Hepatitis C virus cures after direct acting antiviral-related drug-induced liver injury: Case report

Direct-acting antivirals sofosbuvir and daclatasvir attenuate carbon tetrachloride-induced liver fibrosis in mice

Background and aim

Advanced liver fibrosis is a major risk for developing hepatocellular carcinoma (HCC) in chronic hepatitis C virus (HCV) patients. Direct-acting antivirals (DAAs) which are used for treating HCV infection, produce more than 90% cure rate but do not seem to diminish the rate of occurrence or recurrence of HCC. This study aimed to investigate the effect of DAAs sofosbuvir (SOF) and daclatasvir (DAC) on carbon tetrachloride (CCl4)-induced fibrotic changes in mice.

Methods

Eighty adult male Swiss albino mice were randomly allocated into 8 groups (10 mice/group): normal control group, SOF group (receiving SOF 80 mg/kg body weight (BW), oral gavage, daily), DAC group (receiving DAC 30 mg/kg BW, oral gavage, daily), SOF + DAC group (receiving a combination of both, daily), CCl4 model group (receiving CCl4 2 mL/kg BW, intraperitoneal twice weekly) and three CCl4-intoxicated groups receiving either SOF or DAC or their combination. All CCl4 groups received CCl4 for 12 weeks followed by DAAs for another 12 weeks.

Results

CCl4-induced a significant elevation of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), and produced histopathological evidence of fibrosis and liver degeneration along with a significant increase (P ≤ 0.001) of the proliferation markers (proliferating cell nuclear antigen (PCNA) and Ki-67), hepatic stellate cells (HSCs) activation markers (alpha-smooth muscle actin (α-SMA) and glial fibrillary acidic protein (GFAP)), fibrosis marker (matrix metalloproteinase-9 (MMP-9)) and pro-inflammatory cytokine (tumor necrosis factor-alpha (TNF-α)). CCl4-intoxicated mice treated with SOF, DAC, or their combination revealed a significant amelioration (P ≤ 0.001) of CCl4-induced elevation of liver enzymes, fibrotic changes, and liver degeneration along with a significant attenuation (P ≤ 0.001) of CCl4-induced upregulation of all tested markers. The effects of SOF, DAC, and their combination on liver enzymes were comparable while the effect of SOF + DAC combination on mitigating CCl4-induced upregulation of the proliferation and HSCs activation markers was significantly stronger than either SOF or DAC alone. As for MMP-9 and TNF-α, the effects of DAC and SOF + DAC combination were comparable and both were more significant than that of SOF alone.

Conclusions

SOF and DAC may possess an antifibrotic effect that is independent of their role as antiviral agents against CCl4-induced liver injury. This might exclude the role of DAAs in early occurrence or accelerated recurrence of HCC through the progression of the HCV patients' pre-existing fibrosis. However, HCC patients treated with DAAs should be closely monitored with continuous HCC surveillance during and post-therapy.

Response guided therapy for reducing duration of direct acting antivirals in chronic hepatitis C infected patients: a Pilot study

The advent of direct-acting antivirals (DAAs) has transformed the landscape of hepatitis C virus (HCV) management. We aimed to prospectively (real-time) evaluate the feasibility of using a response-guided therapy approach, based on mathematical modeling of early viral kinetics, to reduce the duration of DAAs therapy. Patients were treated with DAAs according to the physicians' preference. HCV was measured at baseline and at day 2 and weeks 1, 2 and 4 after treatment initiation. The primary endpoint was the proportion of patients with sustained-virological response (SVR) at 12 and/or 24 weeks post-treatment. Twenty-nine patients (mean age 54 ± 16, 44% females, 73% with HCV genotype 1), were enrolled and all completed therapy. Treatment duration was shortened in 11 of the 29 patients (38%). SVR was achieved in 28 of the 29 patients (97%). Relapse occurred post treatment in a single case of a non-cirrhotic male with genotype 3, who was treated with sofosbuvir/velpatasvir for 6 weeks. Virus sequencing did not identify baseline or treatment emergent resistance associated substitutions. Real-time mathematical modeling of early HCV kinetics can be utilized for shortening DAAs duration in approximately 40% of patients without compromising treatment efficacy.Clinical trial registration: ClinicalTrials.gov Identifier: NCT03603327.

Analysis of Safety Outcomes in Chronic Hepatitis C Patients using Interferon-free Treatment: A Systematic Review of Case Reports

Background:

Second generation direct acting-antivirals are safe and effective treatments for chronic hepatitis C patients.

Objective:

We aimed to conduct a systematic review of case reports and case series to evaluate the safety of the drugs, highlighting a compilation of AE not previously reported in other reviews.

Methods:

The search was performed in four electronic databases and included only case reports and case series that evaluated interferon-free therapies and provided safety outcomes.

