Practical management of boceprevir and immunosuppressive therapy in liver transplant recipients with hepatitis C virus recurrence. Antimicrob Agents Chemother. 2012;56:5728-5734. [PMID: 22908172 DOI: 10.1128/aac.01151-12]

In silico structure-based discovery of a SARS-CoV-2 main protease inhibitor

The Coronavirus Disease 2019 (COVID-19) pandemic caused by the novel lineage B betacoroanvirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in significant mortality, morbidity, and socioeconomic disruptions worldwide. Effective antivirals are urgently needed for COVID-19. The main protease (M^pro) of SARS-CoV-2 is an attractive antiviral target because of its essential role in the cleavage of the viral polypeptide. In this study, we performed an in silico structure-based screening of a large chemical library to identify potential SARS-CoV-2 M^pro inhibitors. Among 8,820 compounds in the library, our screening identified trichostatin A, a histone deacetylase inhibitor and an antifungal compound, as an inhibitor of SARS-CoV-2 M^pro activity and replication. The half maximal effective concentration of trichostatin A against SARS-CoV-2 replication was 1.5 to 2.7µM, which was markedly below its 50% effective cytotoxic concentration (75.7µM) and peak serum concentration (132µM). Further drug compound optimization to develop more stable analogues with longer half-lives should be performed. This structure-based drug discovery platform should facilitate the identification of additional enzyme inhibitors of SARS-CoV-2.

Drug Metabolism, Drug Interactions, and Drug-Induced Liver Injury in Living Donor Liver Transplant Patients

Living donor liver transplant (LDLT) fills a critically needed gap in the number of livers available for transplant. However, little is known about the functional recovery of the liver in the donor and in the recipient after surgery. Given that both donor and recipients are treated with several drugs, it is important to characterize the time course of recovery of hepatic synthetic, metabolic, and excretory function in these patients. In the absence of data from LDLT, information on the effect of liver disease on the pharmacokinetics of medications can be used as guidance for drug dosing in LDLT patients.

Concise review: Interferon-free treatment of hepatitis C virus-associated cirrhosis and liver graft infection

Chronic hepatitis C is a major reason for development of cirrhosis and hepatocellular carcinoma and a leading cause for liver transplantation. The development of direct-acting antiviral agents lead to (pegylated) interferon-alfa free antiviral therapy regimens with a remarkable increase in sustained virologic response (SVR) rates and opened therapeutic options for patients with advanced cirrhosis and liver graft recipients. This concise review gives an overview about most current prospective trials and cohort analyses for treatment of patients with liver cirrhosis and liver graft recipients. In patients with compensated cirrhosis Child-Pugh-Turcotte (CTP) class A, all approved agents are safe and SVR rates do not significantly differ from patients without cirrhosis in general. In patients with decompensated cirrhosis CTP class B or C, daclastasvir, ledipasvir, velpatasvir, and sofosbuvir are approved, and SVR rates higher than 90% can be achieved. Especially for patients with a model of end stage liver disease score higher than 15 and therefore eligible for liver transplantation, data is scarce. Reported SVR rates in patients with cirrhosis CTP class C are lower compared to patients with a less severe liver disease. In liver transplant recipients with a maximum of CTP class A, SVR rates are comparable to patients without LT. Patients with decompensated graft cirrhosis should be treated on an individual basis.

Multicentre experience using daclatasvir and sofosbuvir to treat hepatitis C recurrence - The ANRS CUPILT study

BACKGROUND & AIMS

HCV recurrence remains a major issue in the liver transplant field, as it has a negative impact on both graft and patient survival. The purpose of this study was to investigate the efficacy and safety of treating HCV recurrence with sofosbuvir (SOF) and daclatasvir (DCV) combination therapy.

METHODS

From October 2013 to March 2015, 559 liver recipients were enrolled in the prospective multicentre France REcherche Nord&Sud Sida-hiv Hépatites (ANRS) Compassionate use of Protease Inhibitors in viral C Liver Transplantation cohort. We selected 137 patients with an HCV recurrence receiving SOF and DCV, whatever the genotype or fibrosis stage. The use of ribavirin and the duration of therapy were at the investigator's discretion. The primary efficacy end point was a sustained virological response (SVR) 12weeks after the end of treatment.

RESULTS

The SVR rate 12weeks after completing treatment was 96% under the intention-to treat analysis and 99% when excluding non-virological failures. Only two patients experienced a virological failure. The serious adverse event (SAE) rate reached 17.5%. Four patients (3%) stopped their treatment prematurely because of SAEs. Anaemia was the most common AE, with significantly more cases in the ribavirin group (56% vs. 18%; p<0.0001). A slight but significant reduction in creatinine clearance was reported. No clinically relevant drug-drug interactions were noted, but 52% of patients required a change to the dosage of immunosuppressive drugs.

CONCLUSIONS

Treatment with SOF plus DCV was associated with a high SVR12 and low rates of serious adverse events among liver recipients with HCV recurrence.

