Morven Cunningham

Systematic review: outcome of compensated cirrhosis due to chronic hepatitis C infection.

Aliment Pharmacol Ther 2010; 32: 344–355

Efficacy and safety of telaprevir in patients with genotype 1 hepatitis C infection

Chronic hepatitis C infection represents a significant and growing health problem worldwide. Patients with genotype 1 hepatitis C respond poorly to the current standard of care, pegylated interferon and ribavirin, which is frequently associated with unpleasant side effects. Consequently new agents with improved efficacy and tolerability are needed. The efficacy and safety of the direct-acting antiviral agent telaprevir in the treatment of genotype 1 hepatitis C infection have been demonstrated in a number of clinical trials. The addition of telaprevir to standard therapy considerably improves response rates and allows response-guided shortening of treatment duration in a substantial number of treatment-naïve patients. Side effects associated with telaprevir therapy include rash, anaemia, gastrointestinal disturbance and anorectal discomfort. Telaprevir-resistant variants have been identified in patients who have failed telaprevir-containing therapy, and whether selection of these variants will compromise future therapeutic options is currently unknown. The efficacy and safety of telaprevir in the treatment of the most challenging patients, including those with recurrent hepatitis C following liver transplantation and those co-infected with HIV, remains to be established.

Second generation direct antivirals and the way to interferon-free regimens in chronic HCV

Treatment for those infected with chronic hepatitis C virus [HCV] has until recently been hampered by the lack of therapies other than pegylated interferon and ribavirin, which have limited efficacy and a difficult side effect profile. To address this, multiple new direct acting antiviral drugs which specifically target the non-structural proteins involved in HCV replication are in phase II/III development. This review will discuss the HCV replication cycle, mechanisms of action of the new direct acting antiviral drugs, results from published trials into their efficacy and the potential for interferon free treatment regimens in the future.

Endothelin-1 as a mediator and potential biomarker for interferon induced pulmonary toxicity.

Endothelin-1 is a potent vasoconstrictor and a therapeutic target in pulmonary arterial hypertension. Endothelial cells are the physiological source of endothelin-1 but in vitro data from our group shows that interferons (IFNα, IFNβ or IFNγ) induce endothelin-1 in pulmonary vascular smooth muscle cells. IFNs are integral to innate immunity and their antiviral and immunomodulatory capability has been harnessed therapeutically; for example, IFNα plays a critical role in the treatment of chronic hepatitis C infection. However, in some patients, IFN causes pneumonitis and possibly irreversible pulmonary arterial hypertension. In this study, we found that of 16 patients undergoing a six-month course of IFNα therapy, two demonstrated considerably increased serum levels of endothelin-1. We propose that IFN therapy results in elevated levels of endothelin-1 in some patients and when clinically significant levels are reached, pulmonary side effects could ensue. This hypothesis can be easily tested in IFN-treated patients by measuring serum endothelin-1 levels and cardiopulmonary physiological parameters.

Development and validation of a "capture-fusion" model to study drug sensitivity of patient-derived hepatitis C.

Emerging therapies for chronic hepatitis C viral (HCV) infection involve inhibition of viral enzymes with drug combinations. Natural, or treatment‐induced, enzyme polymorphisms reduce efficacy. We developed a phenotyping assay to aid drug selection based on viral transfer from monocytes to hepatocytes. We studied HCV in monocytes from infected patients and developed a model in which patient‐derived HCV is “captured” by the cell line THP‐1 and replication assessed after fusion to hepatoma cells. We found that monocytes from HCV‐infected patients harbor virus that replicates when cells are fused to hepatocytes. THP‐1 cells incubated with infected sera capture HCV, which replicates when fused to hepatocytes. Inhibitable replication of all HCV genotypes was achieved (42 of 52 isolates). We measured sensitivity of telaprevir (TVR) and alisporivir (AVR) in different genotypes, and showed differences in 50% inhibitory concentration (IC50) correlating with clinical response (TVR IC50 for genotype (G)1 was 0.042 ± 0.003 vs. 0.117 ± 0.015 μM for G3, whereas AVR IC50 for G1 was 0.139 ± 0.013 vs. 0.044 ± 0.007 μM for G3). We tested TVR‐resistant viral isolates and identified changes in IC50. One patient with a poor clinical response to TVR and wild‐type viral sequence showed reduced TVR sensitivity in our assay. We studied samples from a 2‐week TVR monotherapy study in which 5 of 8 patients with G3 HCV did not respond whereas 3 of 8 patients did. The “capture‐fusion” assay correctly identified responders. Conclusion: The capture‐fusion model represents a promising new technique that may help identify appropriate treatment strategies for patients with chronic HCV infection. (Hepatology 2015;61:1192–1204)