Results:

Initially 1,235 records were retrieved, and after screening 30 studies were included in the analysis (23 case reports and 7 case series). A total of 39 patients were included, receiving eight different interferon-free treatments. Nineteen patients discontinued treatment (only 8 of these achieved treatment response). Other 19 patients achieved SVR without discontinuation. Rare adverse events were observed, including breast hypertrophy, retinopathy and drug-induced infection. Some patients were in an advanced stage of the disease, and were therefore unable to withstand treatment due to the appearance of complications.

Conclusion:

In this sense, it is important to monitor the use of these drugs that can favor the appearance of serious AE. (PROSPERO registration number CRD42016051680).

Interferon at the cellular, individual, and population level in hepatitis C virus infection: Its role in the interferon-free treatment era

The advent of powerful direct-acting antiviral agents (DAAs) has revolutionized the treatment of hepatitis C. DAAs cure nearly all patients with short duration, oral treatments. Significant efforts are now underway to optimize DAA-based treatments. We discuss the potential role of interferon in this optimization. Clinical studies present compelling evidence that DAAs perform better in treatment-naive individuals than in individuals who previously failed treatment with interferon, a surprising correlation because interferon and DAAs are thought to act independently. Recent mathematical models explore a mechanistic hypothesis underlying this correlation. The hypothesis invokes the action of interferon at the cellular, individual, and population levels. Strong interferon responses prevent the productive infection of cells, reduce viral replication, and impede the development of resistance to DAAs in infected individuals and improve cure rates elicited by DAAs in treated populations. The models develop descriptions of these processes, integrate them into a comprehensive framework, and capture clinical data quantitatively, providing a successful test of the hypothesis. Individuals with strong endogenous interferon responses thus present a promising subpopulation for reducing DAA treatment durations. This review discusses the conceptual advances made by the models, highlights the new insights they unravel, and examines their applicability to optimize DAA-based treatments.

Interferon-Free Regimen: Equally Effective in Treatment Naive and Experienced HCV Patients

INTRODUCTION AND AIM

Interferon-free regimen has been reported to be highly efficient in treatment of HCV infection, including patients with compensated cirrhosis. We compared the efficacy of Ombitasvir, Paritaprevir, Ritonavir, Dasabuvir and Ribavirin (OBT/PTV/r, with DSV and RBV) therapy in patients with chronic HCV genotype 1b infection and compensated cirrhosis with and without prior treatment experience with pegylated interferon and ribavirin (IFN/RBV).

MATERIAL AND METHODS

A prospective two-center study was conducted in Mures County Hospital and Brasov County Hospital, Romania in period November 2015-July 2016. Both treatment naïve and PegIFN/RBV experienced patients with chronic HCV genotype 1b infection received 12 weeks of OBT/PTV/r, with DSV and RBV. Sustained virologic response 12 weeks after the treatment and eventual discontinuation of therapy due to adverse events were assessed in order to estimate safety and efficiency of therapeutic regimen.

RESULTS

Fifty nine patients were included in study, 35 (59.3%) of them were previously treated with IFN/RBV. Forty four (74.5%) patients were previously diag-nosed with cirrhosis Child Pugh score 5, while 15 (25.4%) with Child Pugh score 6. All 59 patients achieved a SVR12 of 100% and one patient from treatment naïve cohort discontinued the therapy due to hyperbilirubinemia and encephalopathy. However viral load assessed at 12 weeks after discontinuation of therapy in this patient was undetectable. Conclusion An all-oral regimen of co-for-mulated OBT/PTV/r with DSV and RBV results in high rate of sustained virologic response at post-treatment week 12 among HCV GT1b infected patients associated with compensated cirrhosis, regardless of previous treatment experience with PegIFN/RBV.

Modeling how reversal of immune exhaustion elicits cure of chronic hepatitis C after the end of treatment with direct-acting antiviral agents

A fraction of chronic hepatitis C patients treated with direct‐acting antivirals (DAAs) achieved sustained virological responses (SVR), or cure, despite having detectable viremia at the end of treatment (EOT). This observation, termed EOT⁺/SVR, remains puzzling and precludes rational optimization of treatment durations. One hypothesis to explain EOT⁺/SVR, the immunologic hypothesis, argues that the viral decline induced by DAAs during treatment reverses the exhaustion of cytotoxic T lymphocytes (CTLs), which then clear the infection after treatment. Whether the hypothesis is consistent with data of viral load changes in patients who experienced EOT⁺/SVR is unknown. Here, we constructed a mathematical model of viral kinetics incorporating the immunologic hypothesis and compared its predictions with patient data. We found the predictions to be in quantitative agreement with patient data. Using the model, we unraveled an underlying bistability that gives rise to EOT⁺/SVR and presents a new avenue to optimize treatment durations. Infected cells trigger both activation and exhaustion of CTLs. CTLs in turn kill infected cells. Due to these competing interactions, two stable steady states, chronic infection and viral clearance, emerge, separated by an unstable steady state with intermediate viremia. When treatment during chronic infection drives viremia sufficiently below the unstable state, spontaneous viral clearance results post‐treatment, marking EOT⁺/SVR. The duration to achieve this desired reduction in viremia defines the minimum treatment duration required for ensuring SVR, which our model can quantify. Estimating parameters defining the CTL response of individuals to HCV infection would enable the application of our model to personalize treatment durations.