LAY SUMMARY

The recurrence of hepatitis C used to be the first cause of graft failure in infected liver transplanted recipients. Our study demonstrates the great efficacy of one combination of new all-oral direct-acting antiviral, sofosbuvir and daclatasvir, to treat the recurrence of hepatitis C on the graft. Ninety-six per cent of recipients were cured. The safety profile of this combination seemed to be good, especially no relevant drug-drug interaction with immunosuppressive drugs.

Treatment of severe recurrent hepatitis C after liver transplantation in HIV infected patients using sofosbuvir-based therapy

BACKGROUND

For liver transplant recipients with hepatitis C virus (HCV) and human immunodeficiency virus (HIV) co-infection, recurrence after LT is associated with a higher risk of graft loss than for HCV mono-infected patients. Prior HCV treatment options were limited by side effects and drug-drug interactions.

AIM

To evaluate treatment outcomes with sofosbuvir (SOF)-based therapy among HIV/HCV coinfected liver transplant recipients.

METHODS

Access to SOF and ribavirin (RBV) prior to regulatory approval was attained via an international compassionate access program for transplant recipients with a life expectancy of 1 year or less in the absence of HCV treatment. This report focuses on the short and longer term outcomes in HCV-HIV co-infected liver transplant recipients.

RESULTS

Twenty patients were treated, nine with early severe recurrence and 11 with cirrhosis. Eleven patients received SOF and RBV, one SOF, RBV and Peg-interferon, three SOF, RBV and simeprevir and five SOF, RBV and daclatasvir. Of the 18 patients who completed treatment, 16 (89%) achieved sustained virological response 12 weeks after the end of treatment (SVR12). Liver function tests (including bilirubin and albumin) improved significantly over time. Nineteen serious adverse events occurred in eight (40%) patients, none of them related to SOF. Two patients died during treatment and another, 1 year after the end of therapy, due to progressive end-stage liver disease. Importantly, HIV suppression was not compromised. No significant drug-drug interactions were reported.

CONCLUSIONS

Sofosbuvir-based regimens are safe, well-tolerated and provide high rates of SVR in HCV-HIV co-infected patients with severe recurrence after-liver transplant.

Multicenter Experience with Boceprevir or Telaprevir to Treat Hepatitis C Recurrence after Liver Transplantation: When Present Becomes Past, What Lessons for Future?

Background and aims

First generation protease inhibitors (PI) with peg-interferon (PEG-IFN) and ribavirin (RBV) have been the only therapy available for hepatitis C virus (HCV) genotype 1 infection in most countries for 3 years. We have investigated the efficacy and tolerance of this triple therapy in transplanted patients experiencing a recurrence of HCV infection on the liver graft.

Patients

This cohort study enrolled 81 liver transplant patients (Male: 76%, mean age: 55.8±9.7 years) with severe HCV recurrence (F3 or F4: n = 34 (42%), treatment experienced: n = 44 (54%)), treated with boceprevir (n = 36; 44%) or telaprevir (n = 45; 56%). We assessed the percentages of patients with sustained virological responses 24 weeks after therapy (SVR24), and safety.

Results

The SVR24 rate was 47% (telaprevir: 42%; boceprevir: 53%, P = ns). At baseline, a normal bilirubin level (p = 0.0145) and albumin level >35g/L (p = 0.0372) and an initial RBV dosage of ≥800 mg/day (p = 0.0033) predicted SVR24. During treatment, achieving an early virological response after 12 weeks was the strongest independent factor to predict SVR24 (p<0.0001). A premature discontinuation of anti-HCV therapy due to a serious adverse event (SAE) was observed in 22 patients (27%). Hematological toxicity, infections and deaths were observed in 95%, 28% and 7% of patients, respectively. A history of post-LT antiviral therapy and thrombocytopenia (<50G/L) during treatment were both independent predictors of the occurrence of infections or SAE (p = 0.0169 and p = 0.011).

Conclusions

The use of first generation PI after liver transplantation enabled an SVR24 rate of 47% in genotype 1 patients, but induced a high rate of SAE. The identification of predictive factors for a response to treatment, and the occurrence of SAE, have enabled us to establish limits for the use of this anti-HCV therapy in the transplant setting.

Hepatitis C virus recurrence after liver transplantation: how to treat and when

Chronic hepatitis C (CHC) is an important cause of cirrhosis and hepatocellular carcinoma and a common indication of liver transplantation (LT). Recurrence of hepatitis C occurs universally after LT with an accelerated course of the natural history of CHC in the graft. Treatment of hepatitis C before transplantation is the most effective strategy because it prevents graft reinfection, but applicability is low with pegylated interferon regimens. Treatment after LT is the strategy more frequently used. A sustained viral response (SVR) is achieved by one-third of those treated with dual therapy and is associated with better outcomes after LT. Triple therapy with protease inhibitors after LT has efficacy to 60%-70% of SVR but is associated with higher rates of secondary effects and drug-drug interactions that require an intensified and frequent monitoring of calcineurin inhibitors during treatment. In the near future, interferon-free regimens with new oral antiviral drugs will likely prevent viral reinfection before or after LT, and shorter treatment regimens and less toxicity are expected.

