A Multicenter Study to Clarify the Optimal HCV-RNA Negative Period during Combined Therapy with Pegylated Interferon Plus Ribavirin in Patients with Chronic Hepatitis Caused by HCV Genotype 2

Objective A multicenter open trial was performed to clarify the optimal duration of combined pegylated interferon (Peg-IFN) plus ribavirin therapy in patients with chronic hepatitis caused by HCV genotype 2. Methods A total of 100 patients seen between 2005 and 2007 received the combination therapy for 4 to 52 weeks. The cutoff value of the HCV-RNA-negative (titers under 1.7 Log IU/mL) period during the therapy to predict sustained virological response (SVR) was determined by ROC curve and multivariate logistic regression analyses. The result was validated in 48 patients between 2008 and 2009. Results SVR was achieved in 78 patients. Serum HCV-RNA titers decreased to less than 1.7 Log IU/mL at 4 weeks of the therapy in 60 patients. The SVR rate in these patients was 85%, which was significantly higher than that of remaining 40 patients with a SVR rate of 68%. An HCV-RNA-negative period of >= 17 weeks was selected as the cutoff value, which showed a significant odds ratio of 4.77 for SVR. Among the 35 patients who showed a decrease of the serum HCV-RNA of less than 1.7 Log IU/mL between 8 and 16 weeks of therapy, the SVR rate was significantly higher in 16 patients with a serum HCV-RNA-negative period of >= 17 weeks (94%) than in 19 patients in whom the period was less than 17 weeks (63%). Similar results were obtained in the subsequent validation study. Conclusion Prolonged combined Peg-IFN plus ribavirin therapy, with an HCV-RNA-negative period of >= 17 weeks, yielded good therapeutic outcomes in patients with chronic HCV genotype 2 hepatitis.