Future anti‐HBV strategies Gane, Edward J.
Liver international,
January 2017, 2017-01-00, 20170101, Letnik:
37, Številka:
S1
Journal Article
Recenzirano
Odprti dostop
Although current oral antivirals can maintain viral suppression and reduce the risk of liver‐related complications, lifelong therapy is associated with high cost, risk of breakthrough and potential ...toxicity. There is a need to develop a finite course of treatment which can provide sustained off‐treatment virological and clinical response. The likely marker of such a clinical HBV CURE would be HBsAg clearance, but in addition cccDNA elimination would be required to prevent future reactivation (ie complete HBV cure). Chronic HBV infection is characterised by high viral and antigen burden and inadequate host immune responses, both of which will need to be overcome to achieve HBV CURE. Innovative approaches to restore innate and adaptive immune responses against HBV currently in clinical development include therapeutic vaccines, TLR‐7 and TLR‐8 agonists. In future, strategies to reverse T‐cell exhaustion such as checkpoint inhibitors may be feasible. Currently, the only antivirals in clinical use are the HBV polymerase inhibitors. However, many other steps of HBV virion life cycle can be targeted by small molecules, including inhibitors of HBV entry, nucleocapsid formation and virion assembly and release. siRNAs could inhibit many different steps by blocking multiple HBV transcripts. But, the ultimate goal will be to successfully eradicate or silence cccDNA. It is likely that successful HBV cure will require combination of immunomodulatory, antiviral and cccDNA silencing strategies. Efficacy, safety, route of administration and cost will ultimately determine the impact of these new regimens on the burden of HBV.
Global elimination of HBV is feasible thanks to the availability of a safe, effective and inexpensive vaccine. However, this will not help almost 300 million adults living with chronic HBV infection. ...Current therapy can reduce complications but is administered life-long and is associated with risk of breakthrough and potential cumulative toxicity. There is therefore great interest in developing new therapies which can achieve sustained disease remission after a finite course of treatment i.e. an HBV CURE. Steps of HBV life cycle other than the polymerase that are targeted by new direct antiviral therapies include HBV entry, HBV capsid assembly, HBV mRNA transcription and translation and HBsAg secretion. As chronic HBV infection is characterised by high viral load and antigen burden and inadequate host immune responses innovative approaches to restore innate and adaptive immune responses against HBV, are currently in clinical development. These include therapeutic vaccines and TLR agonists. It is likely that HBV Cure will require combinations of novel immunomodulatory and antiviral approaches. In the future, strategies which directly silence or eliminate cccDNA could provide a single agent cure. Efficacy, safety, route of administration and cost will ultimately determine the impact of these new regimens on the burden of HBV.
Abbreviations: ACTG: AIDS Clinical Trials Group network; ALT: alanine aminotransferase; ASGPR: Asialoglycoprotein Receptor; ASO: anti-sense oligonucleotide; CAM: capsid assembly modulator; CAM-A: capsid assembly modulator with abhorrent structure; CAM-N: capsid assembly modulator with normal structure; cccDNA: covalently closed circular DNA; CHB: chronic hepatitis B; c-Raf-1/MAP: cellular Rapidly Accelerated Fibrosarcoma-1/mitogen-activated protein kinase; DR1 and DR2: direct repeat sequences 1 and 2; ETV: entecavir; FDA: Food and Drug Administration; GalNAc: N-acetylgalactosamine; HBcrAg: hepatitis B core-related antigen; HBeAg: hepatitis B e antigen; HBIG: hepatitis B immunoglobulin; HBsAg: hepatitis B surface antigen; HBV: hepatitis B virus; HBV DNA: hepatitis B virus deoxyribonucleic acid; HCC: hepatocellular carcinoma; HDV: hepatitis delta virus; ir-AE: immune-related adverse events; LNA: locked nucleic acid; MAD: multiple ascending dose; mRNA: messenger ribonucleic acid; NAPs: nucleic acid polymers; NTCP: sodium taurocholate co-transporting polypeptide; PD-1: programmed death receptor 1; PD-L1: programmed death receptor ligand 1; pgRNA: pregenomic ribonucleic acid; R-CHOP: rituximab plus cyclophosphamide plus doxorubicin plus vincristine plus prednisolone; RISC: RNA-induced silencing complex; RNAi: ribonucleic acid interference; SAD: single ascending dose; siRNA: short (small) interfering ribonucleic acid; STOPs: S-antigen traffic-inhibiting oligonucleotide polymers; TAF: tenofovir alafenamide; TDF: tenofovir disoproxil; USD: United States dollars; WHO: World Health Organization
