A randomized trial of 48 versus 24 weeks of combination pegylated interferon and ribavirin therapy in genotype 6 chronic hepatitis C.

BACKGROUND & AIMS: Genotype 6 chronic hepatitis C (HCV) is encountered predominantly in Southeast Asia and data on optimal treatment strategy is limited. This study was aimed at assessing the rate and predictors of sustained virological response (SVR) in genotype 6 chronic HCV following 48 and 24 weeks of pegylated interferon and ribavirin therapy. METHODS: This investigator-initiated, open-label randomized trial was conducted in Vietnam between 2008 and 2010. One hundred and five treatment-naïve HCV genotype 6 patients were randomized to either 48-week (N=70) or 24-week (N=35) duration of pegylated interferon (PEG-IFN) alfa-2a 180 mcg/week and ribavirin (RBV) 15mg/kg/day; 92 patients completed the study (63 in the 48-week and 29 in the 24-week group, respectively). Primary outcome was sustained virological response (SVR) as intention-to-treat analysis. RESULTS: There was no statistical difference in SVR between 48-week and 24-week treated groups (71% vs. 60%, respectively; p=0.24). In the 48-week and 24-week treatment groups, 81% and 80% of cases achieved rapid virological response (RVR) (p=0.86), and 86% and 80% achieved complete early virological response (p=0.45). Among those patients with RVR, SVR was in 86% (48-weeks), and 75% (24-weeks) of cases, whereas following non-RVR, only 8% of cases had an SVR with 48-week treatment duration. CONCLUSIONS: Overall, RVR was achieved in the majority of genotype 6 patients and, in those patients, similar and high rates of SVR were noted following 24-week and 48-week therapy. This observation, however, needs validation in a larger study to demonstrate non-inferiority of the shorter duration therapy. In non-RVR patients, even 48-week therapy achieved low SVR rates.

Sofosbuvir-ledipasvir with or without ribavirin for chronic hepatitis C genotype-1 and 6: real-world experience in Vietnam.

BACKGROUND: Therapy with sofosbuvir-ledipasvir (SOF-LDV) has been very effective in chronic HCV genotype-1 in clinical trials and several real-world cohorts. However, the safety and efficacy data of SOF-LDV for HCV genotype-6 is quite limited. METHODS: This open-label, clinical experience evaluated the safety and efficacy of SOF-LDV with or without ribavirin (RBV) for 12-24 weeks in patients with HCV genotype-1 (n=356) and genotype-6 (n=175) in Vietnam between September 2015 and May 2017. RESULTS: Among 539 patients evaluated for therapy, 531 patients completed treatment with either SOF-LDV for 12 weeks (n=284); SOF-LDV + RBV for 12 weeks (n=109); SOF-LDV for 24 weeks (n=36); or SOF-LDV + RBV for 24 weeks (n=102). 45% were male with a mean age of 56.3 (range 20-87) years. The mean HCV RNA was 4,370,000 IU/ml and 72.7% had high viral load of >800,000 IU/ml. 17.3% failed prior interferon-based therapy and 52.5% had advanced fibrosis (F3-4) as noted by transient elastography. The overall sustained virological response (SVR12) rate was 99.6% (529/531). Virological relapses occurred in two patients with genotype-1 in the SOF-LDV for 12 weeks and SOF-LDV + RBV for 24 weeks treatment groups. There was no significant difference in demographic data and treatment outcomes between patients with genotype-1 versus 6. Adverse events were mild with all SOF-LDV regimens, but appeared to be more common with 24-week treatment groups. CONCLUSIONS: SOF-LDV with or without RBV was highly effective and safe in Vietnamese patients with HCV genotype-1 and 6.

Ultra-deep sequencing reveals high prevalence and broad structural diversity of hepatitis B surface antigen mutations in a global population.

The diversity of the hepatitis B surface antigen (HBsAg) has a significant impact on the performance of diagnostic screening tests and the clinical outcome of hepatitis B infection. Neutralizing or diagnostic antibodies against the HBsAg are directed towards its highly conserved major hydrophilic region (MHR), in particular towards its "a" determinant subdomain. Here, we explored, on a global scale, the genetic diversity of the HBsAg MHR in a large, multi-ethnic cohort of randomly selected subjects with HBV infection from four continents. A total of 1553 HBsAg positive blood samples of subjects originating from 20 different countries across Africa, America, Asia and central Europe were characterized for amino acid variation in the MHR. Using highly sensitive ultra-deep sequencing, we found 72.8% of the successfully sequenced subjects (n = 1391) demonstrated amino acid sequence variation in the HBsAg MHR. This indicates that the global variation frequency in the HBsAg MHR is threefold higher than previously reported. The majority of the amino acid mutations were found in the HBV genotypes B (28.9%) and C (25.4%). Collectively, we identified 345 distinct amino acid mutations in the MHR. Among these, we report 62 previously unknown mutations, which extends the worldwide pool of currently known HBsAg MHR mutations by 22%. Importantly, topological analysis identified the "a" determinant upstream flanking region as the structurally most diverse subdomain of the HBsAg MHR. The highest prevalence of "a" determinant region mutations was observed in subjects from Asia, followed by the African, American and European cohorts, respectively. Finally, we found that more than half (59.3%) of all HBV subjects investigated carried multiple MHR mutations. Together, this worldwide ultra-deep sequencing based genotyping study reveals that the global prevalence and structural complexity of variation in the hepatitis B surface antigen have, to date, been significantly underappreciated.