Sofosbuvir-based interferon-free therapy for patients with HCV infection

Impact of IL28B gene polymorphism on efficacy and safety of direct acting antivirals in hepatitis C Egyptian patients

Background Hepatitis C virus infection is one of the major causes of liver cirrhosis and hepatocellular carcinoma worldwide. IL28B gene polymorphism has a direct relation to the response of interferon-based regimens. However, the effect of IL28B gene polymorphism on efficacy of the new direct acting antivirals used in treatment of chronic hepatitis C Egyptian patients hasn't been studied yet. Objective This study aimed to investigate the frequency of IL28B genotypes and impact of its polymorphism on the efficacy and safety of two direct acting antiviral regimens. Setting Patients were recruited form faculty of Medicine Ain shams research institute, Cairo, Egypt. Methods Easy to treat chronic hepatitis C Egyptian patients were included in this prospective study. Patients were randomized into two groups, group 1 received sofosbuvir plus daclatasvir and group 2 received paritaprevir, ombitasvir and ritonavir plus ribavirin. Both treatment regimens were given for 3 months. Laboratory evaluation and IL28B rs 12979860 genotyping were performed at baseline. Follow ups were performed monthly. Fibrosis was assessed at baseline and after treatment. Main outcome measures The frequency of IL28B genotypes and their correlation with safety and efficacy of direct acting antiviral regimens. Results CT genotype was present in 52.42% of patients while CC and TT genotypes were present in 28.16% and 19.42% of patients, respectively. IL28B genotypes weren't correlated to sustained virologic response in both treatment groups. Baseline fibroscan scores didn't show any significant relations with IL28B genotypes. Aspartate aminotransferase/alanine aminotransferase ratio increased significantly at the end of treatment in group1. CC genotype had shown higher ratio values at the end of treatment in Group 2. Conclusion CT genotype is the predominant genotype in easy to treat HCV Egyptian patients. IL28B genotypes hasn't any predictive value on the efficacy or the safety of direct acting antiviral regimens.

Sofosbuvir plus simeprevir treatment of recurrent genotype 1 hepatitis C after liver transplant

BACKGROUND

Patients with recurrent hepatitis C (HCV) infection post-liver transplant can be difficult to treat safely and effectively. A prior (COSMOS) study in patients with non-transplant HCV, using sofosbuvir plus simeprevir, had high efficacy and tolerability in treating patients with HCV genotype 1, even prior non-responders to interferon therapy and those with cirrhosis. Our aim was to evaluate the efficacy of sofosbuvir and simeprevir in patients with genotype 1 HCV post-liver transplant.

METHODS

In this prospective, observational study, patients received sofosbuvir 400 mg plus simeprevir 150 mg daily for 12 wk without ribavirin. The primary end point was a sustained virologic response 12 wk after the end of therapy.

RESULTS

Forty-two patients completed the treatment. Twenty-six percent started the treatment ≤ 6 months post-liver transplant. Nineteen percent of the included patients had cirrhosis, 14% with decompensation. At week 4 on the treatment, 21% of patients had detectable virus but at the end of the treatment, 100% were undetectable. Twelve weeks after the end of the treatment, 95% of the patients had undetectable hepatitis C. The regimen was generally well tolerated.

CONCLUSION

The oral regimen of sofosbuvir plus simeprevir without ribavirin is efficacious and well tolerated in the treatment of patients with genotype 1 hepatitis C post-liver transplant.

Enhancing our understanding of current therapies for hepatitis C virus (HCV)

Great progress has been made in understanding the HCV genome and its molecular virology. This understanding has culminated in the development of direct-acting antiviral (DAA) agents targeting HCV viral proteins. Telaprevir (TVR) and boceprevir (BOC) were the first DAAs introduced for treatment of genotype 1 HCV in 2011; when used in combination with pegylated interferon (pegIFN) and ribavirin (RBV), these protease inhibitors improved efficacy in patients with chronic HCV infection compared to the traditional dual therapy. However, this combination was associated with adverse events that often led to early termination of therapy. In late 2013, the FDA approved a second wave of DAAs, sofosbuvir (SOF) and simeprevir (SMV). The use of SOF with SMV opened the door for IFN-free combination regimens. This combination was highly efficacious and well tolerated in patients with HCV genotype 1. Sofosbuvir and ledipasvir (LDV) fixed-dose oral combination (FDC) therapy, and paritaprevir/ritonavir, ombitasvir and dasabuvir ± RBV were recently approved, elevating sustained virologic response (SVR) rates to over 95 %. We are anticipating the approval of additional IFN-free regimens with comparable efficacy and tolerability but with the addition of pangenotypic coverage, fewer drug-drug interactions, and a high barrier to resistance. This review will summarize current management for chronic HCV infection.