Management of Hepatitis C Post-liver Transplantation: a Comprehensive Review

Infection with hepatitis C virus (HCV) is a common cause of chronic liver disease, and HCV-related cirrhosis and hepatocellular carcinoma are the leading causes for liver transplantation in the Western world. Recurrent infection of the transplanted liver allograft is universal in patients with detectable HCV viremia at the time of transplant and can cause a spectrum of disease, ranging from asymptomatic chronic infection to an aggressive fibrosing cholestatic hepatitis. Recurrent HCV is more aggressive in the post-transplant population and is a leading cause of allograft loss, morbidity, and mortality. Historically, treatment of recurrent HCV has been limited by low rates of treatment success and high side effect profiles. Over the past few years, promising new therapies have emerged for the treatment of HCV that have high rates of sustained virological response without the need for interferon based regimens. In addition to being highly effective, these treatments have higher rates of adherence and a lower side effect profile. The purpose of this review is to summarize current therapies in recurrent HCV infection, to review the recent advances in therapy, and to highlight areas of ongoing research.

Interferon-free antiviral treatment of chronic hepatitis C in the transplant setting

Interferon-based regimens with first-generation protease inhibitors have a limited efficacy and an unfavorable safety profile. Combination therapies with two or more second-generation direct-acting antivirals plus/minus ribavirin revolutionized treatment strategies in patients chronically infected with hepatitis C virus. In this rapidly evolving era, patients in the transplant setting benefit from interferon-free treatment regimens. Scientific societies can barely keep up with this development, making it necessary to update the clinical guidelines by the American and European Associations for the Study of Liver Diseases within short periods. This review presents and discusses the currently available data of the use of interferon-free treatment in the setting of liver transplantation. However, costs, different reimbursement strategies, and health-care options cannot be answered by guidelines and recommendations from scientific societies. Further investigator-initiated trials are needed to individualize treatment concepts.

Management of post transplant hepatitis C in the direct antiviral agents era

Hepatitis C virus (HCV) infection is one of the main indications for liver transplantation. Viral recurrence occurs in all patients with detectable serum HCV RNA at the time of transplantation leading to cirrhosis in 20-30% of patients within 5 years. Viral eradication using antiviral therapy has been shown to improve patient and graft survival. Pegylated interferon (PEG-IFN) and ribavirin (RBV) antiviral therapy achieved SVR in around 30% of transplant recipients. In the non-transplant setting, first generation NS3/4 protease inhibitors, boceprevir or telaprevir associated with PEG-IFN and RBV, has improved the SVR rates to 75% in genotype 1 infected patients. However, tolerability and drug-drug interactions with calcineurin inhibitors are both limiting factors of their use in transplant recipients. In the non-transplant patients, using new direct-acting antiviral therapy has dramatically improved the efficacy of antiviral C therapy over recent years leading to SVR rates over 90% in phase II and III clinical trials, without PEG-IFN and/or RBV. Preliminary results in transplant patients showed better efficacy, better tolerability and less drug-drug interactions.

Boceprevir in liver transplant recipients

BACKGROUND

There has been increasing interest in using protease inhibitors with pegylated interferon and ribavirin to treat recurrent hepatitis C (HCV) disease in liver transplant recipients.

METHODS

We retrospectively evaluated the safety and efficacy in liver transplant recipients treated for recurrent hepatitis C genotype 1 with the combination of peginterferon, ribavirin and boceprevir.

RESULTS

Twenty liver transplant recipients were treated for recurrent hepatitis C. Baseline alanine aminotransferase, total bilirubin and HCV RNA values (± SD) were 67.5 (±50.9) mg/dl, 1.78 (±1.99) U/L, and 16 955 510 (±21 620 675) IU/ml. Anaemia was a common adverse event requiring epoetin in 16 of 20 recipients and ribavirin dose reductions in 17 of 20 recipients. One-third of recipients required a blood transfusion. Filgrastim was used in 11 of 20 patients (55%) and eltrombopag in two of 20 recipients (10%) over the course of treatment. Serum creatinine level increased significantly from a baseline value of 1.33 mg/dl to 1.59 mg/dl at week 20 of boceprevir (P < 0.005). The overall sustained viral response (SVR) was 50%. Of the 14 patients who had a viral load less than 1000 IU/ml at week 4 of boceprevir, the SVR was 71%. The SVR was 83% of the 11 patients who had undetectable viral levels at week 4 of boceprevir.

CONCLUSIONS

Antiviral therapy utilizing boceprevir in liver transplant recipients requires close monitoring. Anaemia and neutropenia were common requiring growth factors in most recipients. On-treatment viral responses appear promising but long-term data are needed.

