HCV genotype 3: a wolf in sheep's clothing

Molecular epidemiology of hepatitis C virus genotypes in different geographical regions of Chinese mainland and a phylogenetic analysis

BACKGROUND

Hepatitis C virus (HCV) infection remains a major public health problem in Chinese mainland. Investigation of the distribution of genotypes contributed to the prevention, diagnosis and treatment of HCV infection. Therefore, we conducted a study on the distribution of HCV genotypes and phylogenetic analysis to provide an up-to-date understanding of the molecular epidemiology of genotypes in Chinese mainland.

METHODS

Our retrospective multicenter study enrolled 11,008 samples collected between August 2018 and July 2019 from 29 provinces/municipalities (Beijing, Hebei, Inner Mongolia, Shanxi, Tianjin, Gansu, Ningxia, Shaanxi, Xinjiang, Heilongjiang, Jilin Liaoning, Henan, Hubei Hunan, Anhui, Fujian, Jiangsu, Jiangxi, Shandong, Shanghai Zhejiang, Guangdong, Guangxi, Hainan, Chongqing, Guizhou, Sichuan and Yunnan). Phylogenetic analysis of each subtype was performed to infer the evolutionary relationship of sequences from diverse regions. Two independent samples t tests were used for the comparison of continuous variables, and chi-square tests were used for the comparison of categorical variables.

RESULTS

Four genotypes (1, 2, 3 and 6) were found, including 14 subtypes. HCV genotype 1 was dominant, accounting for 49.2%, followed by genotypes 2, 3 and 6, accounting for 22.4%, 16.4%, and 11.9%, respectively. Additionally, the top five subtypes were 1b, 2a, 3b, 6a and 3a. Proportions of genotypes 1 and 2 decreased while genotypes 3 and 6 increased over past years (P < 0.001). Genotypes 3 and 6 were concentrated in the population aged 30 to 50 years, and male carriers had lower proportions of subtypes 1b and 2a than female carriers (P < 0.01). Genotypes 3 and 6 were more prevalent in southern parts of Chinese mainland. Nationwide spreads of subtypes 1b and 2a were associated with sequences from northern parts of Chinese mainland, while subtypes 3a, 3b and 6a were associated with sequences from southern parts of Chinese mainland.

CONCLUSIONS

HCV subtypes 1b and 2a remained the most common subtypes in Chinese mainland, and their proportions decreased over the past years, while the proportions of genotypes 3 and 6 increased. Our investigation provided an accurate epidemiological picture of the circulating viral strains in Chinese mainland, contributing to the prevention, diagnosis and treatment of HCV infection.

TRIAL REGISTRATION

Not applicable.

Sofosbuvir-Based Therapies Achieved Satisfactory Virological Response in Chinese Individuals with Genotypes 3 and 6 Infections: A Real-World Experience

BACKGROUND

Previous studies have shown that sofosbuvir-based regimens yield high sustained virological response rates in patients with hepatitis C virus (HCV) infection except for genotype 3b complicated with cirrhosis. This real-world study aims to explore the efficacy and safety of sofosbuvir-based regimens in Chinese patients with genotypes 3 and 6 infections, especially the impact of ribavirin coadministration on sustained virological response in cirrhotic patients with genotype 3b infection.

METHODS

This is a retrospective cohort study that included 101 patients initiated on sofosbuvir-based regimens. The main endpoint of treatment was sustained virological response at posttreatment week 12 (SVR12).

RESULTS

Overall, the SVR12 rates were 95.0% (96/101); specifically, the rates were 100% in sofosbuvir, 88.2% in sofosbuvir+ribavirin, 100% in sofosbuvir+daclatasvir, 100% in sofosbuvir+daclatasvir+ribavirin, 95.0% in sofosbuvir/velpatasvir, and 97.1% in sofosbuvir/velpatasvir+ribavirin (p=0.534). The SVR12 rates were comparable in patients infected with genotypes 3 and 6 (93.2% versus 97.6%, p=0.339). The SVR12 rate was 93.9% in cirrhotic patients (31/33). Among those infected with genotype 3, the SVR12 rate was 91.7% (22/24); the rate was 95.0% in those with ribavirin coadministration regimens, which was numerically higher than the 75.0% in those without ribavirin. However, no statistical difference was found (p=0.312). In total, five patients failed to achieve SVR12, including 3 patients with genotype 3b infection treated with ribavirin coadministration regimens (one of them was cirrhotic), 1 cirrhotic patient with genotype 3k infection, and 1 noncirrhotic patient with genotype 6a infection. No severe adverse event occurred.

