Hepatitis C virus treatment and liver transplantation in the era of new antiviral therapies

CIHR Canadian HIV Trials Network Coinfection and Concurrent Diseases Core Research Group: 2016 Updated Canadian HIV/Hepatitis C Adult Guidelines for Management and Treatment

Background. Hepatitis C virus (HCV) coinfection occurs in 20-30% of Canadians living with HIV and is responsible for a heavy burden of morbidity and mortality. Purpose. To update national standards for management of HCV-HIV coinfected adults in the Canadian context with evolving evidence for and accessibility of effective and tolerable DAA therapies. The document addresses patient workup and treatment preparation, antiviral recommendations overall and in specific populations, and drug-drug interactions. Methods. A standing working group with HIV-HCV expertise was convened by The Canadian Institute of Health Research HIV Trials Network to review recently published HCV antiviral data and update Canadian HIV-HCV Coinfection Guidelines. Results. The gap in sustained virologic response between HCV monoinfection and HIV-HCV coinfection has been eliminated with newer HCV antiviral regimens. All coinfected individuals should be assessed for interferon-free, Direct Acting Antiviral HCV therapy. Regimens vary in content, duration, and success based largely on genotype. Reimbursement restrictions forcing the use of pegylated interferon is not acceptable if optimal patient care is to be provided. Discussion. Recommendations may not supersede individual clinical judgement. Treatment advances published since December 2015 are not considered in this document.

Betulinic acid exerts anti-hepatitis C virus activity via the suppression of NF-κB- and MAPK-ERK1/2-mediated COX-2 expression

BACKGROUND AND PURPOSE

This study was designed to evaluate the effect of betulinic acid (BA), extracted from Avicennia marina, on the replication of hepatitis C virus (HCV) and to investigate the mechanism of this BA-mediated anti-HCV activity.

EXPERIMENTAL APPROACH

HCV replicon and infectious systems were used to evaluate the anti-HCV activity of BA. Exogenous COX-2 or knock-down of COX-2 expression was used to investigate the role of COX-2 in the anti-HCV activity of BA. The effects of BA on the phosphorylation of NF-κB and on kinases in the MAPK signalling pathway were determined. The anti-HCV activity of BA in combination with other HCV inhibitors was also determined to assess its use as an anti-HCV supplement.

KEY RESULTS

BA inhibited HCV replication in both Ava5 replicon cells and in a cell culture-derived infectious HCV particle system. Treatment with a combination of BA and IFN-α, the protease inhibitor telaprevir or the NS5B polymerase inhibitor sofosbuvir resulted in the synergistic suppression of HCV RNA replication. Exogenous overexpression of COX-2 gradually attenuated the inhibitory effect of BA on HCV replication, suggesting that BA reduces HCV replication by suppressing the expression of COX-2. In particular, BA down-regulated HCV-induced COX-2 expression by reducing the phosphorylation of NF-κB and ERK1/2 of the MAPK signalling pathway.

CONCLUSIONS AND IMPLICATIONS

BA inhibits HCV replication by suppressing the NF-κB- and ERK1/2-mediated COX-2 pathway and may serve as a promising compound for drug development or as a potential supplement for use in the treatment of HCV-infected patients.

Drug interactions and protease inhibitors used in the treatment of hepatitis C: how to manage?

PURPOSE

The first-generation protease inhibitors (PI) boceprevir and telaprevir combined with pegylated interferon have revolutionized the treatment of type-1 hepatitis C by increasing the rates of sustained virologic response. However, they induce drug interactions, and their clinical relevance is difficult to predict. This review compiles available data on drug-drug interactions (DDI) based on their pharmacokinetic and pharmacodynamic properties with the aim of assisting clinicians in managing DDI METHODS: PubMed, drug interaction databases and hepatology and infectious disease conference abstracts were systematically searched using the key search terms "interaction", "hepatitis C", "telaprevir" and "boceprevir". All known interactions were compiled and reclassified according to their pharmacokinetic and pharmacodynamic mechanisms. The state of knowledge of interaction mechanisms are reported and a therapeutic approach is proposed.

RESULTS

Boceprevir and telaprevir are both substrates and potent inhibitors of cytochrome P450 3A4 and the drug transporter P-glycoprotein. They induce overdosage but can sometimes decrease the effect of other drugs by inducing other cytochromes. Overdosage or low dosage mainly affects drugs with a narrow therapeutic range, such as immunosuppressants or antiretrovirals. The distribution and elimination of PI are unaffected by interactions. In terms of pharmacodynamic interactions, PI can trigger drug-induced QT interval prolongation, which means that clinicians should manage such risk factors as potassium/magnesium levels or avoid other QT-prolonging drugs.