Optimal therapy in hepatitis C virus liver transplant patients with direct acting antivirals

Hepatitis C virus (HCV) end stage liver disease is a main indication for liver transplantation (LT). Recurrent HCV always occurs when patients are transplanted with a detectable viral load, leading to cirrhosis in 20-30% of patients within 5 years. Achieving a sustained virological response (SVR) with antiviral treatment is the only way to improve patient and graft survival. Dual therapy based on pegylated interferon and ribavirin (PEG-IFN/RBV) was the standard of care for many years with limited efficacy and a poor safety profile. The addition of first generation NS3/4 protease inhibitors (PI) improved SVR rates from 30 to 50-60%. But the occurrence of serious adverse events and drug-drug interactions with calcineurin inhibitors have both been limiting factors for their use during LT. The preliminary results of the use of second generation direct acting antivirals (DAA) in transplant patients showed better efficacy with an SVR rate >70%. The pre- and post-transplantation safety profile is good. Although fewer drug-drug interactions are expected, some new DAA still interact with immunosuppressive drugs. Certain questions such as the use of RBV or the optimal duration of therapy have still not been resolved but should be answered by the many ongoing studies in the coming year.

Telaprevir drug monitoring during antiviral therapy of hepatitis C graft infection after liver transplantation

BACKGROUND & AIMS

Recurrence of hepatitis C virus (HCV) infection after orthotopical liver transplantation (OLT) is common and associated with reduced graft and patient survival. The protease inhibitor telaprevir may enhance virological response rates in patients after OLT in combination with pegylated interferon-alfa and ribavirin. Pharmacokinetic studies have shown significant drug-drug interactions between telaprevir and immunosuppression (IS), but telaprevir pharmacokinetics in OLT patients with IS are unknown. Aim of the present study was to analyse telaprevir plasma concentrations in patients with HCV genotype 1 infection after OLT in comparison to patients without OLT and IS.

METHODS

Five patients with HCV genotype 1 infection after OLT and 37 HCV genotype 1-infected patients patients without prior OLT were treated with telaprevir 2250 mg daily, ribavirin 1000/1200 mg daily and pegylated interferon-alfa-2a 180 μg once weekly (triple therapy). Telaprevir plasma concentrations were analysed by liquid chromatography-electrospray-ionization-tandem mass spectrometry. HCV RNA was assessed by automatized reverse-transcription polymerase chain-reaction.

RESULTS

Median (range) telaprevir plasma concentrations of TW 4, 8 and 12 were 3970 (1980-4430) ng/ml and 2520 (1870-8730) ng/ml in patients after OLT and ciclosporin- or tacrolimus-based IS, respectively, as compared to 2790 (1870-3140) in non-OLT patients (P = 0.3). In one patient with tacrolimus-based IS, telaprevir dose had to be adjusted to achieve virological response. Telaprevir plasma concentrations were steady at treatment weeks 4, 8 and 12 in patients with and without IS.

CONCLUSIONS

Telaprevir drug monitoring may be necessary in patients with tacrolimus-based IS in patients with HCV graft infection after OLT.

Management of viral hepatitis in liver transplant recipients

Recurrence of viral hepatitis after liver transplantation (LT) can progress to graft failure and lead to a decrease in long-term survival. Recently, there have been remarkable improvement in the treatment of chronic hepatitis B (CHB) using potent antiviral agents. Combination of hepatitis B immunoglobulin and potent antiviral therapy has brought marked advances in the management of CHB for liver transplant recipients. Post-transplant antiviral therapy for hepatitis C virus infection is generally reserved for patients showing progressive disease. Acheiving a sustained virological response in patients with LT greatly ameliorates graft and overall survival, however this only occurs in 30% of transplant recipient using pegylated interferon and ribavirin (RBV). Direct acting antivirals such as protease inhibitors, polymerase or other non-structural proteins inhibitors are anticipated to establish the new standard of care for transplant recipients. In liver transplant recipients, hepatitis E virus infection is an uncommon disease. However, it can lead to chronic hepatitis and cirrhosis and may require retransplantation. Recently, 3-month course of RBV monotherapy has been reported as an effective treatment. This review focuses on the recent management and therapeutic approaches of viral hepatitis in liver transplant recipient.

Efficacy of new direct acting antivirals in transplant recipients and patients with advanced disease

The development of new direct acting antivirals constitutes a clinical revolution in the field of hepatitis C therapy and, most probably, in the history of Hepatology. Difficult-to-treat patients, such as cirrhotics or patients in the peri-transplant setting, will clearly benefit from these therapies, particularly from interferon-free all-oral combinations. However, despite the substantial improvement of the hepatitis C drug market, access to these therapies will likely be different around the world due to economic restrictions. This review aims to clarify the current stage of different antiviral strategies (with or without interferon) in these difficult populations by analysing specific efficacy and safety results in patients with cirrhosis, patients on the waiting list for liver transplantation and recipients with hepatitis C recurrence after liver transplantation. Hitherto, some important challenges still remain unanswered in these patients and will need to be assessed in clinical practice, such as the evaluation of safety and efficacy in advanced cirrhotic patients with portal hypertension, the impact (if any) of viral clearance on clinical outcomes in patients with decompensated liver disease, the role of ribavirin in all-oral combinations, the relevance of the development of multi-drug viral resistant strains and the drug-drug interaction profiles of these drugs, especially after liver transplantation.

