Resistance Likely to Develop With New Hepatitis C Drugs
by -- A. Agrawal, PhD Updated: Feb 25th 2010
THURSDAY, Feb. 25 (HealthDay News) -- New drugs that block the replication of the hepatitis C virus (HCV) are likely to lead to resistance if given as monotherapy and should be given in combination with pegylated interferon and ribavirin, according to a review in the February issue of Gastroenterology.
Christoph Sarrazin, M.D., and Stefan Zeuzem, M.D., from the J.W. Goethe-University Hospital in Frankfurt am Main, Germany, note that directly acting antiviral (DAA) agents that block HCV replication are currently in clinical trials, but monotherapy increases the risk of resistance due to the rapid replication and genetic heterogeneity of the virus.
The researchers write that patients receiving triple therapies of a DAA agent, pegylated interferon, and ribavirin have significantly improved rates of sustained virologic response compared with interferon and ribavirin alone. However, due to virus heterogeneity, the efficacy of DAA agents will vary between patients. The study also notes that most drugs are targeting HCV genotype 1, but triple therapy is not effective in all patients with this genotype.
"It is important to increase our understanding of mechanisms of resistance mutations, viral breakthrough, and relapse after therapy with DAA agents," Sarrazin and Zeuzem write. "Improving our knowledge of these processes will require more precise and earlier characterization of resistance profiles of patients given monotherapy, long-term follow-up data, and studies with combination therapies."