CONCLUSIONS

Management of hepatitis C therapy is complex. The key to interpreting DDI data is a solid understanding of the pharmacokinetic and pharmacodynamic profiles of the drugs involved. Their ability to inhibit cytochrome P450 3A4 and prolong the QT interval can have significant clinical consequences. This review provides a practical guide to the safe and effective management of therapy with boceprevir and telaprevir.

Telaprevir or boceprevir triple therapy in patients with chronic hepatitis C and varying severity of cirrhosis

BACKGROUND

Risks and benefits of protease inhibitor (PI) (telaprevir or boceprevir) triple therapy in hepatitis C virus (HCV)-infected patients with mildly decompensated cirrhosis, including those wait-listed for liver transplantation (LT), are incompletely known.

AIM

To assess virological responses and safety of PI triple therapy in patients with mildly decompensated Child-Pugh (CP) CP ≥6 vs. compensated (CP = 5) cirrhosis.

METHODS

Multicentre cohort of 160 adults with cirrhosis treated with peginterferon/ribavirin (peg-IFN/RBV) plus telaprevir (69%) or boceprevir (31%), comparing outcomes between those with CP = 5 and CP ≥6.

RESULTS

Patients, 47% with CP ≥6 cirrhosis (CP range 6-10), received PI triple therapy for a targeted duration of 48 weeks. The cohort was median age 59 years, 32% female, 59% genotype 1a, 35% previous null/partial responders. Sustained virological response at 12 weeks (SVR12) was achieved by 35% of patients with CP ≥6 vs. 54% of those with CP = 5 (P = 0.02). CP = 5, achievement of rapid virological response and genotype 1b/other, independently predicted SVR12. Compared to those with CP = 5, patients with CP ≥6 had more peg-IFN dose reductions, eltrombopag use, transfusions and hospitalisations to manage adverse events (all P < 0.05). Overall, 67 (42%) discontinued treatment early. Nine wait-listed patients were treated for a median of 97 days (IQR 60-160) prior to liver transplantation and five achieved post-LT SVR.

CONCLUSIONS

In the presence of mild decompensation (Child-Pugh ≥6), SVR12 rates with protease inhibitor triple therapy are significantly reduced and adverse events increased. Thus, treatment with protease inhibitor triple therapy, if judged as necessary, should be undertaken with close monitoring and awareness of the significant risks.

Pretransplant and posttransplant treatment of hepatitis C virus infection with protease inhibitors

PURPOSE OF REVIEW

Considering the impact of recurrent hepatitis C after liver transplantation on patient and graft survival, we examine the current and potential use of protease inhibitors in the prevention and treatment of recurrent hepatitis C.

RECENT FINDINGS

In genotype-1-infected patients in the waiting list, triple therapy with boceprevir or telaprevir should be considered in compensated cirrhotics. However, tolerability of therapy is low, and side effects are frequent and potentially life-threatening. In posttransplant hepatitis C, available data suggest that triple therapy substantially increases the virological response. Interactions of protease inhibitors with immunosuppressants are considerable, especially between tacrolimus and telaprevir. Anemia seems to be particularly frequent with triple therapy after liver transplantation. Interferon (IFN)-free regimens seem to achieve a high antiviral effect with an excellent safety profile and will probably replace the current IFN-based treatments in a few years from now.

SUMMARY

Antiviral therapy with protease inhibitors will substantially increase the number of patients achieving sustained hepatitis C virus eradication, either before or after liver transplantation. However, side effects and drug-drug interactions will possibly hamper their applicability in both settings; thus, a careful selection and management of patients will be crucial. In the near future, combination of direct-acting antivirals will allow shorter, safer, and more effective IFN-free regimens.

Liver transplantation: past, present and future

The first human liver transplant operation was performed by Thomas Starzl in 1963. The next two decades were marked by difficulties with donor organ quality, recipient selection, operative and perioperative management, immunosuppression and infectious complications. Advances in each of these areas transformed liver transplantation from an experimental procedure to a standard treatment for end-stage liver disease and certain cancers. From the handful of pioneering programmes, liver transplantation has expanded to hundreds of programmes in >80 countries. 1-year patient survival rates have exceeded 80% and outcomes continue to improve. This success has created obstacles. Ongoing challenges of liver transplantation include those concerning donor organ shortages, recipients with more advanced disease at transplant, growing need for retransplantation, toxicities and adverse effects associated with long-term immunosuppression, obesity and NASH epidemics, HCV recurrence and the still inscrutable biology of hepatocellular carcinoma. This Perspectives summarizes this transformation over time and details some of the challenges ahead.