SB 9200, a novel agonist of innate immunity, shows potent antiviral activity against resistant HCV variants

SB 9200 is a novel, first‐in‐class oral modulator of innate immunity that is believed to act via the activation of the RIG‐I and NOD2 pathways. SB 9200 has broad‐spectrum antiviral activity against RNA viruses including hepatitis C virus (HCV), norovirus, respiratory syncytial virus, and influenza and has demonstrated activity against hepatitis B virus (HBV) in vitro and in vivo. In phase I clinical trials in chronically infected HCV patients, SB 9200 has been shown to reduce HCV RNA by up to 1.9 log10. Here, we demonstrate the antiviral activity of SB 9200 against a HCV replicon system and patient derived virus. Using the HCV capture‐fusion assay, we show that SB 9200 is active against diverse HCV genotypes and is also effective against HCV derived from patients who relapse following direct‐acting antiviral treatment, including viruses containing known NS5A resistance‐associated sequences. These data confirm the broad antiviral activity of SB 9200 and indicate that it may have clinical utility in HCV patients who have failed to respond to current antiviral regimens.

P0703 : Pre-treatment ribavirin sensitivity correlates with treatment outcome in genotype 3 HCV

Background and Aims: New therapies for chronic HCV infection have substantially increased rates of sustained virological response (SVR). However relapse after therapy remains a problem, especially in patients with cirrhosis. We have developed a novel capture- fusion assay to study patient-derived HCV (1). Here we demonstrate that this assay can identify pre-treatment sofosbuvir (SOF), interferon (IFN) and ribavirin (RBV) sensitivity in patients with G3 HCV, and RBV sensitivity correlates with treatment outcome. Methods: Archived pre-treatment sera were obtained from 10 G3 patients treated with pegIFN/RBV, 4 with SVR and 6 who relapsed, and from 4 G3 patients treated with SOF/RBV, 3 with SVR and 1 who relapsed. THP-1 cells were exposed to donor serum, fused with Huh7.5 cells and treated with SOF, IFN or RBV before qPCR assessment of HCV replication. Results are given as mean ± sem and p values were calculated using Mann Whitney U test. Results: No difference in pre-treatment IFN sensitivity was seen between patients with SVR and those who relapsed after pegIFN/RBV (IFN IC50 0.61±0.11 IU/mL for patients with SVR versus 0.55±0.09 IU/mL for relapse, p = 0.61). However pre-treatment isolates from patients with SVR were significantly more sensitive to RBV than those from patients who relapsed (ribavirin IC50 0.62±0.05 mM for patients with SVR versus 1.25±0.13 m Mf or relapse, p = 0.01). Amongst patients treated with SOF/RBV, pre- treatment SOF sensitivity was similar between patients with SVR and relapse (SOF IC50 0.036±0.016 mM for SVR versus 0.023 m Mf or the patient who relapsed). However pre-treatment RBV sensitivity appeared greater in patients with SVR than relapse (RBV IC50 0.377±0.037 mM for SVR versus 1.049 mM for the patient who relapsed).

1145 PRE-TREATMENT PREDICTION OF TELAPREVIR RESPONSE USING A NOVEL CAPTURE-FUSION ASSAY FOR HCV REPLICATION

1145 PRE-TREATMENT PREDICTION OF TELAPREVIR RESPONSE USING A NOVEL CAPTURE-FUSION ASSAY FOR HCV REPLICATION M.E. Cunningham, A. Javaid, J.A. Waters, J. Davidson-Wright, J.L. Wong, T. Haque, M. Macartney, G. Dusheiko, W. Rosenberg, M. Jacobs, G.R. Foster. Digestive Diseases, Blizard Institute, Queen Mary, University of London, Department of Virology, Institute of Liver and Digestive Health, Division of Infection and Immunity, Royal Free and University College London, London, UK E-mail: m.e.cunningham@qmul.ac.uk

OC-024 Development and validation of a novel capture-fusion model for HCV replication