Currently, despite the use of a preventive vaccine for several decades as well as the use of effective and well-tolerated viral suppressive medications since 1998, approximately 250 million people ...remain infected with the virus that causes hepatitis B worldwide. Hepatitis C virus (HCV) and hepatitis B virus (HBV) are the leading causes of liver cancer and overall mortality globally, surpassing malaria and tuberculosis. Linkage to care is estimated to be very poor both in developing countries and in high-income countries, such as the United States, countries in Western Europe, and Japan. In the United States, by CDC estimates, only one-third of HBV-infected patients or less are aware of their infection. Some reasons for these low rates of surveillance, diagnosis, and treatment include the asymptomatic nature of chronic hepatitis B until the very late stages, a lack of curative therapy with a finite treatment duration, a complex natural history, and a lack of knowledge about the disease by both care providers and patients. In the last 5 years, more attention has been focused on the important topics of HBV screening, diagnosis of HBV infection, and appropriate linkage to care. There have also been rapid clinical developments toward a functional cure of HBV infection, with novel compounds currently being in various phases of progress. Despite this knowledge, many of the professional organizations provide guidelines focused only on specific questions related to the treatment of HBV infection. This focus leaves a gap for care providers on the other HBV-related issues, which include HBV's epidemiological profile, its natural history, how it interacts with other viral hepatitis diseases, treatments, and the areas that still need to be addressed in order to achieve HBV elimination by 2030. Thus, to fill these gaps and provide a more comprehensive and relevant document to regions worldwide, we have taken a global approach by using the findings of global experts on HBV as well as citing major guidelines and their various approaches to addressing HBV and its disease burden.
Background & Aims Patients infected with hepatitis C virus (HCV) genotype 1, 4, or 6, with or without cirrhosis, previously treated with peg-interferon and ribavirin, are a challenge to treat. We ...performed a phase 3 randomized controlled open-label trial to assess the effects of 12 or 16 weeks of treatment with once-daily elbasvir (an HCV NS5A inhibitor, 50 mg) and grazoprevir (an HCV NS3/4A protease inhibitor, 100 mg), in a fixed-dose combination tablet, with or without twice-daily ribavirin, in this patient population. Methods We analyzed data from 420 patients (35% with cirrhosis, 64% with a null or partial response to peg-interferon and ribavirin) who were randomly assigned (1:1:1:1) to groups given elbasvir and grazoprevir once daily, with or without twice-daily ribavirin, for 12 or 16 weeks, at 65 study centers in 15 countries in Europe, Asia, and Central and North America. Randomization was stratified by cirrhosis status and type of peg-interferon and ribavirin treatment failure. HCV RNA was measured using COBAS TaqMan v2.0. The primary end point was HCV RNA <15 IU/mL, 12 weeks after completion of treatment (SVR12). We aimed to determine whether the proportion of patients achieving an SVR12 in any group was greater than the reference rate (58%). Results With 12 weeks of treatment, an SVR12 was achieved by 92.4% of patients given elbasvir and grazoprevir and 94.2% of patients given elbasvir and grazoprevir with ribavirin. With 16 weeks of treatment, an SVR12 was achieved by 92.4% of patients given elbasvir and grazoprevir and 98.1% of patients given elbasvir and grazoprevir with ribavirin. Among patients treated for 12 weeks without ribavirin, virologic failure occurred in 6.8%, 0%, and 12.5% of patients with HCV genotype 1a, 1b, or 4 infection, respectively. Also among patients given elbasvir and grazoprevir for 12 weeks, virologic failure occurred in 0% of patients infected with HCV genotype 1 and 7.5% infected with HCV genotype 4, respectively, who relapsed after completing peg-interferon and ribavirin or with a null or partial response to peg-interferon and ribavirin. Among patients treated for 16 weeks who received ribavirin, there were no incidences of virologic failure. Common adverse events were fatigue (23.1%), headache (19.8%), and nausea (11.0%). Conclusions The combination tablet of elbasvir and grazoprevir, with or without ribavirin, was highly efficacious in inducing an SVR12 in patients with HCV genotype 1, 4, or 6 infection failed by previous treatment with peg-interferon and ribavirin, including patients with cirrhosis and/or a prior null response. The treatment was generally well tolerated. ClinicalTrials.gov Number: NCT02105701.