Review article: prescribing medications in patients with cirrhosis - a practical guide

BACKGROUND

Most drugs have not been well studied in cirrhosis; recommendations on safe use are based largely on experience and/or expert opinion, with dosing recommendations often based on pharmacokinetic (PK) changes.

AIM

To provide a practical approach to prescribing medications for cirrhotic patients.

METHODS

An indexed MEDLINE search was conducted using keywords cirrhosis, drug-induced liver injury, pharmacodynamics (PDs), PKs, drug disposition and adverse drug reactions. Unpublished information from the Food and Drug Administration and industry was also reviewed.

RESULTS

Most medications have not been adequately studied in cirrhosis, and specific prescribing information is often lacking. Lower doses are generally recommended based on PK changes, but data are limited in terms of correlating PD effects with the degree of liver impairment. Very few drugs have been documented to have their hepatotoxicity potential enhanced by cirrhosis; most of these involve antituberculosis or antiretroviral agents used for HIV or viral hepatitis. Paracetamol can be used safely when prescribed in relatively small doses (2-3 g or less/day) for short durations, and is recommended as first-line treatment of pain. In contrast, NSAIDs should be used cautiously (or not at all) in advanced cirrhosis. Proton pump inhibitors have been linked to an increased risk of spontaneous bacterial peritonitis (SBP) in cirrhosis and should be used with care.

CONCLUSIONS

Most drugs can be used safely in cirrhosis, including those that are potentially hepatotoxic, but lower doses or reduced dosing frequency is often recommended, due to altered PKs. Drugs that can precipitate renal failure, gastrointestinal bleeding, SBP and encephalopathy should be identified and avoided.

Combinations of simple baseline variables accurately predict sustained virological response in patients with recurrent hepatitis C after liver transplantation

BACKGROUND

The efficacy of antiviral therapy in patients with hepatitis C recurrence after liver transplantation (LT) is far from optimal and a careful selection of candidates with the best chances to achieve sustained virological response (SVR) is relevant. Moreover, investigating the effects of sustained viral clearance on clinical outcomes is particularly significant. We aimed to identify and combine the best baseline predictors of SVR and to assess the clinical outcomes of antiviral therapy after LT.

METHODS

We studied 144 hepatitis C virus (HCV)-infected LT recipients who underwent antiviral therapy following transplantation. Baseline predictors of SVR including donor and recipient interleukin IL28B (IL28B) rs12979860 genotype were evaluated, and the long-term effects of antiviral therapy on clinical outcomes were assessed.

RESULTS

The presence of an IL28B CC genotype with either low viral load (VL), young donor age, or cyclosporine A (CsA)-based immunosuppression identified individuals with 69-80 % probabilities of SVR. In contrast, only 20% of recipients with a CT/TT IL28B genotype and either high VL, old donor age, or non-CsA immunosuppression achieved an SVR (p = 0.004). Regarding clinical outcomes, the 5-year cumulative probability of graft loss was 2% for the SVR patients and 48% for non-responders (p < 0.001).

CONCLUSIONS

The use of simple combinations of baseline variables including IL28B polymorphisms identifies HCV-infected LT recipients with different probabilities of response to antiviral treatment. SVR is associated with improved clinical outcomes.

Management of the transplant recipient with chronic hepatitis C

More than one-third of listed potential liver recipients in the US are infected with the hepatitis C virus (HCV). Recurrence of infection with HCV after liver transplantation is associated with accelerated graft loss and diminished patient survival. Current HCV treatments using peginterferon and ribavirin either alone or with first generation protease inhibitors (telaprevir, boceprevir) are limited by suboptimal viral response, drug-drug interaction, and side effects, some of which may be graft- or life-threatening. Rapid advances in new drug therapy for HCV promise to improve outcomes, reduce side effects and drug-drug interaction, shorten treatment duration, and simplify treatment regimens.

CIHR Canadian HIV Trials Network Coinfection and Concurrent Diseases Core: Canadian guidelines for management and treatment of HIV/hepatitis C coinfection in adults

BACKGROUND

Hepatitis C virus (HCV) coinfection occurs in 20% to 30% of Canadians living with HIV, and is responsible for a heavy burden of morbidity and mortality. HIV-HCV management is more complex due to the accelerated progression of liver disease, the timing and nature of antiretroviral and HCV therapy, mental health and addictions management, socioeconomic obstacles and drug-drug interactions between new HCV direct-acting antiviral therapies and antiretroviral regimens.

