Early quantification of HCV core antigen may help to determine the duration of therapy for chronic genotype 2 or 3 HCV infection.

The aim of the present study was to evaluate the utility of hepatitis C virus (HCV) core antigen (coreAg) assessment for the identification of candidates for short-term therapy. Plasma samples from HCV genotype 2 or 3-infected patients participating in the NORDynamIC trial (n=382) comparing 12 and 24 weeks of combination treatment with pegylated interferon-α2a and a fixed dose of 800 mg ribavirin daily were analyzed for coreAg. Among the 126 patients (33% of the intention-to-treat population) achieving HCV coreAg levels in plasma below 0.2 pg/mL when assayed on treatment day 3, sustained viral response (SVR) rates of 86% and 84% were achieved in the 12- and 24-week arms, respectively. Similarly, among patients having received at least 80% of the target dose of both pegylated interferon α-2a and of ribavirin for at least 80% of the target treatment duration (per-protocol analysis), the SVR rates were 89% and 95%, respectively. Twelve weeks of combination treatment may be sufficient for genotype 2 or 3-infected patients achieving HCV coreAg levels below 0.2 pg/mL by day 3, signaling a rapid clearance of HCV viremia.