Meta-analysis of patients with hepatitis C virus genotype 6: 48 weeks with pegylated interferon and ribavirin is superior to 24 weeks

Eliminating hepatitis C within low-income countries - The need to cure genotypes 4, 5, 6

Around 70 to 100 million people are chronically infected with HCV worldwide. HCV antiviral drug development has revolutionised the treatment of HCV, with several direct-acting antiviral agents offering patients the chance of cure after only 8-12 weeks of treatment. Drug development was initially focussed on HCV genotype 1 (GT1) infection, since this was the most prevalent worldwide, although clinical trials included all genotypes prevalent in the US and Europe. Because the earliest in vitro assays utilised the GT1b and 2 replicons, the initial classes of direct-acting antivirals (protease inhibitors, non-nucleotide polymerase inhibitors) were GT1-specific, albeit they had an effect on other less prevalent genotypes. Epidemiological data has shown the regional importance of other HCV genotypes. More than 50% of all HCV infections around the globe are not with GT1. The prevalence of HCV genotype 4 (GT4), 5 (GT5), and 6 (GT6) is increasing in North America and Europe due to migration from the Middle East, Africa and South-East Asia. With the successful development of the multi and pan-genotypic non-structural protein 5A inhibitors, second generation protease inhibitors and nucleotide non-structural protein 5B inhibitors comes a unique opportunity to achieve global HCV elimination. The goal of this review is to summarise the available information pertaining to GT4, GT5 and GT6, with a specific focus on direct-acting antiviral agents.

Open Label Study of 8 vs. 12 Weeks of Ledipasvir/Sofosbuvir in Genotype 6 Treatment Naïve or Experienced Patients

OBJECTIVES

Hepatitis C genotype 6 (HCV-GT6) is one of the most prevalent genotypes in Southeast Asia. Ledipasvir and sofosbuvir fixed-dose combination (LDV/SOF FDC) for 12 weeks has been shown to be effective for multiple HCV genotypes including treatment-naïve HCV-6. Our goal was to examine treatment outcomes in a diverse HCV-6 population.

METHODS

We prospectively enrolled 60 HCV-GT6 patients at four US centers. Treatment -naïve without cirrhosis patients received open-labeled LDV/SOF FDC orally once a day for 8 weeks; All cirrhotic and/or treatment-experienced patients received LDV/SOF FDC for 12 weeks. The primary outcome was sustained virological response 12 weeks after therapy (SVR12). Secondary outcomes were adverse events (AEs) and/or serious adverse events (SAEs). All patients gave written consent.

RESULTS

Overall mean age was 58±10 and 58% were male. All patients were Asian and foreign born. The 8-week group included 20 patients (33.3%) and the 12-week included 40 patients (66.7%). There were 2 (5%) patients with decompensation, 3 with liver cancer (7.5%), and 14 with prior treatment (35%) in the 12-week group. SVR12 was 95.0% for the 8-week group (19/20) and 95.0% for the 12-week group (38/40). AEs included fatigue (5%), insomnia (3.3%), headache (1.7%), and nausea (1.7%); however, all patients completed the intended treatment duration. There were two treatment-unrelated SAEs.

CONCLUSIONS

LDV/SOF FDC for 8 or 12 weeks was safe and effective for patients without cirrhosis or prior treatment failure as well as for patients with cirrhosis and/or prior treatment failure, respectively.

Ubiquitin in the activation and attenuation of innate antiviral immunity

Viral infection activates danger signals that are transmitted via the retinoic acid-inducible gene 1-like receptor (RLR), nucleotide-binding oligomerization domain-like receptor (NLR), and Toll-like receptor (TLR) protein signaling cascades. This places host cells in an antiviral posture by up-regulating antiviral cytokines including type-I interferon (IFN-I). Ubiquitin modifications and cross-talk between proteins within these signaling cascades potentiate IFN-I expression, and inversely, a growing number of viruses are found to weaponize the ubiquitin modification system to suppress IFN-I. Here we review how host- and virus-directed ubiquitin modification of proteins in the RLR, NLR, and TLR antiviral signaling cascades modulate IFN-I expression.

Current Treatment Options in Patients with Hepatitis C Virus Genotype 6

Approximately 3% of the world's population is chronically infected with hepatitis C virus (HCV). In some southeast Asian countries the prevalence of HCV (∼6%-7%) far exceeds that seen in the United States (1.8%). The lesser known HCV genotype 6 (HCV-6) is also common in patients from southeast Asia and the surrounding regions. Most data on direct-acting antivirals (DAAs) to date have been derived from clinical trials conducted in Western countries, where HCV-6 is rare. The standard of care for patients with HCV-6 is still pegylated interferon and ribavirin. However, data are emerging for several DAA combinations.

Peginterferon plus Ribavirin for HIV-infected Patients with Treatment-Naïve Acute or Chronic HCV Infection in Taiwan: A Prospective Cohort Study

Data are limited on the effectiveness and safety of peginterferon plus ribavirin in HIV-infected Asian patients with acute or chronic HCV infection. HIV-infected Taiwanese patients with acute HCV infection received peginterferon plus weight-based ribavirin for 24 weeks (n = 24), and those with chronic HCV genotype 1 or 6 (HCV-1/6) and HCV genotype 2 or 3 (HCV-2/3) infection received response-guided therapy for 12-72 and 24-48 weeks, respectively (n = 92). The primary endpoint was sustained virologic response (SVR), defined as undetectable HCV RNA 24 weeks off-therapy. The SVR rates were 83% and 72% in patients with acute and chronic HCV infection (p = 0.30), and 68% and 72% in patients with chronic HCV-1/6 and HCV-2/3 infection (p = 0.48), respectively. While no factors predicted SVR in acute HCV and chronic HCV-2/3 infection, age (odds ratio [OR] per 1-year increase: 0.88, 95% confidence interval [CI]: 0.78-0.99, p = 0.04), HCV RNA (OR per 1-log10 increase: 0.18, 95% CI: 0.03-0.98, p = 0.03), IL28B genotype (OR: 5.52, 95% CI: 1.55-12.2, p = 0.02), and RVR (OR: 9.62, 95% CI: 3.89-15.3, p = 0.007) predicted SVR in chronic HCV-1/6 infection. In conclusion, the SVR rates of peginterferon plus ribavirin for 24 weeks and for response-guided 12-72 weeks are satisfactory in HIV-infected Taiwanese patients with acute and chronic HCV infection.