A predictive model for selecting patients with HCV genotype 3 chronic infection with a high probability of sustained virological response to peginterferon alfa-2a/ribavirin

Abstract

Background Access to direct-acting antiviral agents (DAAs) is restricted in some settings; thus, the European Association for the Study of the Liver recommends dual peginterferon/ribavirin (PegIFN/RBV) therapy wherever DAAs are unavailable. HCV genotype (GT) 3 infection is now the most difficult genotype to eradicate and PegIFN/RBV remains an effective option. The goal of this study was to devise a simple predictive score to identify GT3 patients with a high probability of achieving a sustained virologic response (SVR) with PegIFN alfa-2a/RBV therapy. Methods Relationships between baseline characteristics and SVR were explored by multiple logistic regression models and used to develop a simple scoring system to predict SVR using data from 1239 treatment-naive GT3 patients who received PegIFN alfa-2a/RBV for 24 weeks in two large observational cohort studies. Results The score was validated using a database of 473 patients. Scores were assigned for six factors as follows: Age (years) (<40: 2 points; >40 but <55: 1); bodyweight (kg) (<70: 2; <70 but <90: 1); no cirrhosis/transition to cirrhosis (2); ALT <2.5 x ULN (1); platelets (109/L) (>200: 2; >100 but <200: 1); HCV RNA (<400,000 IU/mL: 1). The points are summed to arrive at a score ranging from 0-10 where higher scores indicate higher chances of SVR; 141, 123, 203, 249, 232, and 218 patients had total scores of 0-4, 5, 6, 7, 8, and 9-10, respectively, among whom SVR rates were 45%, 62%, 72%, 76%, 84%, and 89%. Among 622 patients who had scores of 6-10 and HCV RNA <50 IU/mL by treatment week 4 the SVR rate was 86% (532/622). Conclusions A simple baseline scoring system involving age, bodyweight, cirrhosis status, ALT level, platelet count and HCV RNA level can be used to identify treatment-naive Caucasian patients with HCV GT3 infection with a high probability of SVR with PegIFN alfa-2a/RBV therapy.