CONCLUSION

Real-world data show that sofosbuvir-based regimens are highly effective and safe for patients with HCV genotypes 3 and 6 infections.

Satisfactory virological response and fibrosis improvement of sofosbuvir-based regimens for Chinese patients with hepatitis C virus genotype 3 infection: results of a real-world cohort study

Background

Chronic hepatitis C virus (HCV) genotype (GT) 3 infection with advanced liver disease has emerged as a challenging to treat by direct-acting antivirals (DAAs), but the efficacy of DAAs in Chinese HCV-GT3 patients is rarely reported. This study aimed to analyze the efficacy of sofosbuvir (SOF)-based regimens in Chinese patients with HCV-GT3 and compensated liver disease.

Methods

This was a registered retrospective study. All patients had completed at least 12 weeks SOF-based regimens therapy (with or without RBV), and were followed up for at least 24 weeks after therapy discontinuation. The primary endpoint was sustained virological response 24 weeks after end of therapy (SVR24).

Results

A total of 102 patients who completed at least 12 weeks therapy were finally included, with 57 in SOF + Daclatasvir (SOF + DCV), 24 in SOF + DCV + ribavirin (RBV) and 21 in SOF/Velpatasvir (SOF/VEL). The total SVR24 rate was achieved in 90.20% (92/102), with 85.96% (49/57) in SOF + DCV, 91.67% (22/24) in SOF + DCV + RBV and 100.00% (21/21) in SOF/VEL. Among 10 relapsed patients (8 in SOF + DCV and 2 in SOF + DCV + RBV), the short course (12 weeks) of therapy and no RBV addition may be the leading cause. In this cohort, the SVR24 rate was not statistically different between patients with and without cirrhosis (81.82% [27/33] vs. 94.20% [65/69], P = 0.073). Additionally, both FIB-4 (4.03 vs. 2.08, P < 0.001) and APRI (2.15 vs. 0.68, P < 0.001) scores were significant improved from baseline to week 24 after completion of therapy, regardless of the presence of cirrhosis.

Conclusion

SOF-based regimens are highly effective in viral clearance and fibrosis remission for Chinese patients with HCV-GT3 infection. If available, SOF/VEL should be first considered.

Pharmacokinetic drug evaluation of velpatasvir plus sofosbuvir for the treatment of hepatitis C virus infection

INTRODUCTION

The fixed-dose combination therapy of sofosbuvir (SOF) plus velpatasvir (VEL) is the first pangenotypic, direct-acting antiviral (DAA), single-treatment regimen (STR) for the treatment of hepatitis C virus (HCV) infection to be commercialized. It is approved for the treatment of HCV genotypes 1, 2, 3, 4, 5, and 6. Following approval in 2016, new pharmacokinetic and pharmacodynamic data were reported, which led to important clinical applications. Areas covered: This review provides a summary of the pharmacokinetics, pharmacodynamics, efficacy and safety of SOF/VEL therapy for treatment of HCV infection. The topics covered include data regarding the drug's absorption, distribution, metabolism, excretion and antiviral activity strategies, such as clinical dose selection and treatment duration. Expert opinion: This novel combination therapy containing 400 mg of SOF plus 100 mg of VEL, taken orally, once daily, with or without food, has an excellent pharmacokinetic and pharmacodynamic profile. SOF/VEL achieved very high rates of sustained virological response in treatment-naive and treatment-experienced patients with chronic HCV genotype 1-6 infection, including those with compensated cirrhosis or HIV-1 co-infection.