Recurrent HCV after liver transplantation-mechanisms, assessment and therapy

Chronic HCV infection is the leading indication for liver transplantation. However, as a result of HCV recurrence, patient and graft survival after liver transplantation are inferior compared with other indications for transplantation. HCV recurrence after liver transplantation is associated with considerable mortality and morbidity. The development of HCV-related fibrosis is accelerated after liver transplantation, which is influenced by a combination of factors related to the virus, donor, recipient, surgery and immunosuppression. Successful antiviral therapy is the only treatment that can attenuate fibrosis. The advent of direct-acting antiviral agents (DAAs) has changed the therapeutic landscape for the treatment of patients with HCV. DAAs have improved tolerability, and can potentially be used without PEG-IFN for a shorter time than previous therapies, which should result in better outcomes. In this Review, we describe the important risk factors that influence HCV recurrence after liver transplantation, highlighting the mechanisms of fibrosis and the integral role of hepatic stellate cells. Indirect and direct assessment of fibrosis, in addition to new antiviral therapies, are also discussed.

Treatment options in patients with decompensated cirrhosis, pre- and post-transplantation

Interferon-based treatments have a poor safety profile and limited efficacy in patients with advanced liver disease and in patients with hepatitis C (HCV) recurrence after liver transplantation (LT). Despite the recent approval of the first interferon-free regimen, which will be followed by several other interferon-free combinations in 2014 and 2015, data in patients with advanced cirrhosis and hepatitis C after LT are still limited. One study has already proven the concept that graft HCV infection can be prevented in a significant proportion of patients by treating them with sofosbuvir and ribavirin while awaiting LT. Two interferon-free regimens have also demonstrated a high efficacy in patients with hepatitis C recurrence after transplantation. Before these treatment strategies can be implemented in clinical practice, a few issues need to be addressed: (1) safety and efficacy of new antivirals in patients with decompensated cirrhosis, (2) the impact of viral clearance on liver function, (3) the potential consequences of virological failure (and the selection of multi-drug resistant HCV strains) in patients with decompensated cirrhosis or with severe hepatitis C recurrence after LT, and (4) drug-drug interactions (DDI) profiles. Finally, in the transplant setting it is also relevant to learn which strategy is most cost-effective in minimizing the negative impact of hepatitis C: preventing graft infection by treating patients before transplantation or treating hepatitis C recurrence after LT.

[Drug-drug interaction with telaprevir or boceprevir in liver transplant patients: about four cases]

Boceprevir and telaprevir are both direct-acting antivirals indicated, as part of combination therapy for the management of chronic hepatitis C virus (HCV) genotype 1 infection. Transplanted patients treated with anticalcineurines (tacrolimus and cyclosporine) are confronted with major risks of interactions. Indeed, these antiviral are strong inhibitors of the enzyme cytochrome 3A4/A5, responsible for the metabolisme of ciclosprine and tacrolimus. The literature gives evidence of the dangerousness of this drug-drug interaction. We report four clinical cases illustrating the dosage adaptations at liver transplant patients and treated by telaprevir or boceprevir. To protect the immunosuppressive efficiency, a multidisciplinary care and narrow monitoring of the interaction between immunosuppressing agents and protease inhibitors were necessary.

Advances in therapy for HIV/hepatitis C virus-coinfected patients in the liver transplant setting

Complications of cirrhosis due to hepatitis C virus (HCV) are increasing, and liver transplantation (LT) is the most effective treatment for those with liver decompensation or small hepatocellular carcinoma. However, for patients with human immunodeficiency virus (HIV) coinfection, barriers to LT exist. This is related to the poorer survival rates post-LT (55% at 5 years) and, up until this year, the limited options for treating those coinfected LT recipients with progressive recurrent HCV disease, the commonest reason for reduced survival. The newly approved antiviral therapies sofosbuvir and simeprevir, with significantly improved efficacy and markedly better safety and tolerability in HIV and transplant patients, offer the opportunity to transform the outcomes of HIV/HCV-coinfected patients with liver complications. Additional new therapies, anticipated within the year, are expected to further simplify the management of coinfected patients in the transplant setting.

Hepatitis C virus reinfection after liver transplantation: Is there a role for direct antiviral agents?

