood. The goal of this study was to create a dataset describing the current HCV patient landscape in the USA.

METHODS

Data from two large national laboratory companies representing the majority of US patients screened for HCV antibody and/or tested for HCV RNA from 2013 through 2016 were organized into the present study dataset. Age, gender, payer channel, 3-digit ZIP code and ordering physician specialty, and 3-digit ZIP code information were available for all patients. Among RNA-positive patients, additional clinical characteristics included HCV genotype, fibrosis stage, renal function, and HIV status. Initiating treatment and attaining cure were imputed using data-driven algorithms based on successive RNA viral load measurements.

RESULTS

The number of RNA-positive HCV patients increased from 200,066 patients in 2013 to 469,550 in 2016. The availability of clinical data measurements and rates of treatment initiation increased over the study period, indicating improved care engagement for HCV patients. Treatment and cure rates varied by age, disease severity, geographic location, and payer channel. Sensitivity and specificity of the cure prediction algorithms were consistently above 0.90, validating the robustness of the data imputation approach.

CONCLUSION

This is the largest, most comprehensive dataset available to describe the current US HCV patient landscape. Our results highlight that the epidemiology of HCV is evolving with an increasing number of patients who are younger and have milder disease than described in previous years. Results of this study should help guide efforts toward the elimination of HCV in this country. Future work will focus on factors associated with varying treatment and cure patterns and describing recent changes in the HCV patient landscape.

FUNDING

AbbVie. Plain language summary available for this article.

Pharmacokinetic and pharmacodynamic evaluation of daclatasvir, asunaprevir plus beclabuvir as a fixed-dose co-formulation for the treatment of hepatitis C

INTRODUCTION

Many reports have evaluated the clinical efficacy and safety of the fixed-dose all-oral combination of daclatasvir, asunaprevir, and beclabuvir (DCV-TRIO), which was approved in Japan in December 2016 for the treatment of hepatitis C genotype (GT)-1 infection. Areas covered: This article reviews the pharmacodynamic and pharmacokinetic properties of the DCV-TRIO combination. The topics covered include data regarding the drug's absorption, distribution, metabolism, excretion, and antiviral activity strategies. Its therapeutic efficacy and safety in GT-1 infection from phase 2/3 clinical trials are also discussed. Expert opinion: The ideal regimen for the treatment of Hepatitis C virus infection should be potent, pangenotypic, Ribavirin-free, safe, co-formulated, and affordable. Considering these characteristics, DCV-TRIO is neither pangenotypic nor potent enough against GT-1a, regardless of the presence or absence of cirrhosis. Other potential limitations of this regimen are its dosification (twice-daily), and the fact that since it includes a protease inhibitor, it is contraindicated in decompensated cirrhosis. For these reasons, it has only been approved in Japan, where more than 70% of the patients are infected with GT-1b. However, this co-formulation might still have a place in the treatment of non-cirrhotic patients infected with GT-1b provided that massive access to treatment is facilitated.

Crossing the Iron Gate: Why and How Transferrin Receptors Mediate Viral Entry

Because both the host and pathogen require iron, the innate immune response carefully orchestrates control over iron metabolism to limit its availability during times of infection. Nutritional iron deficiency can impair host immunity, while iron overload can cause oxidative stress to propagate harmful viral mutations. An emerging enigma is that many viruses use the primary gatekeeper of iron metabolism, the transferrin receptor, as a means to enter cells. Why and how this iron gate is a viral target for infection are the focus of this review.

Glecaprevir + pibrentasvir for treatment of hepatitis C

INTRODUCTION

Glecaprevir/pibrentasvir is a fixed-dose combination regimen of a new generation NS3/4A inhibitor and an NS5A inhibitor with potent antiviral activity against all hepatitis C virus (HCV) genotypes. This regimen offers a shorter course of therapy (8 weeks) for selected patients regardless of genotype and has demonstrated high virological efficacy for retreatment of individuals who previously failed an NS5A containing regimen. Glecaprevir and pibrentasvir are minimally excreted by the kidneys; thus this regimen can safely be used in individuals with severe chronic kidney disease (CKD), including those undergoing hemodialysis. Areas covered: This review covers the mechanism of action, pharmacokinetics, clinical applications, efficacy, and safety profile of glecaprevir/pibrentasvir. It also covers key phase 2 and 3 clinical trials that led to licensure of this regimen. Expert opinion: Glecaprevir/pibrentasvir is the latest antiviral regimen licensed in the United States for treatment of HCV infection. Although several other direct-acting antiviral agents (DAAs) are currently available, glecaprevir/pibrentasvir has some unique characteristics that expand treatment options for HCV infection, including patients with comorbidities such as advanced stage CKD or prior treatment failure to antiviral regimens containing other DAAs.

Effect of HCV Core Antigen and RNA Clearance during Therapy with Direct Acting Antivirals on Hepatic Stiffness Measured with Shear Wave Elastography in Patients with Chronic Viral Hepatitis C

To assess a combination of novel measures of therapeutic success in the treatment of chronic hepatitis C (CHC) infection, we evaluated liver stiffness (LS) with shear wave elastography and hepatitis C virus core antigen (HCVcAg) concentrations. We followed 34 patients during and after treatment with direct acting antivirals. All patients achieved a sustained virologic and serologic response and a significant increase of albumin levels. Decreases of alanine aminotransferase (ALT) activity and alpha-fetoprotein (AFP) level were observed during the treatment and follow-up period. A significant decrease in LS was observed between baseline, end of treatment (EOT), and at 24- and 96-week post-treatment follow-up. LS decline between EOT and 96-week follow-up (FU96) was observed in 79% of patients. Significant LS changes were seen in patients with advanced fibrosis, particularly in cirrhotics and in patients with ALT exceeding 100 IU/mL. There was a positive correlation between ALT activity and LS changes at the baseline versus FU96. A negative correlation was demonstrated between individual HCVcAg baseline concentrations and reduction of LS at the baseline versus FU96. In conclusion, we observed that LS significantly declined during and after antiviral treatment. It was accompanied by improvement in some liver function measures, and disappearance of both HCVcAg and HCV ribonucleic acid (HCV RNA).