Hepatocellular carcinoma (HCC) is a heterogeneous inflammation-driven malignancy, which, despite significant advances in management, continues to portend a poor prognosis. Recent advances in basic ...and translational research have increasingly defined the role of the tumor microenvironment in the development and progression of HCC and facilitated the development of novel molecular targets. The hepatoma microenvironment is characterised by an immunosuppressive milieu of immune cells and tumor vasculature that is both structurally and functionally abnormal. Normalising the tumor microenvironment by adopting a multipronged approach that targets both carcinogenic processes and the immunosuppressive milieu has been supported by pre-clinical and clinical data. In this review, we summarise the current understanding of the hepatoma microenvironment, its influences and dynamic interactions with tumor cells, the vasculature and the gut. Finally, we discuss how manipulating the tumor microenvironment continues to shape the evolving landscape of HCC therapy.
Summary Background Treatment options are limited for patients infected by hepatitis C virus (HCV) with advanced liver disease. We assessed the safety and efficacy of ledipasvir, sofosbuvir, and ...ribavirin in patients with HCV genotype 1 or 4 and advanced liver disease. Methods We did an open-label study at 34 sites in Europe, Canada, Australia, and New Zealand. Cohort A included patients with Child-Turcotte-Pugh class B (CTP-B) or CTP-C cirrhosis who had not undergone liver transplantation. Cohort B included post-transplantation patients who had either no cirrhosis; CTP-A, CTP-B, or CTP-C cirrhosis; or fibrosing cholestatic hepatitis. Patients in each group were randomly assigned (1:1) using a computer-generated randomisation sequence to receive 12 or 24 weeks of ledipasvir (90 mg) and sofosbuvir (400 mg) once daily (combination tablet), plus ribavirin (600–1200 mg daily). The primary endpoint was the proportion of patients achieving a sustained virological response 12 weeks after treatment (SVR12). All patients who received at least one dose of study drug were included in the safety analysis and all patients who received at least one dose of study drug and did not undergo liver transplantation during treatment were included in the efficacy analyses. Estimates of SVR12 and relapse rates and their two-sided 90% CI (Clopper-Pearson method) were provided. This exploratory phase 2 study was not powered for formal comparisons among treatment groups; no statistical hypothesis testing was planned or conducted. The trial is registered with EudraCT (number 2013-002802-30) and ClinicalTrials.gov (number NCT02010255 ). Findings Between Jan 14, 2014, and Aug 19, 2014, 398 patients were screened. Of 333 patients who received treatment, 296 had genotype 1 HCV and 37 had genotype 4 HCV. In cohort A, among patients with genotype 1 HCV, SVR12 was achieved by 20 (87%, 90% CI 70–96) of 23 CTP-B patients with 12 weeks of treatment; 22 (96%, 81–100) of 23 CTP-B patients with 24 weeks of treatment; 17 (85%, 66–96) of 20 CTP-C patients (12 weeks treatment); and 18 (78%, 60–91) of 23 CTP-C patients (24 weeks treatment). In cohort B, among patients with genotype 1 HCV, SVR12 was achieved by 42 (93%, 84–98) of 45 patients without cirrhosis (12 weeks treatment); 44 (100%, 93–100) of 44 patients without cirrhosis (24 weeks treatment); 30 (100%, 91–100) of 30 CTP-A patients (12 weeks treatment); 27 (96%, 84–100) of 28 CTP-A patients (24 weeks treatment); 19 (95%, 78–100) of 20 CTP-B patients (12 weeks treatment); 20 (100%, 86–100) of 20 CTP-B patients (24 weeks treatment); one (50%, 3–98) of two CTP-C patients (12 weeks treatment); and four (80%, 34–99) of five CTP-C patients (24 weeks treatment). All five patients with fibrosing cholestatic hepatitis achieved SVR12 (100%, 90% CI 55–100). Among all patients with genotype 4 HCV, SVR12 was achieved by 14 (78%, 56–92) of 18 patients (12 weeks treatment) and 16 (94%, 75–100) of 17 patients (24 weeks treatment). Seven patients (2%) discontinued ledipasvir–sofosbuvir prematurely due to adverse events. 17 patients died, mainly from complications of hepatic decompensation. Interpretation Ledipasvir–sofosbuvir and ribavirin provided high rates of SVR12 for patients with advanced liver disease, including those with decompensated cirrhosis before or after liver transplantation. Funding Gilead Sciences.