Introduction HCV replicates poorly in vitro, so testing of novel antiviral therapies currently relies on modified viral replicons, based on genotype (G)1, or the G2 JFH-1 virus. A model allowing patient virions to be cultured would facilitate drug discovery and allow direct sensitivity testing. Here we describe the development of a novel HCV replication assay, its validation using the antiviral agents alisporivir and telaprevir and its value in identifying responses to interferon and ribavirin. Methods CD14 (+) monocytes derived from patients with chronic HCV infection, or pre-stimulated THP-1 cells infected with serum from G1 and G3 HCV infected donors, were fused with HuH7 cells and treated with antiviral agents at various concentrations. The fused cells were maintained in tissue culture for up to 5 days, before extraction of HCV RNA and quantification by PCR. p Values were derived using the Mann–Whitney U test for comparison of non-parametric data. Results are expressed as mean±SEM. Results Replicating HCV from patients infected with diverse genotypes could be successfully transferred to HuH7 cells using the monocyte “capture-fusion” approach. RNA increased fivefold in fused cells and viral protein production as well as viral release could be demonstrated, confirming the presence of complete viral replication cycles in this new model. Treatment of G1 and G3 fused/infected Huh7 cells with escalating concentrations of alisporivir showed greater drug efficacy in cells infected with G3 than G1 (IC50 0.026±0.008 μM vs 0.109±0.02 μM, p=0.0286). Conversely, telaprevir showed greater efficacy in fused/infected cells with G1 than fused/infected cells with G3 HCV. Treatment with 0.1 μM telaprevir, which approximates its IC50 in replicon cells, resulted in a reduction of HCV RNA by 66.15±10.43% in G1 cells vs 21.56±3.16% in G3 infected cells (p=0.016). We examined sensitivity to interferon and ribavirin in samples from patients who did (N=3), or did not (N=4), respond to therapy. We found no significant difference in the viral sensitivity, suggesting that for interferon based therapies host factors play a more important role than virological response. Conclusion These data confirm the value of a capture-fusion model for HCV replication in studying the replication of patient-derived HCV and demonstrate that for interferon and ribavirin based treatments, host factors dominate the response. However viral response determines the clinical response to direct acting anti-viral agents. This technique may be useful in identifying the most appropriate treatment strategies for patients with HCV planning therapy with the new direct acting antiviral agents. Competing interests M Cunningham: None declared, A Javaid: None declared, J Waters: None declared, G Foster grant/research support from: Roche, Janssen, Tibotec, Novartis, Consultant for: Abbott, BI, BMS, Chughai, Janssen, Merck, Novartis, Roche, Tibotec.

PMO-167 Presence of viable HCV RNA in monocytes at the end of treatment predicts relapse in genotype 3 HCV infection

Introduction Although genotype (G)3 HCV is generally regarded as “easy to treat”, based on clinical trial data showing response rates of up to 80%, real world studies have shown substantially lower rates of treatment response (45%), particularly in patients with advanced fibrosis or cirrhosis. Most patients who fail treatment for G3 HCV initially respond to antiviral therapy, but relapse after the end of treatment. HCV RNA has been demonstrated in peripheral blood mononuclear cells from patients with chronic HCV, but whether viral replication occurs in these cells remains controversial. This study tests the hypothesis that viable HCV in monocytes at the end of treatment predicts relapse in patients with G3 HCV. Methods CD14 (+) monocytes from patients at the end of treatment for G3 HCV were isolated and fused with HuH7 cells. The fused cells were maintained in tissue culture for up to 5 days, before extraction of HCV RNA and quantification by PCR. p Values were derived using the Mann–Whitney U test for comparison of non-parametric data. Results are expressed as mean ± SEM. Results HCV RNA increased up to fivefold in fused compared to unfused monocytes. Viral protein production was demonstrated in fused cells by indirect immunofluorescence, confirming that viral replication occurs in the fused cells. Fused monocytes from patients who relapsed after treatment showed a significantly greater increase in HCV RNA than those from patients with a sustained virological response (246.8±103.9%, compared to 5±33.9%, p=0.02). Conclusion These data demonstrate that the presence of replication-competent HCV in monocytes at the end of treatment predicts relapse in patients with G3 HCV. Monocytes may act as a sanctuary site for HCV virions during interferon-based treatment, facilitating relapse after withdrawal of therapy. Competing interests M Cunningham: None declared, A Javaid: None declared, J Waters: None declared, G Foster Grant/Research Support from: Roche, Janssen, Tibotec, Novartis, Consultant for: Abbott, BI, BMS, Chughai, Janssen, Merck, Novartis, Roche, Tibotec.