June 19, 2011

Rapid emergence of telaprevir resistant hepatitis C virus strain from wild type clone in vivo

Hepatology. 2011 May 29. doi: 10.1002/hep.24460. [Epub ahead of print]
 
 
Department of Medicine and Molecular Science, Division of Frontier Medical Science, Programs for Biomedical Research, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan; Liver Research Project Center, Hiroshima University, Hiroshima, Japan.

Abstract

Telaprevir is a potent inhibitor of hepatitis C virus (HCV) NS3-4A protease. However, emergence of drug resistant strains during therapy is a serious problem, and the susceptibility of resistant strains to interferon (IFN), as well as the details of the emergence of mutant strains in vivo is not known. We previously established an infectious model of HCV using human hepatocyte chimeric mice. Using this system, we investigated the biological properties and mode of emergence of mutants by ultra-deep sequencing technology. Chimeric mice were injected with serum samples obtained from a patient who had developed viral breakthrough during telaprevir monotherapy with strong selection for resistance mutations (A156F [92.6%]). Mice infected with the resistant strain (A156F [99.9%]) developed only low-level viremia, and the virus was successfully eliminated with interferon therapy. As observed in patients, telaprevir monotherapy in viremic mice resulted in breakthrough, with selection for mutations that confer resistance to telaprevir (e.g., a high frequency of V36A [52.2%]). Mice were injected intrahepatically with HCV genotype 1b clone KT-9 with or without an introduced resistance mutation, A156S, in the NS3 region, and treated with telaprevir. Mice infected with the A156S strain developed lower level viremia compared to the wild type strain but showed strong resistance to telaprevir treatment. Although mice injected with wild type HCV showed a rapid decline in viremia at the beginning of therapy, a high frequency (11%) of telaprevir-resistant NS3 V36A variants emerged two weeks after the start of treatment. Conclusion: Using deep sequencing technology and a genetically engineered HCV infection system, we showed that the rapid emergence of telaprevir-resistant HCV was induced by mutation from the wild type strain of HCV in vivo. (HEPATOLOGY 2011.).

Copyright © 2011 American Association for the Study of Liver Diseases.

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