Characterization of the activity of 2'-C-methylcytidine against dengue virus replication

Dengue virus (DENV) is a severe mosquito-borne viral pathogen. Neither vaccines nor antiviral therapy is currently available to treat DENV infection. Nucleoside inhibitors targeting viral polymerase have proved promising for the development of drugs against viruses. In this study, we report a nucleoside analog, 2'-C-methylcytidine (2CMC), which exerts potent anti-DENV activity in DENV subgenomic RNA replicon and infectious systems, with an IC50 value of 11.2±0.3μM. This study utilized both cell-based and cell-free reporter assay systems to reveal the specific anti-DENV RNA polymerase activity of 2CMC. In addition, both xenograft bioluminescence-based DENV replicon and DENV-infected Institute of Cancer Research (ICR) suckling mice models evaluated the anti-DENV replication activity of 2CMC in vivo. Collectively, these findings provide a promising compound for the development of direct-acting antivirals against DENV infection.

Sofosbuvir: first global approval

Sofosbuvir (Solvadi™), a nucleotide analogue hepatitis C virus NS5B polymerase inhibitor, is under development with Gilead Sciences for the once-daily, oral treatment of chronic hepatitis C. Oral sofosbuvir has been approved in the US for the treatment of chronic hepatitis C as a component of a combination antiviral regimen. In addition, the European Medicines Agency's Committee for Medicinal Products for Human Use has recommended the approval of sofosbuvir for the treatment of chronic hepatitis C. This article summarizes the milestones in the development of sofosbuvir leading to this first approval for chronic hepatitis C.

Effects of sofosbuvir-based treatment, with and without interferon, on outcome and productivity of patients with chronic hepatitis C

BACKGROUND & AIMS

Interferon-based treatment of chronic hepatitis C virus (HCV) infection can negatively affect patient-reported outcomes (PROs) and work productivity (WP). We assessed these factors in patients with chronic hepatitis C treated with sofosbuvir and ribavirin, with or without pegylated interferon.

METHODS

The HCV-specific Quality of Life (Chronic Liver Disease Questionnaire-HCV version [CLDQ-HCV]), Functional Assessment of Chronic Illness Therapy-Fatigue, and Work Productivity and Activity Index: Specific Health Problem questionnaires were completed before, during, and after treatment of patients infected with HCV genotypes 2 or 3 who received sofosbuvir and ribavirin for 16 or 12 weeks (the FUSION study, n = 201) or patients infected with HCV genotype 1 who received pegylated interferon, sofosbuvir, and ribavirin for 12 weeks (the NEUTRINO study, n = 327).

RESULTS

Patients in each group of the FUSION study had similar PRO and WP scores at each time point (all comparisons, P > .05). Compared with baseline, patients had modest reductions in fatigue, HCV-specific quality of life, and WP and Activity Index scores during treatment (P = .02 to <.0001). However, by 4 weeks after treatment, all scores returned to baseline levels or higher. Subjects in the NEUTRINO study had greater reductions in these scores during treatment; most remained significant through 4 weeks after treatment (P < .05). Significant improvements in PROs were observed among patients with sustained virologic responses 12 weeks after treatment in the FUSION and NEUTRINO studies (all P < .05). In multivariate analyses after adjustment for confounders, interferon therapy was independently associated with worse PROs after 12 weeks of treatment.

CONCLUSIONS

On the basis of an analysis of 2 large clinical trials (FUSION and NEUTRINO), patient outcome and productivity are more negatively affected by the inclusion of pegylated interferon in treatment than by interferon-free regimens. Patients with sustained virologic responses 12 weeks after treatment had significant improvements in PROs in both studies.

Renal dysfunction in end-stage liver disease and post-liver transplant

Renal dysfunction is a frequent complication in patients with end-stage liver disease awaiting orthotopic liver transplantation and in the post-liver transplant period. Although the stereotypical form of renal dysfunction is the hepatorenal syndrome, other causes of acute kidney injury in this population include prerenal azotemia and acute tubular necrosis. Renal injury in a patient with cirrhosis is associated with a poor prognosis.

Efficacy and safety of sofosbuvir-based therapy for the treatment of chronic hepatitis C in treatment-naïve and treatment-experienced patients

Sofosbuvir, a hepatitis C virus (HCV) NS5B polymerase inhibitor, is a new direct-acting antiviral for chronic HCV infection. This systematic review and proportional meta-analysis examined the efficacy and safety of sofosbuvir-based therapy for chronic HCV infection in treatment-naïve and -experienced patients. Medline, Cochrane Database of Systematic Reviews, EMBASE and Web of Science databases were searched. Clinical trials examining sofosbuvir plus ribavirin (RBV) and pegylated interferon-α (peg-IFN) or sofosbuvir plus RBV among adults with chronic HCV infection were included. Data were extracted on virological responses including sustained virological response at post-treatment Week 12 (SVR12), relapse, treatment discontinuation due to an adverse event (AE), virological breakthrough during treatment, and AEs. One trial and 13 treatment arms/cohorts from seven studies met the criteria for analysis in treatment-naïve patients who were treated with sofosbuvir, RBV and peg-IFN; the SVR12 was 89% (95% CI 85-92%), relapse was 5% and the serious adverse event (SAE) rate was 4%. Six treatment arms/cohorts met the criteria for analysis in treatment-naïve patients who were treated with sofosbuvir and RBV; the SVR12 was 72% (95% CI 60-81%), relapse was 27% and the SAE rate was 3%. Three treatment arms/cohorts met the criteria for analysis in treatment-experienced patients who were treated with sofosbuvir and RBV; the SVR12 was 51% (95% CI 27-75%), relapse was 46% and the SAE rate was 4%. In conclusion, sofosbuvir-based treatment is effective and safe in treating chronic HCV infection, although the SVR12 of its combination with RBV, especially in treatment-experienced patients, requires improvement.

