Telaprevir for retreatment of HCV infection: review of the REALIZE trial

An estimated 170 million people are chronically infected with HCV, which is a leading cause of cirrhosis, hepatocellular carcinoma and liver transplantation in North America. However, in patients infected with HCV genotype 1, 48 weeks of pegylated IFN-alpha and ribavirin treatment results in a sustained virologic response of only 40-50%. Therefore, development of effective regimens to eradicate HCV has been an urgent priority, especially in those patients who have a predicted low treatment response, partial responders and nonresponders. Telaprevir is a reversible, selective, orally bioavailable inhibitor of the HCV NS3/4A serine protease, and resembles the HCV polypeptide that is cleaved by the viral protease, a necessary step in replication. The REALIZE trial was a Phase III, randomized, double-blind, placebo-controlled study of patients who were previously treated with pegylated IFN-alpha and ribavirin unsuccessfully for chronic genotype 1 HCV infection, with the aim to compare the efficacy, safety and tolerability of telaprevir. This article reviews the background, study design and results of the REALIZE trial, and discusses the significance of these findings in the rapidly evolving treatment regimens for genotype 1 chronic HCV.