An estimated million people have chronic hepatitis C virus (HCV) infection. With current treatment success rates, by 2030, more than 40% will be cirrhotic and the number of cases with end‐stage liver ...disease is projected to treble. Current standard‐of‐care is the combination of pegylated interferon plus ribavirin for 24–48 weeks. Unfortunately this is associated with poor efficacy (45% in HCV GT1; 75% in GT2 and 65% in GT 3) and tolerability. Many patients are either unsuitable for or decline current treatment infection because of the significant side‐effects associated with this treatment, including those with decompensated cirrhosis or sever psychiatric illness. It is hoped that the development of direct acting antiviral agents (DAAs) will address this huge unmet medical need. The addition of a protease inhibitor to pegylated interferon plus ribavirin is associated with increase in efficacy and shortened duration of therapy in patients with HCV GT1 and is likely to become the new standard‐of‐care. However, triple therapy will not be suitable for patients with non‐1 HCV infection, or contraindications to interferon. It is hoped that the combination of multiple DAAs which target different steps of HCV replication should provide interferon‐free treatment regimen. Current and planned studies will determine which combination (protease, nonnucleoside polymerase, nucleoside polymerase, NS5A, cyclophyllin B inhibitors), how many DAAs and duration of therapy will be required to optimise cure. It will also be important to minimise the emergence of multi‐resistance, which would jeopardise future retreatment options
Background and Aims
We evaluated the safety and efficacy of cilofexor (formerly GS‐9674), a small‐molecule nonsteroidal agonist of farnesoid X receptor, in patients with nonalcoholic steatohepatitis ...(NASH).
Approach and Results
In this double‐blind, placebo‐controlled, phase 2 trial, 140 patients with noncirrhotic NASH, diagnosed by magnetic resonance imaging–proton density fat fraction (MRI‐PDFF) ≥8% and liver stiffness ≥2.5 kPa by magnetic resonance elastography (MRE) or historical liver biopsy, were randomized to receive cilofexor 100 mg (n = 56), 30 mg (n = 56), or placebo (n = 28) orally once daily for 24 weeks. MRI‐PDFF, liver stiffness by MRE and transient elastography, and serum markers of fibrosis were measured at baseline and week 24. At baseline, median MRI‐PDFF was 16.3% and MRE‐stiffness was 3.27 kPa. At week 24, patients receiving cilofexor 100 mg had a median relative decrease in MRI‐PDFF of −22.7%, compared with an increase of 1.9% in those receiving placebo (P = 0.003); the 30‐mg group had a relative decrease of −1.8% (P = 0.17 vs. placebo). Declines in MRI‐PDFF of ≥30% were experienced by 39% of patients receiving cilofexor 100 mg (P = 0.011 vs. placebo), 14% of those receiving cilofexor 30 mg (P = 0.87 vs. placebo), and 13% of those receiving placebo. Serum gamma‐glutamyltransferase, C4, and primary bile acids decreased significantly at week 24 in both cilofexor treatment groups, whereas significant changes in Enhanced Liver Fibrosis scores and liver stiffness were not observed. Cilofexor was generally well‐tolerated. Moderate to severe pruritus was more common in patients receiving cilofexor 100 mg (14%) than in those receiving cilofexor 30 mg (4%) and placebo (4%).
Conclusions
Cilofexor for 24 weeks was well‐tolerated and provided significant reductions in hepatic steatosis, liver biochemistry, and serum bile acids in patients with NASH. ClinicalTrials.gov No. NCT02854605.
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