A Robust and Efficient Numerical Method for RNA-Mediated Viral Dynamics

The multiscale model of hepatitis C virus (HCV) dynamics, which includes intracellular viral RNA (vRNA) replication, has been formulated in recent years in order to provide a new conceptual framework for understanding the mechanism of action of a variety of agents for the treatment of HCV. We present a robust and efficient numerical method that belongs to the family of adaptive stepsize methods and is implicit, a Rosenbrock type method that is highly suited to solve this problem. We provide a Graphical User Interface that applies this method and is useful for simulating viral dynamics during treatment with anti-HCV agents that act against HCV on the molecular level.

Highlights of drug - and herb- induced liver injury in the literature from 2016: how best to translate new information into clinical practice?

INTRODUCTION

Over 1500 papers on drug-induced liver injury (DILI) and herb-induced liver injury (HILI) were published in 2016, many of which have the potential to impact clinical practice. Areas covered: Clinical studies and case series that lent themselves to new concepts in diagnosing, and treating DILI were selected for inclusion. Epidemiology of DILI in large prospective registries was highlighted. Causality assessment of drug hepatotoxicity remains challenging, as seen with cases of OxyELITE Pro (OEP). In 2016 updates to the Roussel Uclaf Causality Assessment Method (RUCAM) were published to aid in the accuracy of diagnosing DILI/HILI. New reports of established hepatotoxins were again discussed in 2016, including genetic risk factors for DILI with respect to antituberculous agents. Expert opinion: 2016 marked a turning point in how much credence should be placed in the current causality assessment for DILI/HILI cases. Many recognized hepatotoxins are backed by a relatively few number of literature reports. Danan and Teschke make a strong case that an updated RUCAM should remain the gold standard for diagnosing DILI/HILI going forward, although the role of expert opinion is often still needed in cases where RUCAM falls short. The field of chemoinformatics continues to evolve while we await a truly predictive and diagnostic DILI biomarker.

Can we go for a shorter treatment course in chronic hepatitis C? More inspiring cases

Current interest in HCV therapy with direct acting antivirals is focused on shortening treatment length. We managed two cirrhotics who achieved virological cure after 4 weeks of ombitasvir/paritaprevir/ritonavir, dasabuvir, ribavirin treatment. Analysis to identify potential predictive factors for a successful outcome with a shorter treatment course was conducted.

Modeling HCV cure after an ultra-short duration of therapy with direct acting agents

BACKGROUND

Cases of sustained-virological response (SVR or cure) after an ultra-short duration (≤27 days) of direct-acting antiviral (DAA)-based therapy, despite HCV being detected at end of treatment (EOT), have been reported. Established HCV mathematical models that predict the treatment duration required to achieve cure do not take into account the possibility that the infectivity of virus produced during treatment might be reduced. The aim of this study was to develop a new mathematical model that considers the fundamental and critical concept that HCV RNA in serum represents both infectious virus (V_i) and non-infectious virus (V_ni) in order to explain the observation of cure with ultrashort DAA therapy.

METHODS

Established HCV models were compared to the new mathematical model to retrospectively explain cure in 2 patients who achieved cure after 24 or 27 days of paritaprevir, ombitasvir, dasabuvir, ritonavir and ribavirin or sofosbuvir plus ribavirin, respectively.

RESULTS

Fitting established models with measured longitudinal HCV viral loads indicated that in both cases, cure would not have been expected without an additional 3-6 weeks of therapy after the actual EOT. In contrast, the new model fits the observed outcome by considering that in addition to blocking V_i and V_ni production (ε∼0.998), these DAA + ribavirin treatments further enhanced the ratio of V_ni to V_i, thus increasing the log (V_ni/V_i) from 1 at pretreatment to 6 by EOT, which led to <1 infectious-virus particle in the extracellular body fluid (i.e., cure) prior to EOT.

CONCLUSIONS

This new model can explain cure after short duration of DAA + ribavirin therapy by suggesting that a minimum 6-fold increase of log (V_ni/V_i) results from drug-induced enhancement of the V_ni/V_i.