Update on hepatitis C virus resistance to direct-acting antiviral agents

Resistance to direct-acting antiviral (DAA) agents against hepatitis C virus (HCV) infection is driven by the selection of mutations at different positions in the NS3 protease, NS5B polymerase and NS5A proteins. With the exception of NS5B nucleos(t)ide inhibitors, most DAAs possess a low genetic barrier to resistance, with significant cross-resistance between compounds belonging to the same family. However, a specific mutation profile is associated with each agent or drug class and varies depending on the genotype/subtype (e.g., genotype 1b showed higher rates of sustained virological response (SVR) and a higher genetic barrier for resistance than genotype 1a). Moreover, some resistance mutations exist as natural polymorphisms in certain genotypes/subtypes at frequencies that require baseline drug resistance testing before recommending certain antivirals. For example, the polymorphism Q80K is frequently found among genotype 1a (19-48%) and is associated with resistance to simeprevir. Similarly, L31M and Y93H, key resistance mutations to NS5A inhibitors, are frequently found (6-12%) among NS5A genotype 1 sequences. In particular, the presence of these polymorphisms may be of relevance in poorly interferon-responsive patients (i.e., null responders and non-CC IL28B) under DAA-based therapies in combination with pegylated interferon-α plus ribavirin. The relevance of pre-existing resistance mutations for responses to interferon-free DAA therapies is unclear for most regimens and requires further study.

HCV F1/F2 patients: treat now or continue to wait

The treatment of chronic HCV is evolving rapidly. In 2014, three new oral antiviral agents, simeprevir, faldeprevir and sofosbuvir will become available for patients with HCV genotype 1. These agents have far less side effects than the first generation protease inhibitors telaprevir and boceprevir. Treatment will therefore be easier for patients to tolerate but still require peginterferon and ribavirin (PEGINF/RBV). The first IFN free therapy, sofosbuvir (SOF) and ribavirin (RBV), will also become available in 2014. This treatment is highly effective for patients with HCV genotype 2. However, SVR rates with SOF/RBV appear to be similar to that achieved with PEGINF/RBV in patients with HCV genotype 3. The first IFN-free all oral antiviral therapy combination for patients with HCV genotype 1 may be available late in 2014 or early 2015. The factors which should be considered when deciding whether to treat a patient with HCV now or to delay treatment until IFN free therapies are available is discussed.

The versatile nature of the 6-aminoquinolone scaffold: identification of submicromolar hepatitis C virus NS5B inhibitors

We have previously reported that the 6-aminoquinolone chemotype is a privileged scaffold to obtain antibacterial and antiviral agents. Herein we describe the design, synthesis, and enzymatic and cellular characterization of new 6-aminoquinolone derivatives as potent inhibitors of NS5B polymerase, an attractive and viable therapeutic target to develop safe anti-HCV agents. The 6-amino-7-[4-(2-pyridinyl)-1-piperazinyl]quinolone derivative 8 proved to be the best compound of this series, exhibiting an IC50 value of 0.069 μM against NS5B polymerase and selective antiviral effect (EC50 = 3.03 μM) coupled with the absence of any cytostatic effect (CC50 > 163 μM; SI > 54) in Huh 9-13 cells carrying a HCV genotype 1b, as measured by MTS assay. These results indicate that the 6-aminoquinolone scaffold is worthy of further investigation in the context of NS5B-targeted HCV drug discovery programs.

Daclatasvir: potential role in hepatitis C

Chronic hepatitis C virus (HCV) infection is responsible for the development of liver cirrhosis and hepatocellular carcinoma. It has been a tremendous burden on global health care systems. With the advent of a number of new direct-acting and host-targeting antiviral agents, current interferon-α- and ribavirin-based HCV therapy has started to move towards an interferon-sparing or even interferon-free strategy. In this regard, a recently identified NS5A inhibitor, daclatasvir, showed a great promise in clinical trials as another new class of direct-acting anti-HCV therapeutics, with a distinct mechanism of action. In this review, a variety of preclinical as well as clinical proof-of-concept studies of daclatasvir, including the studies of its discovery, mechanism of action, viral resistance, and host polymorphism profiles are reviewed. In addition, a role of daclatasvir in the future therapy for HCV patients is discussed briefly.