A phase 2 study of filibuvir in combination with pegylated IFN alfa and ribavirin for chronic HCV

• Main Authors: Maribel Rodriguez-Torres, Eric M. Yoshida, Patrick Marcellin, Subasree Srinivasan, Vivek S. Purohit, Cunshan Wang, Jennifer L. Hammond, Ph.D.
• Format: Article
• Language: English
• Published: Elsevier 2014-07-01
• Series: Annals of Hepatology
• Subjects: NS5B; Non-nucleoside inhibitor; Treatment naïve; Safety; Efficacy
• Online Access: http://www.sciencedirect.com/science/article/pii/S1665268119308439

Objectives. Filibuvir is a non-nucleoside inhibitor of hepatitis C virus (HCV) polymerase. This study evaluated the safety and efficacy of filibuvir plus pegylated interferon alfa-2a (pegIFN)/ribavirin.Material and methods. Treatment-naïve, HCV genotype-1 patients were randomized to receive filibuvir 300 or 600 mg twice daily (BID) or placebo plus pegIFN (180 Mg/wk) and ribavirin (1,000/1,200 mg BID) for 24 weeks. Filibuvir patients who achieved defined response through week 24 discontinued therapy at week 24. All other patients continued on open-label peglFN/ribavirin through week 48. The primary endpoint was the proportion of patients who achieved sustained virologic response (SVR) defined as HCV RNA < 15 IU/mL at end of treatment (weeks 24 or 48) and week 72.Results. Overall, 288 patients were randomized and treated. SVR was achieved by 41.7, 39.6, and 45.8% of patients in the filibuvir 300 mg, 600 mg, and placebo arms, respectively. While the addition of filibuvir to pegIFN/ribavirin improved on-treatment virologic response parameters, this did not translate into improved SVR rates due to a high rate of virologic relapse following completion of therapy (300 mg: 35.9%; 600 mg: 42.9%; placebo: 25.4%). The most commonly reported adverse events were nausea, fatigue, headache, and insomnia, and were reported at similar rates across arms. Conclusions. Filibuvir plus pegIFN/ribavirin did not improve the percentage of patients achieving SVR compared with administration of pegIFN/ribavirin alone. However, the agent was well tolerated and was associated with higher on-treatment virologic response parameters. Further evaluation of filibuvir in combination with other direct-acting antiviral agents may be considered.