Sofosbuvir with peginterferon-ribavirin for 12 weeks in previously treated patients with hepatitis C genotype 2 or 3 and cirrhosis.

UNLABELLED: Sofosbuvir (SOF) in combination with ribavirin (RBV) for 12 or 24 weeks is the current standard of care for patients infected with hepatitis C virus (HCV) genotypes 2 and 3, respectively. However, in clinical trials treatment-experienced patients, particularly those with cirrhosis, had suboptimal sustained virological response (SVR) rates. We assessed the efficacy and safety of sofosbuvir plus peginterferon and ribavirin (SOF+Peg-IFN+RBV) administered for 12 weeks to treatment-experienced patients with HCV genotypes 2 and 3, with and without cirrhosis. We enrolled 47 patients in this open-label, nonrandomized, uncontrolled phase 2 study. The primary endpoint was the proportion of patients with SVR at 12 weeks after cessation of study treatment (SVR12). The overall rate of SVR12 was 89% (95% confidence interval [CI]: 77-97). Rates of SVR12 were higher in patients with genotype 2 than in those with genotype 3, 96% (95% CI: 78-100) and 83% (95% CI: 62-95), respectively. Rates of SVR12 were similar in patients with and without cirrhosis: for genotype 2, 93% of patients with cirrhosis and 100% of patients without cirrhosis achieved SVR12, and for genotype 3, the SVR12 rate was 83% in patients both with and without cirrhosis. One patient discontinued study treatment because of an adverse event and four patients experienced serious adverse events. The most common adverse events were influenza-like illness, fatigue, anemia, and neutropenia. CONCLUSION: In treatment-experienced patients with HCV genotypes 2 and 3, 12-week administration of SOF+Peg-IFN+RBV provided high SVR rates, irrespective of cirrhosis status. No safety concerns were identified.

Sofosbuvir with pegylated interferon alfa-2a and ribavirin for treatment-naive patients with hepatitis C genotype-1 infection (ATOMIC): an open-label, randomised, multicentre phase 2 trial.

BACKGROUND: The uridine nucleotide analogue sofosbuvir is a selective inhibitor of hepatitis C virus (HCV) NS5B polymerase. We assessed the safety and efficacy of sofosbuvir in combination with pegylated interferon alfa-2a (peginterferon) and ribavirin in non-cirrhotic treatment-naive, patients with HCV. METHODS: For this open-label, randomised phase 2 trial, we recruited patients from 42 centres in the USA and Puerto Rico between March 23, 2011, and Sept 21, 2011. Patients were eligible for inclusion if they had chronic HCV infection (genotypes 1, 4, 5, or 6), were aged 18 years or older, and had not previously received treatment for HCV infection. Using a computer-generated randomisation sequence, we randomly assigned patients with HCV genotype-1 to one of three cohorts (A, B, and C; in a 1:2:3 ratio), with randomisation stratified by IL28B (CC vs non-CC allele) and HCV RNA (<800,000 IU/mL vs ≥800,000 IU/mL). Patients received sofosbuvir 400 mg plus peginterferon and ribavirin for 12 weeks (cohort A) or for 24 weeks (cohort B), or 12 weeks of sofosbuvir plus peginterferon and ribavirin followed by 12 weeks of either sofosbuvir monotherapy or sofosbuvir plus ribavirin (cohort C). We enrolled patients with all other eligible genotypes in cohort B. The primary efficacy endpoint was sustained virological response at post-treatment week 24 (SVR24) by intention-to-treat analysis. This trial is registered with ClinicalTrials.gov, number NCT01329978. RESULTS: We enrolled 316 patients with HCV genotype-1: 52 to cohort A, 109 to cohort B, and 155 to cohort C. We assigned 11 patients with HCV genotype-4 and five patients with genotype-6 to cohort B (we detected no patients with genotype 5). In patients with HCVgenotype-1, SVR24 was achieved by 46 patients (89%, 95% CI 77-96) in cohort A, 97 patients (89%, 82-94) in cohort B, and by 135 (87%, 81-92) in cohort C. We detected no difference in the proportion of patients achieving SVR24 in cohort A compared with cohort B (p=0·94), or in cohort C (p=0·78). Nine (82%) of 11 patients with genotype-4 and all five with genotype-6 achieved SVR24. Seven patients, all with genotype-1 infection, relapsed after completion of assigned treatment. The most common adverse events that led to the discontinuation of any study drug--anaemia and neutropenia--were associated with peginterferon and ribavirin treatment. Three (6%) patients in cohort A, 18 (14%) patients in cohort B, and three (2%) patients in cohort C discontinued treatment because of an adverse event. INTERPRETATION: Our findings suggest that sofosbuvir is well tolerated and that there is no additional benefit of extending treatment beyond 12 weeks, but these finding will have to be substantiated in phase 3 trials. These results lend support to the further assessment of a 12 week sofosbuvir regimen in a broader population of patients with chronic HCV genotype-1 infection, including those with cirrhosis. FUNDING: Gilead Sciences.

Identification of a class of HCV inhibitors directed against the nonstructural protein NS4B.

New classes of drugs are needed to combat hepatitis C virus (HCV), an important worldwide cause of liver disease. We describe an activity of a key domain, an amphipathic helix we termed 4BAH2, within a specific HCV nonstructural protein, NS4B. In addition to its proposed role in viral replication, we validate 4BAH2 as essential for HCV genome replication and identify first-generation small-molecule inhibitors of 4BAH2 that specifically prevent HCV replication within cells. Mechanistic studies reveal that the inhibitors target 4BAH2 function by preventing either 4BAH2 oligomerization or 4BAH2 membrane association. 4BAH2 inhibitors represent an additional class of compounds with potential to effectively treat HCV.