Recurrence of hepatitis C virus (HCV) infection following liver transplantation (LT) is almost universal and can accelerate graft cirrhosis in up to 30% of patients. The development of effective strategies to treat or prevent HCV recurrence after LT remains a major challenge, considering the shortage of donor organs and the accelerated progression of HCV in LT recipients. Standard antiviral therapy with pegylated-interferon plus ribavirin is the current treatment of choice for HCV LT recipients, even though the combination is not as effective as it is in immunocompetent patients. A sustained virological response in the setting of LT improves patient and graft survival, but this is only achieved in 30%-45% of patients and the treatment is poorly tolerated. To improve the efficacy of pre- and post-transplant antiviral therapy, a new class of potent direct-acting antiviral agents (DAAs) has been developed. The aim of this review is to summarize the use of DAAs in LT HCV patients. PubMed, Cochrane Library, MEDLINE, EMBASE, Web of Science and clinical trial databases were searched for this purpose. To date, only three clinical studies on the topic have been published and most of the available data are in abstract form. Although a moderately successful early virological response has been reported, DAA treatment regimens were associated with severe toxicity mitigating their potential usefulness. Moreover, the ongoing nature of data, the lack of randomized studies, the small number of enrolled patients and the heterogeneity of these studies make the results largely anecdotal and questionable. In conclusion, large well-designed clinical studies on DAAs in HCV LT patients are required before these drugs can be recommended after transplantation.

Management of Hepatitis C Before and After Liver Transplantation in the Era of Rapidly Evolving Therapeutic Advances

Management of hepatitis C (HCV) in liver transplantation (LT) population presents unique challenges. Suboptimal graft survival in HCV+ LT recipients is attributable to universal HCV recurrence following LT. Although eradication of HCV prior to LT is ideal for the prevention of HCV recurrence it is often limited by adverse events, particularly in patients with advanced cirrhosis. Antiviral therapy in LT candidates needs careful monitoring, and prophylaxis with HCV antibodies is ineffective. Early antiviral therapy after LT has been investigated, but no clear benefit has been demonstrated. Protocol liver biopsy is generally recommended in HCV+ LT recipients, and antiviral therapy can be considered in those with severe/progressive HCV recurrence. Sustained virological response (SVR) can be achieved in approximately 30% of LT recipients with pegylated interferon/ribavirin (PEG-IFN/RBV) with survival benefit, but adverse effects are common. Favorable patient characteristics for response to therapy include non-1 genotype, previously untreated, low baseline HCV-RNA, and donor IL28B genotype CC. Direct acting antiviral (DAA)-based triple therapy is associated with higher rates of SVR, but with similar or slightly higher rates of side effects, and immunosuppressive regimens need to be closely monitored and adjusted during the treatment period. Notably, the safety and efficacy of HCV treatment are very likely to improve with newer generation DAA. The benefit of immunosuppressive strategy on the natural history HCV recurrence has not been well elucidated. Based upon available evidence, cyclosporine A (CSA), mycophenolate mofetil (MMF), and sirolimus appear to have a neutral or small beneficial impact on HCV recurrence. Donor interleukin 28 B (IL28B) polymorphisms appear to impact the course and treatment outcomes in recurrent HCV. Retransplantation should be considered for patients with reasonable survival probability.

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.

Drug-drug interactions with oral anti-HCV agents and idiosyncratic hepatotoxicity in the liver transplant setting

Studies of boceprevir and telaprevir based antiviral therapy in liver transplant (LT) recipients with hepatitis C genotype 1 infection have demonstrated dramatic increases in tacrolimus, cyclosporine, and mTOR inhibitor exposure. In addition to empiric dose reductions, daily monitoring of immunosuppressant blood levels is required when initiating as well as discontinuing the protease inhibitors to maximize patient safety. Although improved suppression of HCV replication is anticipated, 20 to 40% of treated subjects have required early treatment discontinuation due to various adverse events including anemia (100%), infection (30%), nephrotoxicity (20%) and rejection (5 to 10%). Simeprevir and faldaprevir will likely have improved efficacy and safety profiles but potential drug interactions with other OATP1B1 substrates and unconjugated hyperbilirubinemia are expected. In contrast, sofosbuvir and daclatasvir based antiviral therapy are not expected to lead to clinically significant drug-drug interactions in LT recipients but confirmatory studies are needed. Liver transplant recipients may also be at increased risk of developing drug induced liver injury (DILI). Establishing a diagnosis of DILI in the transplant setting is very difficult with the variable latency, laboratory features and histopathological manifestations of hepatotoxicity associated with a given drug, the need to exclude competing causes of allograft injury, and the lack of an objective and verifiable confirmatory test. Nonetheless, a heightened awareness of the possibility of DILI is warranted in light of the large number of medications used in LT recipients and the potential adverse impact that DILI may have on patient outcomes.

Management of HCV transplant patients with triple therapy

Hepatitis C virus (HCV) infection is one of the leading causes of end-stage liver disease and the main indication for liver transplantation (LT) in most countries. All patients who undergo LT with detectable serum HCV RNA experience graft reinfection. Between 20 and 30% of patients have developed cirrhosis at 5 years post-LT. The outcome of transplant patients with cirrhosis on the graft is severe, with a rate of decompensation at 1 year of approximately 40%. To date, retransplantation is the only option in patients with decompensated liver disease. Until 2011, standard antiviral therapy with pegylated interferon (PEG-IFN) and ribavirin (RBV), was the only effective therapy. Obtaining a sustained virological response (SVR) in patients with LT greatly improves overall and graft survival but this only occurs in 30% of transplanted patients. Direct acting antivirals (DAAs) such as protease inhibitors (PI), polymerase or other non-structural proteins inhibitors represent a new era in HCV associated liver disease. Although their use in the field of LT will certainly be essential there are some limitations because of safety and tolerance. One limitation is the potential interaction with calcineurin inhibitors. We describe the results of triple therapy with boceprevir (BOC) or telaprevir (TVR) for efficacy and safety and comment on future therapeutic strategies in liver transplant recipients.