OBJECTIVE

To develop national standards for the management of HCV-HIV coinfected adults in the Canadian context.

METHODS

A panel with specific clinical expertise in HIV-HCV co-infection was convened by The CIHR HIV Trials Network to review current literature, existing guidelines and protocols. Following broad solicitation for input, consensus recommendations were approved by the working group, and were characterized using a Class (benefit verses harm) and Level (strength of certainty) quality-of-evidence scale.

RESULTS

All HIV-HCV coinfected individuals should be assessed for HCV therapy. Individuals unable to initiate HCV therapy should initiate antiretroviral therapy to slow liver disease progression. Standard of care for genotype 1 is pegylated interferon and weight-based ribavirin dosing plus an HCV protease inhibitor; traditional dual therapy for 24 weeks (for genotype 2/3 with virological clearance at week 4); or 48 weeks (for genotypes 2-6). Therapy deferral for individuals with mild liver disease may be considered. HIV should not be considered a barrier to liver transplantation in coinfected patients.

DISCUSSION

Recommendations may not supersede individual clinical judgement.

Lucidone suppresses hepatitis C virus replication by Nrf2-mediated heme oxygenase-1 induction

Upon screening of plant-derived natural products against hepatitis C virus (HCV) in the replicon system, we demonstrate that lucidone, a phytocompound, isolated from the fruits of Lindera erythrocarpa Makino, significantly suppressed HCV RNA levels with 50% effective concentrations of 15 ± 0.5 μM and 20 ± 1.1 μM in HCV replicon and JFH-1 infectious assays, respectively. There was no significant cytotoxicity observed at high concentrations, with a 50% cytotoxic concentration of 620 ± 5 μM. In addition, lucidone significantly induced heme oxygenase-1 (HO-1) production and led to the increase of its product biliverdin for inducing antiviral interferon response and inhibiting HCV NS3/4A protease activity. Conversely, the anti-HCV activity of lucidone was abrogated by blocking HO-1 activity or silencing gene expression of HO-1 or NF-E2-related factor 2 (Nrf2) in the presence of lucidone, indicating that the anti-HCV action of lucidone was due to the stimulation of Nrf-2-mediated HO-1 expression. Moreover, the combination of lucidone and alpha interferon, the protease inhibitor telaprevir, the NS5A inhibitor BMS-790052, or the NS5B polymerase inhibitor PSI-7977, synergistically suppressed HCV RNA replication. These findings suggest that lucidone could be a potential lead or supplement for the development of new anti-HCV agent in the future.

Telaprevir-based triple therapy in liver transplant patients with hepatitis C virus: a 12-week pilot study providing safety and efficacy data

After liver transplantation (LT), the management of recurrent hepatitis C virus (HCV) infections still remains a major challenge. In HCV genotype 1 patients not undergoing transplantation, the introduction of protease inhibitor (PI)-based regimens has increased the sustained virological response rate significantly. This pilot study investigated both the safety and efficacy of telaprevir (TVR)-based triple therapy in HCV-infected LT patients with a special emphasis on drug-drug interactions between immunosuppressants and PIs. Safety and efficacy data were gathered for 12 weeks for 9 HCV-infected LT patients who were treated with a combination of TVR, pegylated interferon, and ribavirin (RBV) in parallel with immunosuppressive drugs such as tacrolimus (TAC; n = 4), cyclosporine A (CSA; n = 4), and sirolimus (SIR; n = 1). Seven of the transplant patients completed the 12 weeks of triple therapy. At week 4, 4 of the patients were found to be HCV RNA-negative, and importantly, 8 were found to be negative at week 12. During the 12-week course of triple therapy, short-term measurements of immunosuppressant trough levels required individual dose reductions in all patients (CSA, 2.5-fold; SIR, 7-fold; and TAC, 22-fold). Furthermore, two-thirds of the patients exhibited hematological side effects requiring RBV dose reductions, the administration of erythropoietin, or even blood transfusions. In conclusion, this pilot study provides evidence showing that TVR-based triple therapy is effective within the first 4 to 12 weeks in LT patients suffering from HCV genotype 1 recurrence, and it also provides evidence showing that drug-drug interactions between TVR and immunosuppressants can be handled appropriately through the close monitoring of trough levels and adequate dosage adjustments.