The efficacy of interferon (IFN) therapy depends on the hepatitis C virus (HCV) genotype, pretreatment viral load and early viral kinetics. Thus, IFN therapy must be individualized and optimized according to the virological and clinical status of each patient.
A research article to be published on March 28, 2010 in the World Journal of Gastroenterology addresses this question. Dr. Masumoto and his colleagues at Iizuka Hospital proposed the new concept of early viral kinetics in peg-interferon (PEG-IFN) therapy. They defined the "immediate virological response (IVR)" as the loss of serum HCV RNA 7 days after the first administration of PEG-IFN, and scheduled a 12-week treatment course of PEG-IFN for 38 patients who had low pretreatment HCV RNA load and exhibited IVR. As a result, 35 patients (92.1%) achieved sustained virological response (SVR); the elimination of HCV.
Establishing the minimum and yet sufficient IFN therapy period is essential in terms of financial efficiency and for reducing the risk of adverse events. The results of this study provide an important suggestion which will allow future investigations to optimize the treatment regimen of IFN therapy for chronic hepatitis C, especially for the patients who exhibit fast virological response to IFN. IVR, the new concept proposed in this study, should be a simple and useful indicator of early viral kinetics to predict the high probability of SVR.