Safety and efficacy of protease inhibitors to treat hepatitis C after liver transplantation: a multicenter experience

BACKGROUND & AIMS

Protease inhibitors (PI) with peginterferon/ribavirin have significantly improved SVR rates in HCV G1 patients. Their use to treat HCV recurrence after liver transplantation (LT) is a challenge.

METHODS

This cohort study included 37 liver transplant recipients (male, 92%, age 57 ± 11 years), treated with boceprevir (n=18) or telaprevir (n=19). The indication for therapy was HCV recurrence (fibrosis stage ≥F2 (n=31, 83%) or fibrosing cholestatic hepatitis (n=6, 16%).

RESULTS

Eighteen patients were treatment-naive, five were relapsers and fourteen were non-responders to dual therapy after LT. Twenty-two patients received cyclosporine and fifteen tacrolimus. After 12 weeks of PI therapy, a complete virological response was obtained in 89% of patients treated with boceprevir, and 58% with telaprevir (p=0.06). The end of treatment virological response rate was 72% (13/18) in the boceprevir group and 40% (4/10) in the telaprevir group (p=0.125). A sustained virological response 12 weeks after treatment discontinuation was observed in 20% (1/5) and 71% (5/7) of patients in the telaprevir and boceprevir groups, respectively (p=0.24). Treatment was discontinued in sixteen patients (treatment failures (n=11), adverse events (n=5)). Infections occurred in ten patients (27%), with three fatal outcomes (8%). The most common adverse effect was anemia (n=34, 92%), treated with erythropoietin and/or a ribavirin dose reduction; thirteen patients (35%) received red blood cell transfusions. The cyclosporine dose was reduced by 1.8 ± 1.1-fold and 3.4 ± 1.0-fold with boceprevir and telaprevir, respectively. The tacrolimus dose was reduced by 5.2 ± 1.5-fold with boceprevir and 23.8±18.2-fold with telaprevir.

CONCLUSIONS

Our results suggest that triple therapy is effective in LT recipients, particularly those experiencing a severe recurrence. The occurrence of anemia and drug-drug interactions, and the risk of infections require close monitoring.

Successful anti-hepatitis C virus therapy with telaprevir in an HIV/hepatitis C virus co-infected patient with a severe recurrence of hepatitis C virus infection on the liver graft

We report, for the first time, the outcome of anti-hepatitis C virus (HCV) triple therapy with telaprevir in an HIV/HCV co-infected transplanted patient. After liver transplantation, the patient experienced a severe HCV recurrence with fibrosing cholestatic hepatitis, and anti-HCV therapy with pegylated interferon alpha 2a, ribavirin and telaprevir was initiated. A sustained virological response was achieved after 48 weeks of anti-HCV therapy. Drug-drug interactions between antiretroviral therapy, immunosuppressive agents and anti-HCV therapy could be managed.

The importance of drug-drug interactions in the DAA era

With the licensing of the direct acting antivirals telaprevir and boceprevir the topic of drug-drug interactions has come to the forefront. These first generation hepatitis C virus protease inhibitors are metabolized by and inhibit the key drug metabolizing enzyme CYP3A4, which means that knowledge of drug-drug interactions has become an essential component of the evaluation of a patient starting triple therapy. The number of potential co-medications means that many drugs will be used in hepatitis C virus patients where there are no pharmacokinetic study data. Here we have to use the data that are available and seek to extrapolate to unstudied drugs using key principles of clinical pharmacology (disposition characteristics, concentration-effect relationships, therapeutic window) in order to give some guidance for management of patients. This is a rapidly moving area in hepatitis C therapy, both in terms of understanding the drug interaction profile of telaprevir and boceprevir, interaction mechanisms that sometimes appear counterintuitive and that may involve enzymes other than CYP3A4 or transporters, but then seeking to understand the interaction potential of the next wave of drugs that will soon be with us.

Treatment of chronic hepatitis C virus infection after liver transplantation

Chronic hepatitis C virus infection is a leading cause of end stage liver disease and one of the leading indications for liver transplantation. Furthermore, hepatitis C virus recurrence is universal post-transplant leading to decreased graft and patient survival. Recurrent disease related to hepatitis C virus can lead to between 20 and 30% of patients developing recurrent cirrhosis within 5 years. Treatment options with antiviral therapy are limited and are associated with a significant side-effect profile, suboptimal tolerability and inferior response rates. Attention has therefore turned to strategies that can reduce hepatitis C virus recurrence rates post-transplant. Approximately only 30% of patients will achieve a sustained virologic response with current therapy with pegylated interferon and ribavirin. Successful hepatitis C virus eradication is the only factor associated with improved graft and patient survival post liver transplantation. Here we provide an overview of antiviral treatment in patients in the transplant arena and the potential opportunities and challenges with the introduction of new directly acting antivirals in G1 patients.

[Pharmacokinetic interactions of telaprevir with other drugs]

Telaprevir is a new direct-acting antiviral drug for the treatment of hepatitis C virus (HCV) infection and is both a substrate and an inhibitor of cytochrome P450 (CYP450) isoenzymes. With the introduction of this new drug, assessment of drug-drug interactions has become a key factor in the evaluation of patients under treatment for HCV infection. During the treatment of this infection, many patients require other drugs to mitigate the adverse effects of anti-HCV drugs and to control other comorbidities. Moreover, most patients coinfected with HIV and HCV require antiretroviral therapy during treatment for HCV. Physicians should therefore be familiar with the pharmacokinetic properties of direct-acting antivirals for HCV treatment and their potential drug-drug interactions. The present article reviews the available information to date on the interactions of telaprevir with other drugs and provides recommendations for daily clinical practice.

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.

Update on donor-derived infections in liver transplantation

Advances in surgical techniques, immunosuppressive medications, and robust infectious disease prophylaxis have resulted in liver transplantation becoming the treatment of choice for patients with end-stage liver disease and unresectable hepatocellular carcinoma. Nonetheless, organ transplantation is not without risk. Unexpected donor-derived disease transmission is a newly recognized risk that complicates approximately 0.2% of all organ transplants. We review the epidemiology of donor-derived infectious diseases and methods of risk mitigation with a focus on liver transplantation.

Management of recurrent hepatitis C in orthotopic liver transplant recipients

End-stage liver disease and hepatocellular carcinoma from chronic hepatitis C are the most common indications for orthotopic liver transplantation and the incidence of both are projected to increase over the next decade. Recurrent hepatitis C virus infection of the allograft is associated with an accelerated progression to cirrhosis, graft loss, and death. This article presents an overview of the natural history of hepatitis C virus recurrence in liver transplant recipients and guidance on optimal management strategies.

Review article: the treatment of genotype 1 chronic hepatitis C virus infection in liver transplant candidates and recipients

BACKGROUND

Recently, the therapeutic landscape with regard to anti-HCV therapy has changed dramatically. The new directly acting anti-virals (DAAs) have demonstrated improved sustained virological response (SVR) compared with pegylated-interferon and ribavirin.

AIM

To examine and present the latest data with regard to anti-viral therapy in genotype 1 HCV-positive transplant candidates and recipients.

METHODS

An electronic search using Medline was performed. Search terms included 'HCV, DAA and protease inhibitor' in combination with 'treatment pre-transplantation' and 'treatment post-transplantation'.

RESULTS

Patients with advanced fibrosis and cirrhosis have inferior SVR rates compared with patients with minimal fibrosis. A low accelerating dose regimen (LADR) of pegylated interferon and ribavirin (PR) appears to be a safe therapeutic option. Side effects also appear to be more pronounced in patients with advanced disease. Data from the large registration studies with triple therapy (boceprevir or telaprevir plus PR) demonstrated improved SVR rates even in patients with advanced disease, although virological relapse rates were highest amongst these patients. In transplant recipients, initial data are being reported on the use of triple therapy, and although no SVR data are available, promising results are accruing. The drug-drug interactions appear to be manageable. Side effects in particular anaemia appear to be markedly increased in the posttransplant setting.

CONCLUSIONS

The use of the new DAAs in patients with advanced fibrosis/cirrhosis pretransplant and posttransplant appears possible, with manageable side effects and drug-drug interactions, and improved early virological response rates. We recommend that these patients are managed in centres with the appropriate expertise.

Current management and perspectives for HCV recurrence after liver transplantation

Hepatitis C virus (HCV) infection is one of the leading causes of end-stage liver disease and the main indication for liver transplantation (LT) in most countries. All patients who undergo LT with detectable serum HCV RNA experience graft reinfection. Between 20 and 30% of patients develop cirrhosis within 5 years post-LT. The outcome of transplant patients with cirrhosis on the graft is severe, with a rate of decompensation at 1 year of around 40%. To date, retransplantation is the only option for patients who develop decompensation. Until 2011, standard antiviral therapy, using pegylated interferon (PEG-IFN) and ribavirin (RBV), was the only effective therapy. Obtaining a sustained virological response (SVR) in the setting of LT greatly improves overall and graft survival, but this only concerns 30% of transplanted patients. Direct-acting antivirals (DAA) such as protease inhibitors, polymerase or other non-structural proteins inhibitors represent a new era in HCV-associated liver disease. Although their use in the field of liver transplantation seems to be essential, there are some limitations due to safety and tolerance. One limitation is the potential interaction with calcineurin inhibitors. We describe the preliminary results of triple therapy with boceprevir or telaprevir in terms of efficacy and safety in liver transplant recipients.